Last Lecture Flashcards

Question 1

Q

The cardiovascular system consists of what four things

Answer

A

The cardiovascular system consists of the heart, arteries, veins, and capillaries.

Question 2

Q

The heart has two main chambers and four valves. Name them
Which valve is Located between the right atrium and right ventricle?
Which valve is Located between the right ventricle and the pulmonary artery?

Which valve is Located between the left atrium and left ventricle.

Which valve is Located between the left ventricle and the aorta?

Answer

A

Atrium
Ventricles

The heart has four valves:

Tricuspid Valve - Located between the right atrium and right ventricle.
Pulmonary Valve - Located between the right ventricle and the pulmonary artery.
Mitral Valve - Located between the left atrium and left ventricle.
Aortic Valve - Located between the left ventricle and the aorta.

These valves ensure one-way blood flow through the heart’s chambers and into the major arteries.

Question 3

Q

Why is the tricuspid valve called so?

Answer

A

It has three cups

Question 4

Q

Explain how blood flows through the heart starting from the right ventricle.

Answer

A

Superior and inferior vena cava to the right atrium to the right ventricle through the tricuspid valve. The pathway you’re describing involves the circulation of blood through the heart and lungs. Here’s how the aorta and left atrium fit into this process:

Right Ventricle to Pulmonary Artery:
- Deoxygenated blood from the right ventricle is pumped into the pulmonary artery.
- The pulmonary artery carries this deoxygenated blood to the lungs for oxygenation.
Lungs:
- In the lungs, the blood exchanges carbon dioxide for oxygen. Oxygen is picked up by the red blood cells in the capillaries surrounding the alveoli (air sacs), and carbon dioxide is released into the alveoli to be exhaled.
Pulmonary Veins to Left Atrium:
- Oxygenated blood returns from the lungs to the heart via the pulmonary veins.
- The pulmonary veins deliver this oxygen-rich blood to the left atrium of the heart.
Left Atrium to Left Ventricle:
- The left atrium receives blood from the pulmonary veins and contracts, pushing blood into the left ventricle.
Left Ventricle to Aorta:
- The left ventricle, being the strongest chamber of the heart, pumps oxygenated blood into the aorta.
- The aorta is the largest artery in the body and carries oxygen-rich blood away from the heart to be distributed throughout the body.
Aorta to Systemic Circulation:
- From the aorta, oxygenated blood flows into smaller arteries, arterioles, and then into capillaries throughout the body’s tissues.
- In the capillaries, oxygen and nutrients are exchanged for carbon dioxide and waste products.
Systemic Veins to Right Atrium:
- Deoxygenated blood returns from the body tissues via systemic veins to the right atrium of the heart.
Right Atrium to Right Ventricle:
- The right atrium receives deoxygenated blood from the systemic veins and contracts, pushing blood into the right ventricle to begin the pulmonary circulation again.

In summary, the aorta plays a crucial role in systemic circulation by distributing oxygen-rich blood from the left ventricle to the body tissues. The left atrium receives oxygenated blood from the pulmonary veins before it enters the left ventricle. This process ensures that oxygenated blood is delivered to the body’s tissues via the systemic circulation, while deoxygenated blood is sent to the lungs for oxygenation via the pulmonary circulation.

Question 5

Q

What are the two main parts of the respiratory system
State the functions of each part and the structures associated with each part

Answer

A

Conducting zone and the respiratory zone

Conducting Zone:
- Function: The conducting zone consists of a series of interconnected passages and structures that facilitate the movement of air into and out of the lungs. It just conducts air towards where the gaseous exchange will occur.
  It includes:
  - Nose and Nasal Cavities: Air enters the respiratory system through the nostrils and passes through the nasal cavities, where it is warmed, humidified, and filtered.
  - Pharynx: Commonly known as the throat, it serves as a passage for both air and food.
  - Larynx: Contains the vocal cords and serves as the airway entrance to the trachea.
  - Trachea: Also known as the windpipe, it is a rigid tube that conducts air from the larynx to the bronchi.
  - Bronchi and Bronchioles: The trachea branches into the left and right bronchi, which further divide into smaller bronchioles. These structures conduct air deeper into the lungs.
  - Terminal Bronchioles: The smallest branches of the bronchioles before they enter the respiratory zone.
Respiratory Zone:
- Function: The respiratory zone is where gas exchange occurs, allowing oxygen to enter the bloodstream and carbon dioxide to exit. It includes:
  - Respiratory Bronchioles: Branches of the terminal bronchioles that lead into alveolar ducts.
  - Alveolar Ducts: Thin-walled passages that end in clusters of air sacs called alveoli.
  - Alveoli: Tiny air sacs where gas exchange takes place. They are surrounded by capillaries, allowing for the diffusion of oxygen into the bloodstream and carbon dioxide out of the bloodstream.

In summary, the conducting zone of the respiratory system includes the structures responsible for conducting air into and out of the lungs, while the respiratory zone is where gas exchange occurs between the air in the alveoli and the blood in the pulmonary capillaries. Together, these zones ensure efficient ventilation and oxygenation of the blood throughout the body.

Question 6

Q

How many lobes does the left lung have and how many does the right have?
How many fissures does each lung have
What is the diaphragm?
Which fissure divides the left lobe?
Which fissures divide the right lobe? There are two layers that cover the lungs. Visceral and parietal. Which covers the lungs themselves and which covers the cover😂. Or covers the diaphragm and stuff. What’s the name of the space between the visceral and parietal layers? Which of the layers is responsible for reducing friction between the lungs as it expands? Which maintains negative pressure in the space between the two layers

Answer

A

Right has three and left has two.

The lungs are paired organs located within the thoracic cavity on either side of the heart. Here’s an overview of the right and left lungs:

Right Lung:
- Structure: The right lung is larger than the left lung and consists of three lobes:
  - Upper Lobe: Located above the horizontal fissure, it extends from the apex of the lung to the level of the fourth rib.
  - Middle Lobe: Found between the horizontal and oblique fissures, it is smaller and not always present in everyone.
  - Lower Lobe: Below the oblique fissure, it extends from the level of the fifth rib to the diaphragm.
- Features: The right lung has two fissures that divide it into these lobes—the horizontal fissure and the oblique fissure. The oblique divides it into upper and lower and the horizontal divides it into upper and middle lung lobes
Left Lung:
- Structure: The left lung is slightly smaller to accommodate space for the heart and consists of two lobes:
  - Upper Lobe: Extends from the apex of the lung to the level of the fourth rib.
  - Lower Lobe: Extends from the level of the fifth rib to the diaphragm.
- Features: The left lung has a single oblique fissure that divides it into the upper and lower lobes.

Both lungs are enclosed within the pleural membranes, which consist of two layers (visceral and parietal pleura) that surround and protect the lungs while facilitating movement during breathing. The respiratory bronchioles, alveolar ducts, and alveoli within each lung facilitate gas exchange, where oxygen is absorbed into the bloodstream and carbon dioxide is expelled from the body.

In summary, while the right lung is larger and has three lobes divided by two fissures, the left lung is smaller with two lobes divided by a single fissure. Together, they play a crucial role in respiration and maintaining proper oxygenation of the blood.

The visceral pleura and parietal pleura are two layers of the pleura, a double-layered membrane that surrounds the lungs and lines the chest cavity.

Location: The visceral pleura is the inner layer that directly covers the surface of the lungs, including the fissures between the lobes.
Function: It is closely adhered to the lung tissue and moves with the lungs during respiration. The visceral pleura is essential in creating a smooth, frictionless surface for the lungs to expand and contract against the chest wall.

Location: The parietal pleura is the outer layer that lines the inner surface of the chest wall, the diaphragm, and the mediastinum.
Function: It helps maintain the negative pressure within the pleural cavity, which is essential for lung expansion during inhalation. It also provides a protective barrier and secretes pleural fluid to reduce friction between the lungs and chest wall during breathing.

The space between the visceral and parietal pleura is called the pleural cavity. It contains a small amount of lubricating fluid known as pleural fluid, which reduces friction and allows the lungs to move smoothly during breathing.

The visceral and parietal pleurae are continuous with each other at the root of the lung, where the blood vessels, bronchi, and nerves enter and exit the lungs.

Diaphragm:
It is a musculotendinous structure that divides the thoracic and abdominal cavity

Question 7

Q

State the sinuses in the body
State the differences between the glottis and epiglottis

Answer

A

Frontal and sphenoid sinuses

The glottis and epiglottis are structures located within the throat (pharynx) and larynx, playing essential roles in both respiration and swallowing:

Glottis:
- Location: The glottis is the opening between the vocal cords within the larynx.
- Function: It acts as the passageway for air to move into the trachea during breathing. The glottis opens wide during inhalation and closes partially during swallowing to prevent food or liquids from entering the trachea.
- Vocal Cord Function: The glottis also houses the vocal cords (vocal folds), which vibrate when air passes through during speech production, allowing us to produce sound.
Epiglottis:
- Location: The epiglottis is a flap-like structure made of elastic cartilage located at the base of the tongue, just behind the root of the tongue.
- Function: During swallowing, the epiglottis folds down over the glottis to cover it, forming a lid-like structure. This action prevents food and liquids from entering the trachea and directs them instead into the esophagus, which leads to the stomach.
- Protection: The epiglottis acts as a protective mechanism to ensure that food and liquids are directed to the digestive system while keeping the airway clear for breathing.

In summary, the glottis serves as the opening between the vocal cords within the larynx, facilitating airflow during respiration and sound production during speech. The epiglottis, on the other hand, is a cartilaginous flap that prevents food and liquids from entering the trachea during swallowing, ensuring proper separation of the respiratory and digestive pathways. These structures are crucial for both respiratory function and the process of swallowing safely.

Question 8

Q

Explain what happens during exhalation and inhalation of air
During inhalation,does the diaphragm contract or relax?
During inhalation, does the external intercostal muscles contract or relax?
When the volume of the thoracic cavity increases, what happens to the pressure in the lungs?

Due to the pressure difference between the atmospheric pressure and the reduced pressure inside the lungs, air rushes? In or out?
During exhalation,the ribs move up or down?
The diaphragm
What happens when the elastic tissues in the lungs and chest wall recoil as the muscles relax, exerting pressure on the air inside the lungs? Does the pressure in the lungs become higher or lower than the atmospheric pressure?
What does this lead to? Air flow out of the lungs or inside the lungs?

Answer

A

During respiration, both inhalation (inspiration) and exhalation (expiration) are processes that involve the movement of air into and out of the lungs. Here’s a detailed explanation of what happens during each phase:

Diaphragm Contraction:
- The process begins with the contraction of the diaphragm, a dome-shaped muscle located at the base of the lungs. So when air is drawn in,the ribs move out and the diaphragm moves down
- When the diaphragm contracts, it moves downwards and flattens, increasing the vertical dimension of the thoracic cavity. To allow more air to enter.
External Intercostal Muscles Contraction:
- Simultaneously, the external intercostal muscles between the ribs contract.
- This contraction elevates the rib cage and expands the thoracic cavity laterally.
Thoracic Cavity Expansion:
- The combined actions of the diaphragm and external intercostal muscles expand the thoracic cavity in both vertical and lateral dimensions.
- As a result, the volume of the thoracic cavity increases, and the pressure inside the lungs decreases.
Airflow into the Lungs:
- Due to the pressure difference between the atmospheric pressure and the reduced pressure inside the lungs, air rushes into the respiratory tract through the nose and mouth.
- The air travels through the conducting airways (nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles) and finally reaches the alveoli (air sacs) in the lungs.

Diaphragm Relaxation:
- Exhalation begins with the relaxation of the diaphragm and external intercostal muscles. When air is forced out,ribs move down and diaphragm moved up.
- The diaphragm returns to its dome shape due to its elasticity, decreasing the vertical dimension of the thoracic cavity.
Elastic Recoil of Lungs:
- As the muscles relax, the rib cage and thoracic cavity return to their resting positions.
- The elastic tissues in the lungs and chest wall recoil, exerting pressure on the air inside the lungs.
Airflow out of the Lungs:
- The pressure inside the lungs becomes higher than the atmospheric pressure.
- Air flows out of the lungs passively, following the pressure gradient, through the conducting airways and out of the nose or mouth.

Inhalation: Diaphragm and external intercostal muscles contract, increasing thoracic cavity volume, decreasing lung pressure, and allowing air to enter the lungs.
Exhalation: Diaphragm and external intercostal muscles relax, decreasing thoracic cavity volume, increasing lung pressure, and causing air to leave the lungs.

These processes of inhalation and exhalation are controlled involuntarily by the respiratory centers in the brainstem, which adjust breathing rate and depth based on the body’s needs for oxygen and removal of carbon dioxide.

The confusion might arise from the terms used and the different pressures involved in breathing. Let’s clarify how pressure changes during inhalation and exhalation:

Inhalation (Inspiration):
- Diaphragm and External Intercostal Muscles Contract: This increases the volume of the thoracic cavity.
- Intrapleural Pressure Decreases: As the thoracic cavity expands, the pressure within the pleural cavity (intrapleural pressure) becomes more negative.
- Intrapulmonary Pressure Decreases: The decrease in intrapleural pressure causes the lungs to expand, which lowers the pressure inside the lungs (intrapulmonary pressure) below atmospheric pressure.
- Air Flows In: Air moves into the lungs due to the pressure gradient (higher atmospheric pressure compared to lower intrapulmonary pressure).
Exhalation (Expiration):
- Diaphragm and External Intercostal Muscles Relax: This decreases the volume of the thoracic cavity.
- Intrapleural Pressure Increases: As the thoracic cavity contracts, intrapleural pressure becomes less negative (more positive).
- Intrapulmonary Pressure Increases: The increase in intrapleural pressure causes the lungs to contract, raising the pressure inside the lungs (intrapulmonary pressure) above atmospheric pressure.
- Air Flows Out: Air exits the lungs due to the pressure gradient (higher intrapulmonary pressure compared to lower atmospheric pressure).

Intrapleural Pressure: Decreases during inhalation and increases during exhalation.
Intrapulmonary Pressure: Decreases during inhalation and increases during exhalation.

So, during inhalation, intrapulmonary pressure decreases, not increases. This decrease in intrapulmonary pressure is what allows air to flow into the lungs. The increase in thoracic volume due to diaphragm and intercostal muscle contraction causes the intrapleural pressure to become more negative, which facilitates this process.

Question 9

Q

Nasal hair and mucous lining filter the air from all the dirts.

Answer

A

Air moves into nose and mouth and enters into the pharynx and larynx and meters into the trachea and into the left and right bronchi and into the bronchioles and into the alveoli where oxygen is absorbed from the air inhaled in and the oxygen is diffused into the blood capillaries. Carbon dioxide-rich blood returns to the lungs via the pulmonary arteries.
• Carbon dioxide diffuses from the blood in the capillaries into the alveoli.
• During exhalation, carbon dioxide is expelled from the lungs into the external environment.
carbon dioxide produced by cellular metabolism is carried back to the lungs via the bloodstream, where it diffuses into the alveoli and is exhaled from the body during exhalation.

Question 10

Q

What is the structure of the alveoli
Which alveoli cells secrete surfactant?
What is the function of surfactant ?

Answer

A

Alveoli are tiny, grape-like air sacs found in the lungs where gas exchange occurs. They are lined with a single layer of epithelial cells and are surrounded by a network of blood capillaries. Here’s how they are structured:

Alveolar Structure:
- Epithelial Cells: The walls of each alveolus (singular of alveoli) are composed of two main types of epithelial cells:
  - Type I Alveolar Cells: These are squamous epithelial cells that form the majority of the alveolar wall. They are extremely thin to facilitate the diffusion of gases (oxygen and carbon dioxide) between the alveoli and capillaries.
  - Type II Alveolar Cells: These are cuboidal epithelial cells that secrete surfactant, a substance that reduces surface tension within the alveoli and prevents them from collapsing. Squamous Epithelium and Facilitation of Diffusion

Squamous epithelial cells are flat and thin, creating a minimal barrier for the exchange of gases, nutrients, and waste products. This thinness allows for easy diffusion, making squamous epithelium ideal for lining surfaces involved in passive diffusion, such as:

•	Alveoli in the lungs: Where oxygen and carbon dioxide diffuse across the thin squamous cells into and out of the blood.
•	Endothelium of blood vessels: Where nutrients and waste products are exchanged between blood and tissues.

Cuboidal Cells and Surfactant Secretion

Cuboidal cells are more cube-shaped and often contain more cytoplasm than squamous cells. In the lungs, Type II alveolar cells (cuboidal cells) are responsible for secreting surfactant. Surfactant is a lipid-protein complex that reduces surface tension in the alveoli, preventing them from collapsing and allowing for easier expansion during breathing

Alveolar Septa:
- The alveoli are separated from each other by thin walls called alveolar septa (singular: septum).
- Each septum contains a network of elastic and collagenous fibers that provide structural support and help maintain the shape of the alveoli.
- Capillaries run through the alveolar septa, allowing for the exchange of gases between the air in the alveoli and the blood in the capillaries.
Function:
- Gas Exchange: Oxygen from the inhaled air diffuses across the thin alveolar membrane and into the bloodstream in the capillaries, while carbon dioxide diffuses from the bloodstream into the alveoli to be exhaled.
- Surface Area: The large surface area of alveoli (approximately 70 square meters in adults) maximizes the efficiency of gas exchange in the lungs.

In summary, alveoli are crucial structures in the respiratory system, where the exchange of oxygen and carbon dioxide occurs. They are lined with thin epithelial cells and separated by alveolar septa, which support gas exchange and maintain the structural integrity of the lung tissue.

Question 11

Q

Which plane of the body divides it into dorsal and ventral regions?
A. Transverse
B. Axial
C. Coronal
D. Sagittal

Which anatomical plane divides the body into anterior (front) and posterior (back) sections?
- A) Sagittal Plane
- B) Coronal Plane
- C) Transverse Plane
- D) Oblique Plane
What term is used to describe a structure that is closer to the head than another structure?
- A) Inferior
- B) Lateral
- C) Superior
- D) Distal
Which anatomical term refers to the back side of the body?
- A) Ventral
- B) Anterior
- C) Dorsal
- D) Medial
- **
Which plane divides the body into left and right sections?
- A) Coronal Plane
- B) Transverse Plane
- C) Axial Plane
- D) Sagittal Plane
What term describes a position farther away from the trunk of the body or point of origin?
- A) Medial
- B) Proximal
- C) Distal
- D) Superior
In the anatomical position, what term describes the palm side of the hand?
- A) Dorsal
- B) Plantar
- C) Palmar
- D) Ventral
Which plane divides the body into upper (superior) and lower (inferior) sections?
- A) Coronal Plane
- B) Sagittal Plane
- C) Transverse Plane
- D) Frontal Plane
What movement describes rotating the forearm so that the palm faces upward?
- A) Pronation
- B) Supination
- C) Flexion
- D) Extension
If a structure is described as being ‘medial,’ where is it located relative to the body?
- A) Closer to the head
- B) Closer to the feet
- C) Closer to the midline
- D) Farther from the midline
Which term refers to the bottom or sole of the foot?
- A) Dorsal
- B) Ventral
- C) Palmar
- D) Plantar
Which term is used to describe the movement of a body part away from the midline?

•	A) Flexion
•	B) Adduction
•	C) Abduction
•	D) Extension


12.	Which anatomical term refers to a structure that is closer to the midline than another structure?

•	A) Lateral
•	B) Distal
•	C) Medial
•	D) Proximal

Answer

A

The plane of the body that divides it into dorsal (back) and ventral (front) regions is the coronal plane (also known as the frontal plane).

Anatomical planes are imaginary lines used to divide the body into sections to describe locations, movements, and structures more precisely. Here are the main anatomical planes:

Coronal Plane (Frontal Plane):
- Divides the body into: Dorsal (posterior/back) and ventral (anterior/front) regions.
- Orientation: Vertical plane that runs from side to side.
- Uses: Helps in describing locations and movements relative to the front and back of the body.
Sagittal Plane:
- Divides the body into: Left and right sections.
- Orientation: Vertical plane that runs from front to back.
- Uses: Helps in describing locations and movements relative to the left and right sides of the body. A midsagittal plane (or median plane) divides the body into equal left and right halves, while parasagittal planes divide it into unequal left and right sections.
Transverse Plane (Horizontal Plane):
- Divides the body into: Superior (upper) and inferior (lower) regions.
- Orientation: Horizontal plane that runs perpendicular to the coronal and sagittal planes.
- Uses: Helps in describing locations and movements relative to the top and bottom of the body.
Axial Plane:
- Alternative Term for Transverse Plane: Sometimes used interchangeably with the transverse plane in some contexts.
- Orientation: Same as the transverse plane, dividing the body into superior and inferior parts.

The coronal plane is used to describe structures and movements in terms of their position relative to the front and back of the body.
The sagittal plane and transverse plane serve different purposes for dividing the body into left-right and upper-lower sections, respectively.
1. B) Coronal Plane
2. C) Superior
3. C) Dorsal
4. D) Sagittal Plane
5. C) Distal
6. C) Palmar
7. C) Transverse Plane
8. B) Supination
9. C) Closer to the midline
10. D) Plantar
11. C) Abduction
12. C) Medial

I see where the confusion might come from. Let’s clarify:

Question: In the anatomical position, what term describes the palm side of the hand?
- A) Dorsal
- B) Plantar
- C) Palmar
- D) Ventral

Answer Explanation:
- Palmar (C): This specifically refers to the palm side of the hand.
- Ventral (D): This refers to the “front” of the body, but it is a more general term and not specifically for the palm of the hand.

While “ventral” could be seen as a broader term referring to the front side, the more specific anatomical term for the palm side of the hand is “palmar.” Hence, the correct answer is C) Palmar.

Let me know if you’d like any more explanations!

Anatomical terms of position and direction are used to describe the location of structures in relation to each other in the human body. Here is a breakdown of the key anatomical terms:

Anterior (Ventral): Refers to the front of the body or closer to the front. For example, the sternum (breastbone) is anterior to the heart.
Posterior (Dorsal): Refers to the back of the body or closer to the back. For example, the spine is posterior to the stomach.
Superior (Cranial): Refers to a position above or higher than another part of the body. For example, the head is superior to the chest.
Inferior (Caudal): Refers to a position below or lower than another part of the body. For example, the stomach is inferior to the lungs.
Medial: Refers to a position closer to the midline of the body. For example, the nose is medial to the eyes.
Lateral: Refers to a position farther from the midline of the body. For example, the ears are lateral to the nose.
Proximal: Refers to a position nearer to the trunk or the point of origin of a structure. For example, the elbow is proximal to the wrist.
Distal: Refers to a position farther from the trunk or the point of origin of a structure. For example, the fingers are distal to the elbow.

Palmar: Refers to the palm side of the hand (ventral surface).
Dorsal (Hand): Refers to the back of the hand.
Plantar: Refers to the bottom (sole) of the foot.
Dorsal (Foot): Refers to the top of the foot.

Flexion: Bending a joint to decrease the angle between two bones or body parts. For example, bending the elbow or knee.
Extension: Straightening a joint to increase the angle between two bones or body parts. For example, straightening the elbow or knee.
Abduction: Movement away from the midline of the body. For example, lifting the arm sideways away from the body.
Adduction: Movement toward the midline of the body. For example, bringing the arm down to the side of the body.
Pronation: Rotation of the forearm so that the palm faces downward.
Supination: Rotation of the forearm so that the palm faces upward.

These terms help provide clear and consistent descriptions of anatomical positions and movements, ensuring that healthcare professionals and students understand each other when describing locations and actions in the body.

Question 12

Q

Question: The directional term “superior” in anatomy means which of the following?

A. Cephalic
B. Ventral
C. Caudal
D. Dorsal

Question: The “anatomical position” could be described as which of the following?

A. Lying down prone
B. Lying down supine
C. Standing displaying the ventral surface of the body
D. Standing with arms and legs abducted

Question: Which list below contains the four types of tissue?

A. Extracellular fluid, skeletal tissue, glandular tissue, connective tissue
B. Extracellular fluid, muscle tissue, glandular tissue, cartilaginous tissue
C. Neural tissue, skeletal tissue, epithelial tissue, cartilaginous tissue
D. Neural tissue, muscle tissue, epithelial tissue, connective tissue

Question: Which of the following is NOT a “long” bone?

A. The humerus
B. The tibia
C. A carpal
D. A metacarpal

Question: Which bone of the head has a synovial joint?

A. The sphenoid
B. The maxilla
C. The mandible
D. The hyoid

Question: Which term below refers to a depression in a bone?

A. Tuberosity
B. Fossa
C. Tubercle
D. Condyle

Answer

A

Question: The directional term “superior” in anatomy means which of the following?

A. Cephalic
- Explanation: “Superior” means towards the head or upper part of the body. “Cephalic” is a synonym for “superior” in anatomical terms, as it refers to the head or direction towards the head.
B. Ventral: This term means towards the front of the body. It is not synonymous with “superior,” which refers to the vertical axis (upwards).
C. Caudal: This term means towards the tail or lower part of the body. It is opposite of “superior.”
D. Dorsal: This term means towards the back of the body. It does not mean “superior”; it refers to the posterior aspect.

Question: The “anatomical position” could be described as which of the following?

C. Standing displaying the ventral surface of the body
- Explanation: The anatomical position is when the body is standing upright, facing forward, with arms at the sides and palms facing forward. This position shows the ventral (front) surface of the body.
A. Lying down prone: Prone means lying face down, which is not the anatomical position.
B. Lying down supine: Supine means lying face up, not the anatomical position which is standing.
D. Standing with arms and legs abducted: In the anatomical position, the arms are at the sides, not abducted (moved away from the body).

Question: Which list below contains the four types of tissue?

D. Neural tissue, muscle tissue, epithelial tissue, connective tissue.
- Explanation: The four basic types of tissue in the body are neural (nervous) tissue, muscle tissue, epithelial tissue, and connective tissue.
A. Extracellular fluid, skeletal tissue, glandular tissue, connective tissue: Extracellular fluid and skeletal tissue are not primary tissue types. Glandular tissue is part of epithelial tissue.
B. Extracellular fluid, muscle tissue, glandular tissue, cartilaginous tissue: Extracellular fluid and cartilaginous tissue are not primary tissue types. Glandular tissue is a type of epithelial tissue.
C. Neural tissue, skeletal tissue, epithelial tissue, cartilaginous tissue: Skeletal and cartilaginous tissues are specific types of connective tissue, not primary tissue types.

Question: Which of the following is NOT a “long” bone?

C. A carpal
- Explanation: Carpal bones are classified as short bones, not long bones. Long bones are characterized by their length being greater than their width and include the humerus, tibia, and metacarpal.
A. The humerus: A long bone in the upper arm.
B. The tibia: A long bone in the lower leg.
D. A metacarpal: A long bone in the hand.

Question: Which bone of the head has a synovial joint?

C. The mandible
- Explanation: The mandible (lower jaw) forms a synovial joint with the temporal bone of the skull, known as the temporomandibular joint (TMJ).
A. The sphenoid: A bone in the skull but does not form a synovial joint.
B. The maxilla: A bone in the upper jaw but does not form a synovial joint.
D. The hyoid: A bone in the neck but does not form a synovial joint.

Question: Which term below refers to a depression in a bone?

B. Fossa
- Explanation: A fossa is a depression or hollow in a bone, often serving as a site for muscle attachment or articulation.
A. Tuberosity: A large, rounded projection on a bone, often for muscle attachment.
C. Tubercle: A small, rounded projection on a bone, also often for muscle attachment.
D. Condyle: A rounded end of a bone that articulates with another bone, often forming a joint.

Question 13

Q

Here are the MCQ questions based on the explanations:

Which one is NOT a function of the stomach?
- A. Digestion of fats
- B. Digestion of proteins
- C. Mechanical breakdown of food
- D. Absorption of nutrients
In what part of the kidney are the glomeruli located?
- A. In the cortex
- B. In the medulla
- C. In the renal pelvis
- D. In the ureter
Which list of blood vessels shows the correct order of blood flow in the kidney tubule?
- A. Glomerulus, efferent arteriole, afferent arteriole, peritubular capillaries
- B. Afferent arteriole, glomerulus, efferent arteriole, peritubular capillaries
- C. Efferent arteriole, glomerulus, afferent arteriole, peritubular capillaries
- D. Peritubular capillaries, afferent arteriole, glomerulus, efferent arteriole
Which list of structures shows the correct order in which urine passes through them on the way to the bladder?
- A. Minor calyx, major calyx, renal pelvis, papilla, ureter
- B. Major calyx, minor calyx, renal pelvis, papilla, ureter
- C. Papilla, minor calyx, major calyx, renal pelvis, ureter
- D. Renal pelvis, major calyx, minor calyx, papilla, ureter
Which of the following may be said of the renal medulla?
- A. It produces hormones like adrenaline.
- B. It contains the renal cortex and glomeruli.
- C. It is involved in blood filtration and hormone production.
- D. It contains the pyramids and columns.
The renal tubule of the nephron includes which of the following structures?
- A. Proximal convoluted tubule, glomerulus, collecting duct, papilla
- B. Distal convoluted tubule, renal pelvis, ascending limb of Loop of Henle, ureter
- C. Descending limb of Loop of Henle, collecting duct, distal convoluted tubule, ascending limb of Loop of Henle
- D. Proximal convoluted tubule, major calyx, minor calyx, collecting duct

Answer

A

Which one is NOT a function of the stomach?
- A. Digestion of fats
  - Explanation: The stomach mainly functions to digest proteins through the action of pepsin and to mechanically break down food into smaller particles. Fat digestion primarily occurs in the small intestine, specifically in the duodenum, where bile and pancreatic enzymes aid in the emulsification and digestion of fats.
In what part of the kidney are the glomeruli located?
- A. In the cortex
  - Explanation: The glomeruli are clusters of capillaries involved in blood filtration and are located in the renal cortex. The renal medulla contains the renal pyramids and is involved in urine concentration and transport.
Which list of blood vessels shows the correct order of blood flow in the kidney tubule?
- B. Afferent arteriole, glomerulus, efferent arteriole, peritubular capillaries
  - Explanation: Blood flows through the kidney in a specific sequence: first entering the glomerulus via the afferent arteriole for filtration, then leaving through the efferent arteriole. After filtration, blood is carried to the peritubular capillaries for nutrient and waste exchange. This sequence is essential for proper kidney function and blood filtration.
Which list of structures shows the correct order in which urine passes through them on the way to the bladder?
- C. Papilla, minor calyx, major calyx, renal pelvis, ureter
  - Explanation: Urine formation starts in the nephron and exits through the renal papillae into the minor calyces, which then combine into major calyces. The major calyces drain into the renal pelvis, which collects urine and channels it to the ureter. This sequence is critical for the efficient drainage and transport of urine from the kidneys to the bladder.
Which of the following may be said of the renal medulla?
- D. It contains the pyramids and columns.
  - Explanation: The renal medulla is the inner part of the kidney and contains renal pyramids (striated structures that contain the collecting ducts) and renal columns (extensions of the cortex between pyramids). It plays a crucial role in concentrating urine. The medulla does not produce hormones like adrenaline; this function is attributed to the adrenal glands, which are located on top of the kidneys.
The renal tubule of the nephron includes which of the following structures?
- C. Descending limb of Loop of Henle, collecting duct, distal convoluted tubule, ascending limb of Loop of Henle.
  - Explanation: The renal tubule is the part of the nephron responsible for reabsorption and secretion of various substances. It includes:
    - Proximal Convoluted Tubule (PCT): Initial segment where significant reabsorption occurs.
    - Descending Limb of Loop of Henle: Permeable to water, allowing for concentration of urine.
    - Ascending Limb of Loop of Henle: Impermeable to water, actively transports ions.
    - Distal Convoluted Tubule (DCT): Further fine-tuning of ion and water balance.
    - Collecting Duct: Final urine concentration and transport to renal pelvis.
  - The incorrect options include structures not part of the renal tubule or incorrectly ordered.

These questions assess understanding of kidney anatomy and physiology, urine formation, and the structure and function of renal blood vessels.

Question 14

Q

To which of the following does the term “respiration” NOT apply?
A. The conversion of carbon dioxide to bicarbonate ions for transport to
the
lungs
B. The exchange of gases between alveolar air and capillary blood
13 Respiratory System
C. The derivation of energy from organic molecules in the cells
D. The exchange of gases between capillary blood and body tissues

Answer

A

The term “respiration” generally refers to processes involved in the exchange and utilization of gases (oxygen and carbon dioxide) in the body. Let’s analyze each option:

A. The conversion of carbon dioxide to bicarbonate ions for transport to the lungs
- This process is part of the transport and regulation of gases in the blood, which is involved in respiration, specifically in the context of how CO2 is transported from tissues to the lungs.

B. The exchange of gases between alveolar air and capillary blood
- This describes external respiration (or pulmonary respiration), where gas exchange occurs between the air in the alveoli and the blood in the capillaries of the lungs.

C. The derivation of energy from organic molecules in the cells
- This process is known as cellular respiration or metabolism, where cells produce energy (ATP) through the oxidation of nutrients. It is a crucial part of overall respiration but not typically considered part of the respiratory system’s function in terms of gas exchange.

D. The exchange of gases between capillary blood and body tissues
- This describes internal respiration (or tissue respiration), where gas exchange occurs between the blood in capillaries and the body tissues.

C. The derivation of energy from organic molecules in the cells

Explanation: While cellular respiration (the derivation of energy from organic molecules) is closely related to the overall process of respiration, it specifically refers to the biochemical processes within cells that produce energy. The other options are related to the physiological processes of the respiratory system, involving the exchange and transport of gases.

Question 15

Q

What happens to blood pressure in the glomerulus when the efferent arteriole constricts?
• A. Increases
• B. Decreases
• C. Remains the same
• D. Fluctuates

Which vessel collects blood from the peritubular capillaries?
•	A. Afferent arteriole
•	B. Efferent arteriole
•	C. Renal vein
•	D. Glomerulus

Which part of the kidney contains the glomeruli?
- A. Renal medulla
- B. Renal pelvis
- C. Renal cortex
- D. Renal column
What is the primary function of the renal pyramids?
- A. Blood filtration
- B. Urine concentration and transport
- C. Hormone production
- D. Immune response
Where does urine flow after it leaves the renal papillae?
- A. Minor calyx
- B. Major calyx
- C. Renal pelvis
- D. Ureter
Which vessel supplies blood to the glomerulus?
- A. Efferent arteriole
- B. Peritubular capillaries
- C. Afferent arteriole
- D. Renal vein
What is the function of the efferent arteriole in the kidney?
- A. Blood filtration
- B. Regulating blood pressure in the glomerulus
- C. Reabsorption of water
- D. Nutrient exchange
Which structure collects urine from the major calyces?
- A. Renal pelvis
- B. Ureter
- C. Minor calyx
- D. Collecting duct
What is the role of the peritubular capillaries?
- A. Blood filtration
- B. Reabsorption and secretion
- C. Blood supply to glomerulus
- D. Urine concentration
Where does urine formation begin in the nephron?
- A. Proximal convoluted tubule
- B. Descending limb of Loop of Henle
- C. Glomerulus
- D. Collecting duct
Which structure in the nephron is responsible for the reabsorption of water and electrolytes?
- A. Collecting duct
- B. Distal convoluted tubule
- C. Proximal convoluted tubule
- D. Descending limb of Loop of Henle
What is the function of the collecting ducts in the kidney?
- A. Filtration of blood
- B. Transport of urine to the bladder
- C. Final concentration of urine
- D. Regulation of blood pressure
What is the correct order of urine flow through the kidney structures?
- A. Glomerulus → Proximal convoluted tubule → Descending limb → Ascending limb → Distal convoluted tubule → Collecting duct → Minor calyx → Major calyx → Renal pelvis
- B. Proximal convoluted tubule → Descending limb → Glomerulus → Ascending limb → Distal convoluted tubule → Collecting duct → Minor calyx → Major calyx → Renal pelvis
- C. Glomerulus → Descending limb → Ascending limb → Proximal convoluted tubule → Distal convoluted tubule → Collecting duct → Renal pelvis → Minor calyx → Major calyx
- D. Collecting duct → Renal pelvis → Major calyx → Minor calyx → Proximal convoluted tubule → Glomerulus → Ascending limb → Descending limb → Distal convoluted tubule
Which of the following is NOT a component of the renal tubule?
- A. Proximal convoluted tubule
- B. Descending limb of Loop of Henle
- C. Ascending limb of Loop of Henle
- D. Renal pelvis
Which structure in the kidney is responsible for urine formation?
- A. Renal pelvis
- B. Collecting duct
- C. Glomerulus
- D. Renal calyx
What does the renal column contain?
- A. Glomeruli
- B. Renal pyramids
- C. Collecting ducts
- D. Blood vessels and connective tissue
How does urine move from the major calyces to the renal pelvis?
- A. Through the ureter
- B. Via the collecting ducts
- C. By gravitational flow
- D. Through the renal pelvis
What is the primary function of the renal cortex?
- A. Urine concentration
- B. Blood filtration and initial urine formation
- C. Blood pressure regulation
- D. Hormone production
Which vessel carries blood away from the glomerulus?
- A. Efferent arteriole
- B. Afferent arteriole
- C. Renal vein
- D. Peritubular capillaries
Which part of the kidney is involved in concentrating urine?
- A. Renal cortex
- B. Renal medulla
- C. Renal pelvis
- D. Ureter
What type of blood vessels are the peritubular capillaries?
- A. Arteries
- B. Veins
- C. Capillaries
- D. Arterioles
What does the distal convoluted tubule primarily do?
- A. Filtration of blood
- B. Reabsorption of water
- C. Reabsorption of ions and regulation of pH
- D. Concentration of urine

Answer

A

What happens to blood pressure in the glomerulus when the efferent arteriole constricts?
• A. Increases
• B. Decreases
• C. Remains the same
• D. Fluctuates
• Answer: A. Increases

The efferent arteriole carries blood away from the glomerulus after filtration but does not directly collect blood from the peritubular capillaries. Here’s a breakdown:

Efferent Arteriole (B): Transports blood from the glomerulus to the peritubular capillaries or vasa recta. It does not directly collect blood from the peritubular capillaries.
Peritubular Capillaries: These capillaries surround the nephron tubules and are involved in reabsorption and secretion. Blood from the peritubular capillaries then flows into the venules.
Renal Vein (C): Collects blood from the venules, which are the vessels that drain blood from the peritubular capillaries and eventually lead to the renal vein. The renal vein then carries blood away from the kidney to the inferior vena cava.

Therefore, the renal vein (C) is the correct answer as it is the vessel that ultimately collects blood from the peritubular capillaries.

Here are the answers:

C. Renal cortex
B. Urine concentration and transport
A. Minor calyx
C. Afferent arteriole
B. Regulating blood pressure in the glomerulus
A. Renal pelvis
B. Reabsorption and secretion
C. Glomerulus
C. Proximal convoluted tubule
C. Final concentration of urine
A. Glomerulus → Proximal convoluted tubule → Descending limb → Ascending limb → Distal convoluted tubule → Collecting duct → Minor calyx → Major calyx → Renal pelvis
D. Renal pelvis
C. Glomerulus
D. Blood vessels and connective tissue
C. By gravitational flow
B. Blood filtration and initial urine formation
A. Efferent arteriole
B. Renal medulla
C. Capillaries
C. Reabsorption of ions and regulation of pH

Question 16

Q

Explain how urine is produced in the body

Answer

A

Afferent to glomerulus to bowman’s to proximal convoluted where water is reabsorbed and ions too then to ascending loop of henle where water is reabsorbed cuz it is permeable to water making the urine hyperosmotic or consentrated then to descending loop where ions are reabsorbed but not water cuz it is impermeable to water then to distal convoluted where more Reabsorption of ions not water occurs then to collecting duct then to renal papillae then to minor and major calyx then to renal pelvis then to ureter
Here’s a step-by-step process of urine formation involving all the key structures of the kidney:

Blood enters the kidney through the renal artery.
**Blood flows into the afferent arteriole, which supplies blood to the glomerulus.
Glomerulus: Blood is filtered in the glomerulus, a network of capillaries where water, ions, and small molecules are forced into the Bowman’s capsule (part of the nephron).
Bowman’s Capsule: The filtrate (fluid) collected here is known as glomerular filtrate.
5.Efferent Arteriole: After filtration, the blood exits the glomerulus through the efferent arteriole. This vessel carries blood away from the glomerulus and supplies it to the peritubular capillaries or vasa recta.
1. Peritubular Capillaries/Vasa Recta: Surrounding the nephron tubules, these capillaries facilitate the exchange of substances between the blood and the filtrate, aiding in reabsorption and secretion.
Proximal Convoluted Tubule (PCT): Filtrate moves from the Bowman’s capsule into the PCT, where significant reabsorption of water, ions, and nutrients occurs.
Descending Limb of the Loop of Henle: The filtrate then moves into the descending limb, which is permeable to water but not to ions. This segment helps concentrate the urine as water is reabsorbed.
Ascending Limb of the Loop of Henle: Next, the filtrate moves into the ascending limb, which is impermeable to water but actively transports ions (sodium, potassium, chloride) out of the filtrate into the surrounding interstitial fluid.
Distal Convoluted Tubule (DCT): The filtrate then passes through the DCT, where further reabsorption of ions and secretion of substances (like potassium and hydrogen ions) occurs, adjusting the composition of the urine.
Collecting Duct: The filtrate moves into the collecting duct, where final adjustments are made, including the reabsorption of water, to concentrate the urine further.
Renal Papilla: Urine flows from the collecting duct into the renal papillae, which are the tips of the renal pyramids.
Minor Calyx: Urine then drains from the renal papillae into the minor calyces.
Major Calyx: Minor calyces converge to form major calyces.
Renal Pelvis: Major calyces drain into the renal pelvis, a funnel-shaped structure that collects urine from the calyces.
Ureter: Urine exits the renal pelvis and flows into the ureter, which transports it to the bladder for storage.
Bladder: The bladder stores urine until it is excreted from the body.
Urethra: Urine is expelled from the bladder through the urethra during urination.

This sequence describes how blood is filtered, how urine is formed and concentrated, and how it eventually exits the body.

Urine formation in the kidneys is a complex process involving several key steps, occurring in different parts of the nephron. Here’s a simplified explanation:

Location: Glomerulus (in the renal cortex).
Process: Blood enters the kidney through the afferent arteriole and flows into the glomerulus, a network of tiny capillaries. The blood pressure forces water, ions, and small molecules (but not larger proteins or cells) through the glomerular filtration membrane into the Bowman’s capsule to form glomerular filtrate.

Location: Renal Tubule (including the proximal convoluted tubule, Loop of Henle, distal convoluted tubule).
Process:
- Proximal Convoluted Tubule (PCT): Most of the water, sodium, and essential nutrients like glucose and amino acids are reabsorbed from the filtrate back into the bloodstream.
- Loop of Henle:
  - Descending Limb: Permeable to water, allowing water to be reabsorbed into the surrounding tissues, concentrating the filtrate.
  - Ascending Limb: Impermeable to water but actively transports sodium, potassium, and chloride ions out of the filtrate, diluting it.
- Distal Convoluted Tubule (DCT): Further adjusts the filtrate’s composition by reabsorbing sodium and calcium, and secreting additional ions and waste products.

Location: Renal Tubule (primarily in the DCT and collecting duct).
Process: Additional waste products (e.g., hydrogen ions, potassium) and drugs are secreted from the blood into the filtrate, further modifying its composition.

Location: Collecting Ducts and Renal Papillae.
Process:
- Collecting Ducts: The filtrate (now called urine) is further concentrated as water is reabsorbed under the influence of antidiuretic hormone (ADH). The final concentration of urine is determined here.
- Renal Papillae: Urine exits the collecting ducts and drains into the minor calyces, then into the major calyces.

Location: Ureter.
Process: Urine flows from the renal pelvis into the ureter, which transports it to the bladder for storage until it is excreted from the body.

Filtration in the glomerulus creates the initial filtrate.
Reabsorption in the PCT, Loop of Henle, and DCT adjusts the filtrate’s composition.
Secretion in the DCT and collecting ducts adds additional waste to the filtrate.
Concentration in the collecting ducts finalizes the urine composition.
Transport through the ureter to the bladder.

This process ensures that essential substances are retained while waste products and excess substances are eliminated in the urine.

Renal Cortex:
- Location: The outer layer of the kidney.
- Function: Contains the renal corpuscles (glomeruli and Bowman’s capsules) and the proximal and distal convoluted tubules. It is involved in the initial filtration of blood and reabsorption of essential nutrients and water.
Renal Pyramids:
- Location: The triangular structures located within the renal medulla (the inner part of the kidney).
- Function: Contain the collecting ducts and are involved in the concentration of urine. The pyramids collect urine from the nephrons and channel it towards the renal papillae.

Formation and Collection:
- Renal Pyramids: Urine produced in the nephrons flows into the collecting ducts, which converge at the renal papillae located at the tips of the renal pyramids.
- Minor Calyces: Urine from the renal papillae drains into the minor calyces. Each minor calyx collects urine from one renal pyramid.
Joining to Major Calyces:
- Major Calyces: Minor calyces merge to form major calyces. Each major calyx collects urine from multiple minor calyces.
Flow to Renal Pelvis:
- Renal Pelvis: Major calyces converge to form the renal pelvis, which acts as a funnel to channel urine from the major calyces into the ureter.

From Collecting Ducts: Urine flows from the collecting ducts in the renal pyramids into the renal papillae.
Into Minor Calyces: Urine then drains from the renal papillae into the minor calyces.
Into Major Calyces: Minor calyces converge to form major calyces.
Into Renal Pelvis: Major calyces drain into the renal pelvis.
To Ureter: The renal pelvis collects urine and sends it through the ureter to the bladder.

This system ensures that urine is efficiently collected from the nephrons and transported out of the kidney for excretion.

Here’s how the efferent arteriole and peritubular capillaries fit into the process of urine formation:

Location:
- After the Glomerulus: The efferent arteriole exits the glomerulus after the blood has been filtered.
Function:
- Blood Flow Regulation: The efferent arteriole constricts to regulate blood flow and maintain pressure in the glomerulus. This helps in controlling the rate of filtration.
- Pressure Regulation: By adjusting the diameter of the efferent arteriole, the kidney can regulate glomerular filtration rate (GFR).

Location:
- Surrounding the Renal Tubule: The peritubular capillaries are small blood vessels that surround the renal tubules (proximal and distal convoluted tubules) in the renal cortex.
Function:
- Reabsorption: After filtration in the glomerulus, the filtrate (now called tubular fluid) flows through the renal tubules. The peritubular capillaries reabsorb water, nutrients (like glucose and amino acids), and ions (like sodium and potassium) from the tubular fluid back into the bloodstream.
- Secretion: They also allow for the secretion of additional waste products and ions from the blood into the tubular fluid to be excreted in urine.

Filtration: Blood enters the glomerulus via the afferent arteriole. Filtrate is created as blood pressure forces water and small solutes through the filtration membrane into the Bowman’s capsule.
Efferent Arteriole: Blood exits the glomerulus through the efferent arteriole. The constriction of the efferent arteriole helps to maintain glomerular pressure and regulate filtration rate.
Peritubular Capillaries: Surrounding the renal tubules, these capillaries reabsorb substances from the tubular fluid into the blood and secrete additional wastes into the tubular fluid.
Collecting Ducts: The processed filtrate (now urine) moves through the collecting ducts and then to the renal papillae, where it drains into the minor calyces, major calyces, renal pelvis, and eventually into the ureters.

In summary, the efferent arteriole helps regulate the pressure and flow in the glomerulus, while the peritubular capillaries are essential for reabsorbing valuable substances and secreting waste products into the tubular fluid.

Gh Hhh

Question 17

Q

Cumulus oophorius is the stalk that holds the ovum.

Fertilization: occurs in two phases
Phase 1- penetration of corona radiata
Phase 2- penetration of zona pellucida

Lower Mandible: The mandible is the lower jawbone, and it is the only movable bone of the skull.
Upper Mandible (Maxilla): The maxilla refers to the upper jaw, which forms part of the skull and holds the upper teeth. Unlike the mandible, the maxilla is fixed and does not move.

Sphenoid Bone: A complex, butterfly-shaped bone located in the middle of the skull, forming part of the base of the cranium and the sides of the skull. It helps form the orbits of the eyes.
Frontal Bone: The bone that forms the forehead and the upper part of the eye sockets (orbits).
Occipital Bone: The bone at the back and base of the skull, containing the foramen magnum, where the spinal cord passes through to connect to the brain.

Other important bones of the skull include:
- Parietal Bones: Two bones that form the sides and roof of the skull.
- Temporal Bones: Located on the sides of the skull, around the ear region.
- Ethmoid Bone: A small, delicate bone located between the eyes, forming part of the nasal cavity and the orbits.

Axial skeleton is skull,rib cage,vertebrae

The ulna is medial, and the radius is lateral when in the anatomical position (with the palms facing forward).

Biggest fossa-obturator foramen which is located in the pelvis

Bones that make up the axial and appendicular skeleton :

The obturator foramen is the largest foramen in the body. It is located in the pelvis, formed by the pubic and ischial bones, and allows the passage of nerves and blood vessels.

The axial skeleton consists of 80 bones, forming the central axis of the body, and includes:
1. Skull: 22 bones (cranial and facial bones).
2. Hyoid bone: 1 bone in the neck, supporting the tongue.
3. Vertebral Column: 26 bones (including cervical, thoracic, lumbar vertebrae, sacrum, and coccyx).
4. Thoracic Cage:
- Ribs: 24 bones (12 pairs).
- Sternum: 1 bone.

The appendicular skeleton consists of 126 bones, which include the bones of the limbs and the girdles (shoulder and pelvic) that connect them to the axial skeleton.
1. Pectoral (Shoulder) Girdle:
- Clavicle: 2 bones.
- Scapula: 2 bones.

Upper Limbs:
- Humerus: 2 bones.
- Ulna: 2 bones.
- Radius: 2 bones.
- Carpals (Wrist bones): 16 bones.
- Metacarpals (Palm bones): 10 bones.
- Phalanges (Finger bones): 28 bones.
Pelvic Girdle:
- Hip bones (Ilium, Ischium, Pubis): 2 bones.
Lower Limbs:
- Femur: 2 bones.
- Patella: 2 bones.
- Tibia: 2 bones.
- Fibula: 2 bones.
- Tarsals (Ankle bones): 14 bones.
- Metatarsals (Foot bones): 10 bones.
- Phalanges (Toe bones): 28 bones.

Osteoblasts are young bone cells. These are dynamic and very active
. Differentiate into osteocytes and can’t differentiate any further once they become osteocytes.
Osteocytes are mature bone cells.
Osteoclasts resorb worn out bones.

Chrondro is cartilage

Clavicle and scapula (appendicular or axial???)

The clavicle (collarbone) and scapula (shoulder blade) are both part of the appendicular skeleton, not the axial skeleton. The appendicular skeleton consists of the bones of the limbs and girdles (shoulder and pelvic), while the axial skeleton includes the skull, vertebral column, and rib cage.

Ossification can occur in the skull of a baby.

The anterior fontanelle is diamond-shaped, while the posterior fontanelle is triangular-shaped.

C1-7
T1-12
L1-5
S1-5

Atlas and axis
Which has odontoid process?

The axis (C2 vertebra) has the odontoid process (also known as the dens), which is a bony projection that allows the atlas (C1 vertebra) to pivot and rotate the head. The atlas does not have an odontoid process but rather a ring-like structure that supports the skull.

Joints:
Fossa- depression in bones
Foramen- hollow space

Intercalated discs join one fiber to the other in the cardiac muscle.
Position of nucleus in muscles.

Fusiform(have tapered ends but midline is enlarged) or spindle shaped- smooth muscles

Plenty muscles in the face cuz the face has different facial Expressions

Chest muscles- pectoralis muscles major and minor

Sternocleidomastoid in neck

Seatbelt muscle on thigh-sartorious muscle
Ileotibial tract around hips -
Gluteal muscles- 3 of them

Iliotibial Tract (IT Band):

The iliotibial tract (IT band) is a thick band of connective tissue that runs along the outside of the thigh from the hip to the knee. It stabilizes the knee and assists with movements of the hip and thigh.

Gluteal Muscles (3 of Them):

1.	Gluteus Maximus: The largest and most superficial of the gluteal muscles, responsible for extending and rotating the thigh.
2.	Gluteus Medius: Located beneath the gluteus maximus, it is involved in abducting and medially rotating the thigh.
3.	Gluteus Minimus: The smallest and deepest gluteal muscle, also involved in thigh abduction and medial rotation.

Peristalsis can be controlled at a part where skeletal Muscles are. The skeletal muscles are in the upper 1/3rd of the oesophagus

URINARY SYSTEM

Urethra is away from bladder
Ureter- is towards the bladder

Cortex and
Medulla are two main divisions of kidney

Ultrafiltration makes urine come

I’m getting to glomerulus, Afferent has a wider diameter than efferent.
Glomerulus,Proximal, loop of henle, distal convoluted,tubules

•	The afferent arteriole has a wider diameter than the efferent arteriole, allowing more blood to enter the glomerulus and creating high pressure, which helps with filtration.
•	In the nephron:
1.	Glomerulus: A cluster of capillaries that filters blood to form urine.
2.	Proximal Convoluted Tubule (PCT): Reabsorbs water, ions, and nutrients from the filtrate.
3.	Loop of Henle: Concentrates the urine by reabsorbing water and sodium.
4.	Distal Convoluted Tubule (DCT): Further reabsorption and secretion occur here to fine-tune the urine

Spongy tissues in penis:
2 at top and one below.
Corpus spongiousmum and corpora cavernosa of penis and their functions

Spongy Tissues in Penis:

•	The penis contains three spongy tissues:
1.	2 Corpora Cavernosa: These are located at the top (dorsal side) of the penis. They fill with blood during an erection, causing the penis to become rigid.
2.	1 Corpus Spongiosum: Located below the corpora cavernosa, it surrounds the urethra. Unlike the corpora cavernosa, it remains soft during an erection to keep the urethra open for ejaculation.

Functions:

•	Corpus Spongiosum: Protects the urethra and ensures it remains open during an erection for ejaculation.
•	Corpora Cavernosa: Responsible for the rigidity of the penis during an erection by filling with blood.

Body of uterus is made up of muscles and glands. : Muscle Tissue: The main muscle layer is called the myometrium. It consists of smooth muscle fibers that contract during menstruation and childbirth.
2. Glandular Tissue: The inner lining of the uterus is called the endometrium, which contains glandular cells that secrete substances to support implantation and sustain early pregnancy. The endometrium also undergoes cyclical changes during the menstrual cycle.

Semen helps sperm to swim.
Capacitation-spermatozoa are conditioned to help it swim. Epithelial interaction between vagina and sperm stuff

Prostrate adds what fluid???
Seminal vesicles adds what fluid???

The prostate gland adds prostatic fluid to the ejaculate. This fluid is slightly acidic and contains enzymes, including prostate-specific antigen (PSA), that help to liquefy semen after ejaculation and provide nutrients for sperm.
The seminal vesicles add seminal fluid to the ejaculate. This fluid is alkaline and rich in fructose, which provides energy for the sperm, and other substances that help with sperm motility and viability.

Urethra has dual function. Semen and urine

Prostatic urethra is blocked in cancer

Nervous system:

Fight and flight. Parasympathetic or sympathetic?? Ans is sympathetic

Spinal nerves : There are 12 pairs of cranial nerves and 31 pairs of spinal nerves.

Cranial Nerves: These nerves arise from the brain and primarily innervate structures in the head and neck.
Spinal Nerves: These nerves arise from the spinal cord and are categorized into 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal pairs.

Gray matter is butterfly shaped with a central canal and is gray cuz it’s made up of many cell bodies but few axons. So more central processes and few peripheral

White matter has more peripheral processes and less central processes.

Anterior median fissure. Deeper than sulcus
Posterior median sulcus

Afferent enter from back
Efferent are from front
Mixed nerve: cuz it’s made up of sensory and motor

Pseudo polar neuron in afferent in dorsal root ganglion

Here is a summary of your points about spinal nerves and spinal cord anatomy:

Gray Matter:
- Shape: Gray matter is butterfly-shaped or H-shaped in cross-section, with a central canal running through the middle.
- Composition: It is gray due to a high concentration of neuronal cell bodies and fewer myelinated axons. It primarily contains cell bodies and central processes, making it involved in processing and integrating information.
White Matter:
- Composition: White matter surrounds the gray matter and consists mostly of myelinated axons, which provide the pathways for transmitting information between different parts of the nervous system. It has more peripheral processes and fewer central processes.
Anterior Median Fissure:
- Description: A deep groove along the anterior (front) aspect of the spinal cord that separates the two halves of the spinal cord. It is deeper than the posterior median sulcus.
Posterior Median Sulcus:
- Description: A shallow groove along the posterior (back) aspect of the spinal cord that separates the two halves of the spinal cord.
Afferent and Efferent Fibers:
- Afferent Fibers: Sensory neurons that enter the spinal cord through the dorsal (posterior) root.
- Efferent Fibers: Motor neurons that exit the spinal cord through the ventral (anterior) root.
Mixed Nerve:
- Description: A spinal nerve is considered mixed because it contains both sensory (afferent) and motor (efferent) fibers.
Pseudounipolar Neurons:
- Location: Found in the dorsal root ganglion.
- Description: These neurons have a single, short process that splits into two branches—one extending to the periphery and one entering the spinal cord—functioning as afferent (sensory) neurons.

Ependymal cells and choroid plexus produce CSF. The ependymal cells are glial cells.
Astrocytes- blood brain barrier
Satellite cells- structural and nutritional functions

Satellite cells are found in the peripheral nervous system (PNS) and have the following functions:

Structural Function: Satellite cells provide structural support to the neurons in the ganglia (clusters of neuronal cell bodies in the PNS). They help maintain the organization and integrity of the ganglia.
Nutritional Function: They provide metabolic and nutritional support to the neuronal cell bodies by regulating the microenvironment around the neurons. They assist in the exchange of nutrients and waste products between the neurons and the surrounding interstitial fluid.

These functions are crucial for the proper functioning and health of neurons in the PNS. Correct, satellite cells are found only in the peripheral nervous system (PNS). In the central nervous system (CNS), their functions are performed by astrocytes, which provide structural support, regulate the extracellular environment, and offer metabolic support to neurons.

Conducting pathway- conducts air
Respiratory pathway does exchange

Intercostal and other muscle sim ribs and in exclamation and inhalation

Primary filtration occurs from pharynx -larynx to the trachea

Blood air barrier- pneumocyste type I cells also called alveolar cells
Alveolar lining and endothelium of capillaries

The blood-air barrier (also known as the air-blood barrier) is the thin barrier that separates the air in the alveoli from the blood in the capillaries, allowing for efficient gas exchange. It consists of the following components:

Type I Pneumocytes (Alveolar Type I Cells):
- Description: These are thin, squamous epithelial cells that line the alveolar walls. They cover the majority of the surface area of the alveoli.
- Function: They provide a large surface area for gas exchange and form the primary component of the blood-air barrier.
Alveolar Lining:
- Description: The lining of the alveoli is composed of the type I pneumocytes, which create a thin surface for the diffusion of gases.
Endothelium of Capillaries:
- Description: The endothelial cells that line the capillaries are thin and closely apposed to the type I pneumocytes. They form the inner lining of the blood vessels.

Alveolar Epithelium: Consists of type I pneumocytes.
Basement Membrane of Alveolar Epithelium: A thin layer of extracellular matrix that separates the alveolar epithelium from the capillary endothelium.
Capillary Endothelium: The endothelial cells lining the capillaries.
Basement Membrane of Capillary Endothelium: Sometimes fused with the alveolar basement membrane, further reducing the distance for gas diffusion.

This barrier is extremely thin to facilitate the rapid exchange of oxygen and carbon dioxide between the air in the alveoli and the blood in the capillaries.

INTEGUMENTARY SYSTEM:
Parts of skin
Subcutaneous tissue isn’t part of integumentary system.

Hair follicles and sebaceous glands

Layers of epidermis;
Stratum cornels I’m

Stratum basaliae cells ah epotmetial to regeneration to feed cells that are becoming aged. Aged cells are at the top and new ones are below or at the base.

Keratin is in the stratum corneum

Thin skin- palm and sole of feet
Thick- general skin(you don’t really find hair) have stratum lucidum but this type of stratum isn’t in the thin skin

Sensory receptors in the skin.

Here’s a detailed overview of the skin and its components:

Epidermis: The outermost layer of the skin, composed of stratified squamous epithelium. It includes the following layers from outermost to innermost:
- Stratum Corneum: The outermost layer, consisting of dead, flattened keratinized cells. This layer provides a tough, protective barrier.
- Stratum Lucidum: A thin, clear layer found only in thick skin (palms and soles). It lies just beneath the stratum corneum.
- Stratum Granulosum: Contains keratinocytes that produce granules of keratohyalin and lamellar bodies, contributing to the waterproof barrier of the skin.
- Stratum Spinosum: Provides strength and flexibility to the skin. It contains spiny-shaped keratinocytes connected by desmosomes.
- Stratum Basale (Basal Layer): The deepest layer, consisting of a single row of columnar or cuboidal cells that divide and produce new keratinocytes. It includes melanocytes (pigment-producing cells) and Merkel cells (sensory receptors).
Dermis: The layer beneath the epidermis, composed of connective tissue. It contains:
- Papillary Dermis: The upper layer with loose connective tissue and dermal papillae that interlock with the epidermis.
- Reticular Dermis: The deeper layer with dense irregular connective tissue that provides strength and elasticity to the skin.
Subcutaneous Tissue (Hypodermis): Although not technically part of the integumentary system, it is the layer beneath the dermis, consisting of loose connective tissue and fat that insulates and cushions the body.

Hair Follicles: Structures that produce hair. They are located in the dermis and have an associated sebaceous gland.
Sebaceous Glands: Glands that secrete sebum (oil) into the hair follicles, lubricating the skin and hair.

Keratin: A protein found in the stratum corneum that provides strength and waterproofing to the skin.
Thin Skin: Found over most of the body, including the face. It lacks a stratum lucidum and has fewer layers in the stratum corneum.
Thick Skin: Found on the palms of the hands and soles of the feet. It includes a stratum lucidum and has a thicker stratum corneum.

Mechanoreceptors:
- Meissner’s Corpuscles: Detect light touch and vibrations; found in the dermal papillae of glabrous skin.
- Pacinian Corpuscles: Detect deep pressure and vibrations; located in the deep dermis and subcutaneous tissue.
- Ruffini Endings: Detect stretch and pressure; located in the deep dermis.
Thermoreceptors:
- Krause End Bulbs: Detect cold temperatures.
Nociceptors:
- Pain Receptors: Detect tissue damage and noxious stimuli.

The skin’s structure and its sensory receptors work together to protect the body and provide information about the external environment.

Question 18

Q

Urinary system

Answer

A

URINARY SYSTEM

Urethra is away from bladder
Ureter- is towards the bladder

Cortex and
Medulla are two main divisions of kidney

Ultrafiltration makes urine come

I’m getting to glomerulus, Afferent has a wider diameter than efferent.
Glomerulus,Proximal, loop of henle, distal convoluted,tubules

•	The afferent arteriole has a wider diameter than the efferent arteriole, allowing more blood to enter the glomerulus and creating high pressure, which helps with filtration.
•	In the nephron:
1.	Glomerulus: A cluster of capillaries that filters blood to form urine.
2.	Proximal Convoluted Tubule (PCT): Reabsorbs water, ions, and nutrients from the filtrate.
3.	Loop of Henle: Concentrates the urine by reabsorbing water and sodium.
4.	Distal Convoluted Tubule (DCT): Further reabsorption and secretion occur here to fine-tune the urine

Spongy tissues in penis:
2 at top and one below.
Corpus spongiousmum and corpora cavernosa of penis and their functions

Spongy Tissues in Penis:

•	The penis contains three spongy tissues:
1.	2 Corpora Cavernosa: These are located at the top (dorsal side) of the penis. They fill with blood during an erection, causing the penis to become rigid.
2.	1 Corpus Spongiosum: Located below the corpora cavernosa, it surrounds the urethra. Unlike the corpora cavernosa, it remains soft during an erection to keep the urethra open for ejaculation.

Functions:

•	Corpus Spongiosum: Protects the urethra and ensures it remains open during an erection for ejaculation.
•	Corpora Cavernosa: Responsible for the rigidity of the penis during an erection by filling with blood.

Body of uterus is made up of muscles and glands. : Muscle Tissue: The main muscle layer is called the myometrium. It consists of smooth muscle fibers that contract during menstruation and childbirth.
2. Glandular Tissue: The inner lining of the uterus is called the endometrium, which contains glandular cells that secrete substances to support implantation and sustain early pregnancy. The endometrium also undergoes cyclical changes during the menstrual cycle.

Semen helps sperm to swim.
Capacitation-spermatozoa are conditioned to help it swim. Epithelial interaction between vagina and sperm stuff

Prostrate adds what fluid???
Seminal vesicles adds what fluid???

The prostate gland adds prostatic fluid to the ejaculate. This fluid is slightly acidic and contains enzymes, including prostate-specific antigen (PSA), that help to liquefy semen after ejaculation and provide nutrients for sperm.
The seminal vesicles add seminal fluid to the ejaculate. This fluid is alkaline and rich in fructose, which provides energy for the sperm, and other substances that help with sperm motility and viability.

Urethra has dual function. Semen and urine

Prostatic urethra is blocked in cancer

Question 19

Q

CVS-
Types of capillaries : fenestrated (have holes in them. Seen in glomerulus of Kidney) and non fenestrated
Types of vein- large vein,medium
Sized vein and venules. Have tunica wrapped around them. Know the parts. Tunica media is composed of smooth muscles. Elastic fibers in veins or vessels
Types of artery’s -elastic artery,muscular artery,arteriole. Difference in sizes of lumen and tunicas

Another name for elastic artery is large artery
Another name for
Medium size artery is muscular artery

Right ventricle to pulmonary trunk into the lungs.

Systemic and pulmonary circulation

Capillary bed is where exchange goes on.

Smooth msucles in arteries and veins. Difference in tunica of arteries and veins.
Blood isn’t moving at high pressure so there is baxkflow of blood if the valves don’t work

Here’s a more detailed overview of the different types of blood vessels, including their structures and functions:

Fenestrated Capillaries:
- Structure: Have pores (fenestrae) in their endothelial lining.
- Locations: Found in areas requiring rapid exchange of small molecules, such as the glomeruli of the kidneys, intestines, and endocrine glands.
Non-Fenestrated Capillaries:
- Structure: Have a continuous endothelial lining with no pores.
- Locations: Found in most tissues, including muscle, skin, and the blood-brain barrier.

Large Veins:
- Examples: Superior and inferior vena cava.
- Structure: Have a larger lumen and more developed tunica adventitia (outer layer). Tunica media is thinner with less smooth muscle compared to arteries.
Medium-Sized Veins:
- Examples: Femoral vein, brachial vein.
- Structure: Have a smaller lumen compared to large veins, but still contain valves to prevent backflow. Tunica media is relatively thin, and tunica adventitia is prominent.
Venules:
- Structure: Small veins that receive blood from capillaries. They have a very thin tunica media and tunica adventitia.

Elastic Arteries:
- Other Name: Large arteries.
- Examples: Aorta, pulmonary arteries.
- Structure: Have a large lumen and a thick tunica intima, tunica media (rich in elastic fibers), and tunica adventitia. The elastic fibers allow these arteries to stretch and recoil to accommodate the high pressure of blood flow.
Muscular Arteries:
- Other Name: Medium-sized arteries.
- Examples: Femoral artery, radial artery.
- Structure: Have a smaller lumen compared to elastic arteries and a thicker tunica media composed mainly of smooth muscle fibers. They regulate blood flow to specific organs and tissues by constriction and dilation.
Arterioles:
- Structure: Smallest arteries leading to capillaries. They have a very thin tunica intima and a thin tunica media with a few layers of smooth muscle. They play a crucial role in regulating blood flow and blood pressure.

Tunica Intima: The innermost layer, consisting of endothelial cells. It provides a smooth lining for blood flow.
Tunica Media: The middle layer, consisting of smooth muscle and elastic fibers. It regulates the diameter of the vessel and blood pressure.
Tunica Adventitia: The outer layer, consisting of connective tissue that provides structural support and elasticity.

Arteries: Have more smooth muscle in the tunica media, allowing them to handle higher pressure and regulate blood flow.
Veins: Have less smooth muscle compared to arteries and rely on valves to prevent backflow and assist with venous return to the heart.

Function: Sites of nutrient, gas, and waste exchange between blood and tissues.

Veins: Blood in veins is under lower pressure. Valves help prevent backflow and ensure one-way blood flow towards the heart. If valves are defective, it can lead to conditions like varicose veins.

Understanding these aspects helps in comprehending how the circulatory system functions to deliver blood efficiently throughout the body.

The tunicas of arteries and veins differ primarily in thickness and composition to accommodate their different functions:

Arteries: Thicker, with a more prominent internal elastic lamina (elastic tissue), which provides strength and elasticity to withstand high blood pressure.
Veins: Thinner, with fewer elastic fibers and no prominent internal elastic lamina. Veins rely more on valves and external pressure to move blood.

Arteries: Much thicker in arteries, especially in muscular arteries, containing many layers of smooth muscle. This allows arteries to maintain blood pressure and control blood flow through vasoconstriction and vasodilation.
Veins: Much thinner, with fewer smooth muscle cells. Veins do not need to handle high pressure, so the tunica media is less developed.

Arteries: Thinner than in veins, but contains connective tissue, nerves, and smaller blood vessels (vasa vasorum) that nourish the artery wall.
Veins: Thicker in veins, providing structural support, especially in large veins. It also contains vasa vasorum, but the thicker adventitia helps prevent overdistension since veins often deal with low-pressure, high-volume blood flow.

Arteries have a thicker tunica media to handle the higher pressure of blood flowing from the heart.
Veins have a thicker tunica adventitia and thinner media since they carry blood back to the heart at lower pressure and need more structural support. Veins also often have valves to prevent backflow, which are absent in arteries.

Low Pressure: Unlike arteries, veins carry blood back to the heart at lower pressure. Structural support helps prevent collapse under these lower pressures.
2. High Volume: Veins contain a larger volume of blood than arteries. The walls need to be sturdy enough to accommodate this volume without distending excessively.
3. Preventing Backflow: The structural integrity of veins, particularly the tunica adventitia, helps maintain the shape of the vessel and supports the function of valves that prevent backflow of blood, especially in the extremities.
4. Movement and Compression: Veins often run close to muscles and are subject to external pressure from surrounding tissues. Structural support helps them maintain their shape and function even when compressed.

Question: Which layer of the heart is responsible for its contraction?

Possible Answers:
- a) Endocardium: This is the innermost layer of the heart, lining the chambers and valves. It provides a smooth surface for blood flow but does not contract.

b) Epicardium: This is the outer layer of the heart, which is also known as the visceral layer of the pericardium. It serves as a protective layer but does not contribute to contraction.
c) Myocardium: This is the thick middle layer of the heart composed of cardiac muscle. It is responsible for the heart’s contractions, allowing it to pump blood throughout the body. The myocardium varies in thickness depending on the heart chamber; it’s thickest in the left ventricle.
d) Pericardium: This is not a layer of the heart itself but rather a fibrous sac that surrounds and protects the heart. It provides structural support and helps prevent overexpansion.

Correct Answer: c) Myocardium

Endocardium:
- Innermost layer lining the heart chambers and valves.
- Composed of endothelial cells and connective tissue.
- Smooth surface reduces friction as blood flows through the heart.
Myocardium:
- Middle layer composed of cardiac muscle tissue.
- Responsible for the contraction of the heart.
- Thickness varies: thickest in the left ventricle to pump blood throughout the body, thinner in the right ventricle.
Epicardium:
- Outermost layer, also known as the visceral layer of the pericardium.
- Composed of connective tissue and fat, providing protection.
- Contains blood vessels that supply the heart muscle.
Pericardium:
- A double-walled sac surrounding the heart.
- Composed of two layers: the outer fibrous layer and the inner serous layer (which has a visceral and parietal layer).
- Protects the heart and anchors it to surrounding structures, reducing friction during heartbeats.

The semilunar valves consist of two valves located at the exits of the ventricles:
- Pulmonary Semilunar Valve: Located between the right ventricle and the pulmonary artery, preventing backflow of blood into the right ventricle after contraction.
- Aortic Semilunar Valve: Located between the left ventricle and the aorta, preventing backflow into the left ventricle.

Both valves ensure one-way blood flow out of the heart and prevent backflow during relaxation.

If you have more questions or need further clarification, feel free to ask!

Yes, there are four main valves in the heart:

Mitral Valve (Bicuspid Valve):
- Located between the left atrium and the left ventricle.
- Allows blood to flow from the atrium to the ventricle and prevents backflow.
Tricuspid Valve:
- Located between the right atrium and the right ventricle.
- Functions similarly to the mitral valve, allowing blood to flow into the ventricle and preventing backflow.
Pulmonary Semilunar Valve:
- Located between the right ventricle and the pulmonary artery.
- Prevents backflow of blood into the right ventricle after it has been pumped into the pulmonary artery.
Aortic Semilunar Valve:
- Located between the left ventricle and the aorta.
- Prevents backflow of blood into the left ventricle after it has been ejected into the aorta.

These four valves work together to ensure unidirectional blood flow through the heart and prevent any backflow during the cardiac cycle.

Question 20

Q

Interventricular Septum:
- The interventricular septum is the thick muscular wall that separates the left and right ventricles of the heart.
- It prevents the mixing of oxygenated blood in the left ventricle with deoxygenated blood in the right ventricle.
- The septum plays a crucial role in the heart’s pumping function, as it helps maintain pressure differences between the two ventricles.

Coronary Sulcus:
- The coronary sulcus, also known as the atrioventricular (AV) groove, is a groove on the surface of the heart that separates the atria from the ventricles.
- It encircles the heart and contains the coronary arteries and veins that supply blood to the heart muscle itself.
- The coronary sulcus helps to define the borders of the heart chambers and provides a pathway for blood vessels.

The coronary veins drain deoxygenated blood from the heart muscle back to the right atrium.
The primary vessel involved is the coronary sinus, which collects blood from various cardiac veins and empties directly into the right atrium.

The internal carotid arteries and the vertebral arteries supply blood to the brain.
The internal carotid arteries branch from the common carotid arteries and enter the skull to supply the anterior and middle parts of the brain.
The vertebral arteries, which branch from the subclavian arteries, travel up the neck and join to form the basilar artery, supplying the posterior part of the brain.

Question: What part of the heart initiates the electrical impulse for contraction?

Possible Answers:
- a) Atrioventricular (AV) node: The AV node receives impulses from the sinoatrial (SA) node and helps regulate the timing of contractions between the atria and ventricles. It serves as a gatekeeper to slow down the electrical signal before it passes to the ventricles, ensuring the atria contract first.

b) Sinoatrial (SA) node: This is the primary pacemaker of the heart, located in the right atrium. It generates electrical impulses that initiate each heartbeat and set the rhythm of the heart. The SA node controls the heart rate and triggers atrial contraction.
c) Bundle of His: This structure transmits electrical impulses from the AV node to the ventricles via the right and left bundle branches. It is crucial for coordinating the timing of ventricular contraction but does not initiate the heartbeat.
d) Purkinje fibers: These fibers distribute the electrical impulses throughout the ventricles, ensuring coordinated contraction. They are the final pathway for the electrical signal, allowing the ventricles to contract efficiently.

Correct Answer: b) Sinoatrial node

If you have further questions or need more details, feel free to ask!

Interventricular Septum:
- The interventricular septum separates the left and right ventricles, not the atria from the ventricles.

Atrial Septum:
- The interatrial septum is the wall that separates the left and right atria.

Coronary Sulcus:
- The coronary sulcus separates the atria from the ventricles. It encircles the heart and contains coronary blood vessels, but it does not serve to separate the chambers themselves.

Bundle of His:
- Also known as the atrioventricular bundle, it is a collection of heart muscle cells specialized for electrical conduction.
- It originates from the AV node and runs along the interventricular septum, splitting into the right and left bundle branches.
- The Bundle of His serves as a pathway to transmit impulses from the atria to the ventricles.

Purkinje Fibers:
- These are specialized conductive fibers that branch off from the right and left bundle branches and spread throughout the ventricular myocardium.
- They facilitate the rapid conduction of electrical impulses to the ventricular muscle, ensuring a coordinated contraction of the ventricles.
- Purkinje fibers are more abundant and larger than the fibers of the Bundle of His.

Interventricular Septum: Separates the ventricles.
Interatrial Septum: Separates the atria.
Coronary Sulcus: Encircles the heart, marking the boundary between atria and ventricles.
Bundle of His: Conducts impulses from the AV node to the ventricles.
Purkinje Fibers: Distribute impulses throughout the ventricles for coordinated contraction.

If you have any more questions or need further details, let me know!

The bundle of His is a heart muscle that takes part in electrical conduction in the heart. Purkinje fibres are branched fibres that carry the electrical impulse to the ventricles. It is branched into both the right and left bundle branches of the heart, and runs through the interventricular septum.
https://byjus.c

Answer

A

The heart consists of an electrical conduction system that helps contract the heart muscles. The electrical signals generated by the pacemaker travel through different structures in the heart to cause contraction. The electrical system consists of an atrioventricular node, Purkinje fibres, a bundle of His, a sinoatrial node, and three bundle branches.

Purkinje fibres are located in the heart’s ventricular walls, below the endocardium, in a space called the subendocardium.

Purkinje fibres can also act as alternative pacemakers when the primary pacemaker (the SA node) fails to perform. Though it creates impulses at a lower rate than the SA node, it can save the heart when all the other pacemakers fail.

The bundle of His is a heart muscle that takes part in electrical conduction in the heart. It is branched into both the right and left bundle branches of the heart, and runs through the interventricular septum. It receives electrical impulses from the SA node and transmits them to the fascicular bundles. It helps in transmitting electrical impulse from the SA node to the ventricles.
Purkinje fibres are branched fibres that carry the electrical impulse to the ventricles. i s present in the ventricular walls of the heart. receives electrical impulses from the fascicular bundles and transmits them to the ventricles. It causes contraction of the heart muscles that ejects the blood out into the circulation

The electrical impulse first starts from the SA node and is transmitted to the bundle of His first, followed by Purkinje fibres.

SA mode to AV node to bundle of His to purkinje fibers to contraction of ventricles

Sinoatrial (SA) Node:
• Located in the right atrium, it generates the electrical impulse that initiates the heartbeat.
2. Atrioventricular (AV) Node:
• Receives the impulse from the SA node and briefly delays it to allow the atria to contract and empty blood into the ventricles.
The atrioventricular (AV) node is located in the right atrium of the heart, specifically at the junction between the atria and ventricles. It is situated near the interatrial septum, close to the opening of the coronary sinus.
3. Bundle of His:
• Transmits the electrical impulse from the AV node down the interventricular septum. It splits into right and left bundle branches.
4. Purkinje Fibers:
• Branch from the bundle branches and spread throughout the ventricular myocardium. They conduct the impulse rapidly, triggering coordinated contraction of the ventricles.
5. Contraction of Ventricles:
• The ventricles contract forcefully to pump blood to the lungs and the rest of the body.

Question 21

Q

The diaphragm is the primary muscle responsible for breathing (inhalation). While intercostal muscles assist in expanding and contracting the rib cage, they are not the main driver of the breathing process.

Question 9 Explanation:

•	The pleura is a double-layered membrane surrounding the lungs. The parietal pleura lines the thoracic cavity, while the visceral pleura covers the lungs themselves.

Upper and Lower Respiratory Tract

•	The upper respiratory tract ends at the larynx, while the lower respiratory tract begins at the trachea.

Conducting Pathway:
- Function: Conducts air from the external environment to the lungs.
- Components: Includes the nose, pharynx, larynx, trachea, bronchi, and bronchioles.
- Role: Filters, warms, and moistens the air before it reaches the respiratory zone.

Respiratory Pathway:
- Function: Site of gas exchange.
- Components: Includes the respiratory bronchioles, alveolar ducts, and alveoli.
- Role: Facilitates the exchange of oxygen and carbon dioxide between the air and blood.

Intercostal Muscles: Located between the ribs; assist in breathing by changing the volume of the thoracic cavity.
Inhalation: Diaphragm contracts and intercostal muscles expand the rib cage.
Exhalation: Muscles relax, decreasing the thoracic cavity volume.

Occurs: From the pharynx through the larynx to the trachea.
Role: Removes particulates and pathogens from the air before it reaches the lungs.

The blood-air barrier is essential for efficient gas exchange, composed of:

Type I Pneumocytes (Alveolar Type I Cells):
- Structure: Thin, squamous cells covering alveoli.
- Function: Provide a large surface area for gas exchange.
Alveolar Lining:
- Composed primarily of type I pneumocytes, facilitating gas diffusion.
Endothelium of Capillaries:
- Structure: Thin endothelial cells lining capillaries.
- Function: Allow for close contact with alveolar cells, enhancing gas exchange efficiency.

Alveolar Epithelium: Made up of type I pneumocytes.
Basement Membrane of Alveolar Epithelium: Thin layer separating alveoli from capillaries.
Capillary Endothelium: Thin layer that lines blood vessels, allowing for rapid diffusion.
Basement Membrane of Capillary Endothelium: Often fused with the alveolar membrane, minimizing diffusion distance.

This barrier’s thinness is crucial for rapid oxygen and carbon dioxide exchange between alveolar air and blood. If you have more questions or need further information, feel free to ask!

Which part of the respiratory system is responsible for the production of mucus?
a) Alveoli
b) Trachea
c) Bronchioles
d) Nasal cavity

Answer

A

Which part of the respiratory system is responsible for the production of mucus?
a) Alveoli
b) Trachea
c) Bronchioles
d) Nasal cavity
Answer: d) Nasal cavity

Pulmonary surfactant reduces surface tension in alveoli and prevents over expansion of the lungs.

Question 22

Q

Let’s break down the processes of inhalation and exhalation, including the roles of the external and internal intercostal muscles, as well as the diaphragm:

Diaphragm:
- The diaphragm is the primary muscle responsible for breathing. During inhalation, the diaphragm contracts and flattens, which increases the volume of the thoracic cavity (the space where your lungs are located).
External Intercostal Muscles:
- These muscles are located between the ribs. When you inhale, the external intercostal muscles contract, lifting the ribcage up and out. This also increases the volume of the thoracic cavity.
Mechanism:
- As the thoracic cavity volume increases, the pressure inside the lungs (intrapulmonary pressure) drops below the pressure of the outside air (atmospheric pressure), and air rushes into the lungs.

Passive Exhalation (Normal Breathing):
- In normal, quiet breathing, exhalation is passive, meaning it doesn’t require muscle contraction.
- When the diaphragm and external intercostal muscles relax, the thoracic cavity returns to its original size due to the elastic recoil of the lungs and chest wall. This decreases lung volume, increasing intrapulmonary pressure, causing air to flow out of the lungs.
Forced Exhalation (During Exercise or Heavy Breathing):
- During forced exhalation, muscle contraction is required.
- Internal Intercostal Muscles: These muscles are located deeper than the external intercostals and act to pull the ribcage down and in, reducing the volume of the thoracic cavity.
- Abdominal Muscles: The abdominal muscles contract to push the diaphragm further upwards, helping to force more air out of the lungs.
Mechanism:
- By reducing the thoracic cavity volume actively (with the internal intercostals and abdominal muscles), pressure inside the lungs increases and air is forced out more quickly and forcefully than during passive exhalation.

Inhalation (active):
- Diaphragm contracts (flattens).
- External intercostal muscles contract (lift ribs).
- This increases thoracic cavity volume, drawing air into the lungs.
Exhalation (normal, passive):
- Diaphragm and external intercostals relax.
- The lungs and chest wall recoil, decreasing thoracic cavity volume, causing air to be pushed out.
Forced Exhalation (active):
- Internal intercostal muscles contract (lower ribs).
- Abdominal muscles contract (push diaphragm up).
- This actively reduces the thoracic cavity volume, forcing more air out.

Air moves in and out of the lungs due to differences in pressure between the thoracic cavity (chest) and the outside atmosphere.

1.	Boyle’s Law:
•	This law states that at a constant temperature, pressure and volume are inversely related. So, if you increase the volume of a container (like the thoracic cavity), the pressure inside it decreases. If you decrease the volume, the pressure increases.
2.	Inhalation (Inspiration):
•	During inhalation, the diaphragm contracts and flattens, and the external intercostal muscles contract, lifting the ribcage outward and upward. This increases the volume of the thoracic cavity.
•	As the volume of the thoracic cavity increases, the pressure inside the lungs (intrapulmonary pressure) drops below the pressure of the air outside the body (atmospheric pressure).
•	This creates a negative pressure (lower pressure inside than outside), and because air moves from an area of higher pressure to lower pressure, air flows into the lungs until the pressures equalize.
3.	Exhalation (Expiration):
•	In normal, passive exhalation, the diaphragm and external intercostal muscles relax. This decreases the volume of the thoracic cavity, increasing the intrapulmonary pressure above the outside atmospheric pressure.
•	As a result, air moves out of the lungs to balance the pressure.
•	During forced exhalation, the internal intercostal muscles and abdominal muscles contract, further reducing the thoracic cavity volume, increasing the pressure, and pushing out air more forcefully.

Summary of Pressure Changes

•	Inhalation: Thoracic cavity volume increases → Intrapulmonary pressure drops → Air flows in (due to lower pressure in the lungs compared to outside).
•	Exhalation: Thoracic cavity volume decreases → Intrapulmonary pressure increases → Air flows out (due to higher pressure in the lungs compared to outside).

Answer

A

So internal intercostal is only used during exhalation and external intercostal is only for inhalation

Yes, that’s correct for normal breathing.

External Intercostal Muscles:
- Function: Help with inhalation.
- How: They contract and lift the ribs up and out, increasing the size of the thoracic cavity, which decreases pressure in the lungs, allowing air to flow in.
- When: Active during inhalation.
Internal Intercostal Muscles:
- Function: Help with forced exhalation.
- How: They contract and pull the ribs down and inward, decreasing the size of the thoracic cavity, which increases pressure in the lungs, pushing more air out.
- When: Active primarily during forced exhalation (e.g., during exercise or heavy breathing). They are not used during normal, passive exhalation.

In normal, quiet breathing:
- Inhalation is an active process involving the external intercostal muscles and diaphragm.
- Exhalation is typically a passive process, relying on the relaxation of the diaphragm and external intercostals, without requiring internal intercostals unless you are forcing exhalation (e.g., blowing out air or during intense exercise).

Does this help clarify?

Question 23

Q

Type I Pneumocytes (Alveolar Type I Cells) Summary:

1.	Primary Function: Responsible for gas exchange between the alveoli and blood, facilitating the diffusion of oxygen and carbon dioxide.
2.	Structure: Thin and flat morphology, maximizing surface area and minimizing the barrier for diffusion.
3.	Barrier Integrity: Contribute to the alveolar-capillary barrier, preventing fluid leakage into the alveoli.
4.	Secretion: Secrete factors that support lung function and provide protection against pathogens.

Which of the following is the smallest airway in the respiratory system?

a) Bronchi
b) Bronchioles
c) Trachea
d) Alveoli

Which structure is responsible for producing mucus in the respiratory system?

a) Alveoli
b) Goblet cells
c) Cilia
d) Type II pneumocytes

What is the primary function of the respiratory mucosa?

a) Gas exchange
b) Filtration and humidification of air
c) Sound production
d) Oxygen transport
Which structure is located at the bifurcation of the trachea and serves as a point where air divides into the right and left bronchi?

a) Carina
b) Larynx
c) Pharynx
d) Mediastinum

What is the role of Type II pneumocytes in the alveoli?

a) To facilitate gas exchange
b) To produce surfactant
c) To trap foreign particles
d) To provide structural support
Which part of the brain regulates the rhythm of breathing?

a) Cerebellum
b) Medulla oblongata
c) Thalamus
d) Pons

Answer

A

Which of the following is the smallest airway in the respiratory system?

a) Bronchi
b) Bronchioles
c) Trachea
d) Alveoli

Answer: b) Bronchioles

Which structure is responsible for producing mucus in the respiratory system?

a) Alveoli
b) Goblet cells
c) Cilia
d) Type II pneumocytes

Answer: b) Goblet cells

•	Goblet cells are specialized epithelial cells that produce mucus, helping to trap particles and pathogens.

What is the primary function of the respiratory mucosa?

a) Gas exchange
b) Filtration and humidification of air
c) Sound production
d) Oxygen transport

Answer: b) Filtration and humidification of air

Which structure is located at the bifurcation of the trachea and serves as a point where air divides into the right and left bronchi?

a) Carina
b) Larynx
c) Pharynx
d) Mediastinum

Answer: a) Carina

•	The carina is the ridge at the base of the trachea that indicates where it splits into the right and left bronchi.

What is the role of Type II pneumocytes in the alveoli?

a) To facilitate gas exchange
b) To produce surfactant
c) To trap foreign particles
d) To provide structural support

Answer: b) To produce surfactant

Which part of the brain regulates the rhythm of breathing?

a) Cerebellum
b) Medulla oblongata
c) Thalamus
d) Pons

Answer: b) Medulla oblongata

Question 24

Q

Upper Respiratory Tract:
- Nasal Cavity:
  - Structure: Divided into right and left halves by the nasal septum; contains nasal conchae (turbinates) that increase surface area for air contact.
  - Functions: Filters particles using mucus and cilia, warms and humidifies inhaled air, and contains olfactory receptors for smell.
- Pharynx:
  - Nasopharynx: Located behind the nasal cavity; contains adenoids (pharyngeal tonsils) that help trap pathogens.
  - Oropharynx: Located behind the oral cavity; serves as a passage for air and food.
  - Laryngopharynx: The region where the pharynx splits into the esophagus and larynx.
- Larynx:
  - Structure: Composed of cartilage (thyroid, cricoid, and epiglottis) and vocal cords.
  - Functions: Protects the trachea from food aspiration, regulates airflow, and produces sound through vocal cord vibration.
Lower Respiratory Tract:
- Trachea:
  - Structure: A tube approximately 10-12 cm long, reinforced with C-shaped cartilage rings to prevent collapse.
  - Lining: Ciliated pseudostratified columnar epithelium with mucus-secreting goblet cells to trap debris.
- Bronchi:
  - Primary Bronchi: The left and right bronchi enter the lungs at the hilum; the right bronchus is wider and more vertical, making it a common site for aspirated objects.
  - Secondary and Tertiary Bronchi: Branch into smaller bronchi within each lung, leading to bronchioles.
- Bronchioles:
  - Structure: Smaller airways without cartilage; surrounded by smooth muscle that can constrict or dilate to regulate airflow.
  - Terminal Bronchioles: Lead to respiratory bronchioles, which contain some alveoli.
Lungs:
- Lobes:
  - Right Lung: Divided into upper, middle, and lower lobes.
  - Left Lung: Divided into upper and lower lobes, with a cardiac notch to accommodate the heart.
- Alveoli:
  - Structure: Approximately 300 million alveoli in healthy lungs, providing a vast surface area (~70 square meters) for gas exchange.
  - Type I Pneumocytes: Facilitate gas exchange.
  - Type II Pneumocytes: Produce surfactant to reduce surface tension and prevent alveolar collapse.
Pleura:
- Parietal Pleura: Adheres to the thoracic wall, diaphragm, and mediastinum.
- Visceral Pleura: Covers the lungs closely, allowing for smooth movement during breathing.
- Pleural Cavity: The negative pressure in the pleural cavity helps keep the lungs inflated.
Muscles of Respiration:
- Diaphragm: The main muscle of inspiration; when contracted, it flattens, increasing thoracic cavity volume and drawing air into the lungs.
- Intercostal Muscles:
  - External Intercostals: Elevate the ribs during inhalation, increasing the thoracic cavity volume.
  - Internal Intercostals: Mainly active during forced exhalation, pulling the ribs downward and inward.
Respiratory Centers:
- Medulla Oblongata: Contains the rhythmicity center that generates the basic rhythm of breathing.
- Pons: Modulates the rhythm and smoothens transitions between inhalation and exhalation.
Additional Structures:
- Sinuses: Air-filled cavities (frontal, maxillary, ethmoid, sphenoid) that reduce skull weight, humidify air, and enhance voice resonance.
- Mucociliary Escalator: A defense mechanism involving cilia that move mucus upward to the pharynx for expulsion.
Vascular Supply:
- Pulmonary Arteries: Carry deoxygenated blood from the heart to the lungs for gas exchange.
- Pulmonary Veins: Return oxygenated blood from the lungs to the heart.
- Bronchial Arteries: Supply oxygenated blood to lung tissues.

The respiratory system’s complex anatomy is finely tuned to facilitate efficient gas exchange, protect against pathogens, and ensure proper airflow regulation. Each component plays a vital role in maintaining respiratory health and function. If you have further questions or need more details on specific aspects, feel free to ask!

Answer

A

The macrophages in the alveoli are called alveolar macrophages. They play a crucial role in the immune defense of the lungs by engulfing and digesting pathogens, debris, and foreign particles that enter the respiratory system.

The hilum is a specific area on the surface of an organ where blood vessels, nerves, and other structures enter and exit. In the context of the lungs:

Location: The hilum is located on the medial (inner) side of each lung.
Structures: It contains the following important components:
- Bronchi: The main bronchi (left and right) enter the lungs at the hilum.
- Pulmonary Arteries: Carry deoxygenated blood from the heart to the lungs.
- Pulmonary Veins: Return oxygenated blood from the lungs to the heart.
- Lymphatic Vessels: Drain lymph from the lungs.
- Nerves: Innervate the lung tissues.

The hilum serves as the point of entry and exit for critical structures that facilitate lung function, including gas exchange and blood circulation. It’s an essential anatomical feature in both the lungs and other organs, such as the kidneys.

What is the primary purpose of the pleural cavity?
A) To produce mucus
B) To facilitate gas exchange
C) To reduce friction during breathing
D) To provide structural support to the lungs

Answer: C) To reduce friction during breathing
Explanation: The pleural cavity contains pleural fluid, which lubricates the surfaces of the lungs and thoracic cavity, reducing friction during respiration.

When swallowing, the uvula rises to close off the nasopharynx (the upper part of the throat behind the nose). This prevents food and liquid from entering the nasal cavity, directing it instead down the esophagus.

Where in the respiratory system does the transition from conducting to respiratory pathways occur?
A) Larynx
B) Bronchi
C) Bronchioles
D) Alveoli

Answer: C) Bronchioles
Explanation: The bronchioles are the smallest airways that lead to the alveoli, where gas exchange occurs, marking the transition from conducting to respiratory pathways.

Which part of the lungs is the site of the hilum?
A) Apex
B) Base
C) Medial surface
D) Diaphragmatic surface

Answer: C) Medial surface

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