Module 2A: Body Structures and Organ Systems Flashcards
Plasma membrane
Description: Selectively permeable membrane (allows only certain substances through) made of phospholipids and proteins surrounding the entire cell
Function:
- Separates the internal components of the cell from the surrounding environment
- Essential to the life of the cell
Cytoplasm
Description: Gel-like fluid filling the inside of the cell that is comprised primarily of water, with electrolytes, metabolic waste products, and nutrients dissolved within it
Function:
- Contains many suspended organelles, or cell structures
- Medium for chemical reactions
Nucleus
Description: Large, spherical body near the center of the cell containing genetic material in the form of DNA
Function:
- Control center of the cell
- Regulates cell activity
- Houses genetic material
Nuclear membrane
Description: Double-layered, porous membrane surrounding the nucleus
Function: Protects the nucleus, allowing in only specific materials
Nucleolus
Description: Dark, dense body within the nucleus without an enclosing membrane; most cells contain one to four
Function: Forms RNA and ribosomes
Mitochondria
Description: Elongated, rod-shaped bodies filled with fluid, containing DNA; Known as the “power plant” of the cell
Function: Convert nutrients into energy for use by the cell/body; create adenosine triphosphate (ATP)
Ribosomes
Description: Small granules of RNA found in the nucleolus or cytoplasm
Function: Protein synthesis for both internal and external use
Endoplasmic reticulum
Description:
- Complex connection of membranous fluid-filled, flat sacs and tubular channels
- Connects the cell membrane to the nucleus membrane, as well as some organelles
- Comprised of the rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER)
Function:
- Transports materials throughout the cell
- RER: Supports the synthesis and transport of proteins
- SER: Supports the synthesis of some lipid molecules, including steroids
Golgi apparatus
Description: Four to six flat membranous sacs, connected to the endoplasmic reticulum; typically found near the nucleus
Function:
- “Packaging and shipping plant” of the cell
- Packages and releases materials secreted by the cell for external use
- Forms lysosomes for sure within the cell
Lysosomes
Description: Sacs surrounded by membranes created by the Golgi apparatus
Function: Digest waste materials including damaged materials found in the cell, old cell components, and materials entering the cell
Cytoskeleton
Description: Comprised of protein microfilaments and microtubules
Function:
- Maintains the shape and structure of the cell
- Keeps organelles in place and moves them throughout the cell as needed
Centrioles
Description: Pair of rod-shaped bodies made of microtubules found near the nucleus
Function: Participate in cell reproduction through the distribution of DNA to new cells
Cilia
Description: Short, hair-like microtubules projecting from the cell membrane
Function: Aid in the movement of substances along the surface of the cell
Flagella
Description: Long, hair-like microtubules, projecting from the cell membrane
Function: Move the cell itself, through a whip-like motion
Planes of the Body
Sagittal plane: Divides the body into left and right sides. Midsagittal refers to an equal division of left and right sides, running along the midline of the body.
Transverse plane: Divides the body into upper and lower sections, not necessarily equally
Frontal plane: Also called coronal plane, divides the body into anterior and posterior sections
Body Cavities
Cranial cavity
Spinal cavity
Thoracic cavity
Abdominal cavity
Pelvic cavity
Cranial Cavity
Within the skull; houses the meninges (brain)
Spinal Cavity
Traveling down the midline of the back and formed by the vertebrae, this contains the spinal cord
Thoracic Cavity
Within the chest; houses the lungs, heart, and major vessels
Abdominal Cavity
Within the abdomen; houses several major organs such as the stomach, liver, gallbladder, and intestines
Pelvic Cavity
Inferior to the abdominal cavity; houses the bladder and reproductive organs
Abdominal Quadrants
Right Upper Quadrant (RUQ)
Left Upper Quadrant (LUQ)
Right Lower Quadrant (RLQ)
Left Lower Quadrant (LLQ)
Abdominal Regions
Right Hypochondriac Region
Epigastric Region
Left Hypochondriac Region
Right Lumbar Region
Umbilical Region
Left Lumbar Region
Right Iliac Region
Left Iliac Region
Homeostasis
State in which the body’s systems and biological processes maintain stability.
Integumentary System
The following make up the integumentary system:
Skin (Epidermis layer, Dermis layer, Subcutaneous layer)
Hair follicles
Sebaceous (oil) glands
Fingernails and toenails
Sudoriferous (sweat) glands
Largest organ of the body
skin
Integumentary system accessory organs
hair, nails, and glands
Skin
Responsible for protection, temperature regulation, sensation, excretion, and vitamin D production
Layers of skin
Epidermis layer: Outermost layer of epithelial tissue, covers the external surface of the body
Dermis layer: Thick layer beneath the epidermis that contains arteries, veins, nerves
Subcutaneous layer: Loose, connective tissue composed of adipose tissue and lipocytes
Hair follicles
Generate hair
Sebaceous (oil) glands
Produce sebum to keep skin and hair soft and prevent bacteria from growing on the skin
Fingernails and toenails
Protect the ends of fingers and toes
Sudoriferous (sweat) glands
Produce sweat to aid in cooling the body
Skin Functions
Protection: The skin is the body’s first defense against illness and injury. It also protects the body’s internal structures from dehydration and UV exposure.
Temperature regulation: The skin plays a significant role in the body’s ability to maintain and regulate its temperature. When a person is hot or cold, superficial blood vessels in the skin dilate or constrict to control the flow of blood to the surface of the skin, aiding in warming or cooling.
Excretion: Perspiring aids in cooling the body but also results in the loss of water and minerals.
Sensation: The skin is loaded with nerve receptors to detect sensations (heat, cold, pain).
Vitamin D production: The body needs vitamin D to absorb calcium, which is needed for bone strength. Vitamin D comes from sun exposure to the skin.
Skeletal System
The skeletal system includes the following:
Axial skeleton
Appendicular skeleton
Ligament
Tendons
Connective Tissue/Cartilage
Skeletal System Functions
- structure and posture
- protection of the soft internal organs from injury
- serves as an attachment point for muscles in the body (This symbiotic relationship between bones and muscles often results in the systems being referenced as one- the musculoskeletal system).
Long Bones
These bones have epiphysis, diaphysis, and medullary cavity containing yellow bone marrow. The ends of long bones are covered by articular cartilage to allow joint movement without causing friction.
Examples: femur, humerus, tibia, fibula, ulna, radius
Short Bones
These are found in the wrists and ankles. Short bones are typically small and round.
Examples: carpals, tarsals
Flat Bones
The majority of surface area of these bones are flat or slightly curved.
Examples: skull, ribs
Irregular Bones
These include bones with an unusual shape that is typically related to its function.
Examples: vertebrae, pelvis
Sesamoid Bones
These small, round bones are found in joints that are held in place by tendons.
Example: patella
Red Bone Marrow
Found within bones, marrow is responsible for producing new blood cells. This process is known as hematopoiesis. Bones also store calcium, which is essential for proper cell function.
Appendicular Skeleton Bones
Upper extremities
- Scapula
- Clavicle
- Humerus
- Radius
- Ulna
- Carpals
- Metacarpals
- Phalanges
Lower extremities
- Pelvic girdle
- Femur
- Patella
- Tibia
- Fibula
- Tarsals
- Metatarsals
- Phalanges
Axial Skeleton Bones
- Skull
- Cervical vertebrae
- Thoracic vertebrae
- Lumbar vertebrae
- Sacrum
- Coccyx
- Ribs
Muscular System
The muscular system is made up of the following:
- Skeletal muscle
- Smooth muscle
- Cardiac muscle
- Tendons
Skeletal Muscle
Responsible for body movement; also called voluntary muscle or striated muscle
Smooth Muscle
Found within the walls of hollow organs and blood vessels and in the iris of the eye; also called involuntary muscle
Cardiac Muscle
Found only in the heart; cross-fibered to allow the heart to contract from the top and bottom to pump blood
Tendons
Ends of skeletal muscles that attach the muscle to a bone
Muscle System Functions
- movement, both voluntary (like walking) and involuntary (like digestion)
- cardiac muscle is made of specialized fibers that allow it to function as a pump
- muscles and skeleton work together to provide posture, movement, and other essential body functions.
Lymphatic System
The lymphatic system includes the following:
- Lymph nodes
- Lymph nodules
- Thymus
- Spleen
- Interstitial fluid
Lymph Nodes
Small, glandular structures concentrated in the neck, axilla, and groin that produce and store lymphocytes. Lymph nodes are home to macrophages that filter lymph.
Lymph Nodules
Masses of lymphoid tissue comprised of macrophages and lymphocytes. Lymph nodules are not encapsulated like lymph nodes.
Thymus
Located posterior to the sternum. The thymus is large in children and atrophies (shrinks) after adolescence. It is responsible for the production and maturation of T-cells.
Spleen
Largest lymphoid organ, located in the upper-left quadrant of the abdomen. It is home to macrophages that filter the blood.
Interstitial fluid
Tissue fluid found between cells. Once collected and filtered, it is called lymph
Immune System
The immune system relies on the lymphatic system to prevent infections in the body.
When a pathogen is detected, the lymphatic system begins activating the body’s defenses. A major component of these defenses are B-cells and T-cells.
*Creating immunity, or the ability to resist pathogens, is an essential function of the immune system. People are born with some immunity and develop more over time.
The immune system includes the following:
- Antigen
- Antibody
- Immunoglobulins: Antibodies
- B-cells
- T-cells
- Monocytes
Antigen
Foreign substance within the body
Antibody
Protein the body creates in response to specific antigens
Immunoglobulins
Antibodies
B-cells
Type of lymphocyte that can recognize antigens and responds by turning into plasma cells; these plasma cells then create antibodies against specific antigens
T-cells
Type of lymphocyte that can recognize antigens and attaches to them to attack the invading cells directly
Monocytes
Engulf and destroy pathogens that have been coagulated with antibodies
Types of Primary Immunity
- Naturally acquired active immunity: This occurs when a person has an infectious disease and then develops antibodies against the pathogen that caused the disease. The antibodies have a memory that prevents future infections by the same pathogen.
- Artificially acquired active immunity: This type of immunity is the result of administering a vaccination. The antibodies are activated by the vaccine and develop memory to recognize the pathogen in the future.
- Naturally acquired passive immunity: This is a short-lasting immunity transferred through the placenta and breast milk.
- Artificially acquired passive immunity: Also a short-lasting immunity, this is created by giving an exposed person antibodies containing blood products, as in an immune globulin.
Cardiovascular System
The cardiovascular system is made up of the following:
- Heart
- Artery/Arteriole
- Vein/Venule
- Capillary
- Endocardium
- Myocardium
- Pericardium
Heart
Located within the central part of the chest (mediastinum) and functions as a pump to move blood throughout the body
Artery/Arteriole
Thick-walled vessels that carry blood away from the heart. They propel blood with each contraction of the heart and are associated with various pulse points on the body. Smaller branches are arterioles.
Vein/Venule
Vessels that carry blood toward the heart. They are thinner-walled than arteries and contain valves to prevent backflow. Smaller branches are venules.
Capillary
The smallest blood vessels, which connect arterioles to venules. They aid in the exchange of oxygen and nutrients between blood and body cells.
Layers of the Heart
Endocardium: Innermost layer of cells that lines the atria, ventricles, and heart valves (which is part of the electrical conduction system)
Myocardium: Muscular layer of the heart (thickest layer)
Pericardium: Outermost layer of the heart; a membrane that surrounds the heart and secretes pericardial fluid
Cardiovascular System Functions
The structures of the cardiovascular system work together to pump blood throughout the body. Blood carries essential oxygen and nutrients to cells and aids in eliminating cell waste. Blood travels to the heart to be pumped to the lungs for oxygen and then back to the heart to travel to the rest of the body.
Average Adult BPM
The average adult heart beats 60 to 80 times per minute while at rest.
Chambers of the Heart
TOP Chambers: right and left atria
BOTTOM Chambers: right and left ventricles
Right Atria Function
Receives deoxygenated blood from the superior and inferior vena cava.
Left Atria Function
Receives oxygenated blood from the pulmonary veins (the only veins in the body that carry oxygenated blood)
Right Ventricle Function
Receives blood from the right atrium and sends deoxygenated blood through the pulmonary valve to the pulmonary artery and then to the lungs, where gas exchange occurs
Left Ventricle Function
Receives blood from the left atrium and sends the oxygenated blood through the aortic valve to the aorta, which then branches off into smaller arteries that carry the blood to the body
What is the valve between right atrium and right ventricle?
tricuspid valve
What is the valve between left atrium and left ventricle?
bicuspid (mitral) valve
Valve Function
To prevent the backflow of blood into the atria when the ventricles contract
Blood Circulation Pathways
systemic and pulmonary circulation
Systemic circulation
consists of arteries, arterioles, capillaries, venules, and veins in the body as a whole.
Pulmonary circulation
consists of arteries, arterioles, capillaries, venules, and veins going to, within, and coming from the lungs.
Electrical Conduction System
The heart contains its own electrical conduction system to keep the cardiac muscle contracting and blood flowing. This electricity can be mapped and analyzed to detect heart issues using an electrocardiogram (EKG).
Sinoatrial (SA) Node
The electrical impulse is generated by the sinoatrial (SA) node, also called the pacemaker of the heart.
Cardiac Cycle
The electrical impulse is generated by the sinoatrial (SA) node.
From the SA node, the impulse travels to the atrioventricular node, also called the gatekeeper.
From there, the impulse travels to the bundle of His and through the bundle branches located in the ventricular septum.
Finally, the electrical impulse reaches the Purkinje fibers. These fibers cause the ventricles to contract and pump blood into the pulmonary artery and aorta.
This entire process is the cardiac cycle.
Urinary System
The urinary system consists of the following:
- Kidneys
- Ureters
- Urinary bladder
- Urethra
Kidneys
Located on either side of the vertebral column at the level of the top lumbar vertebrae, the kidneys are responsible for removing waste from the blood and producing urine.
Ureters
These long tubes are responsible for carrying urine from the kidneys to the urinary bladder.
Urinary Bladder
This small muscular sac located within the pelvic cavity is responsible for storing urine.
Urethra
This tube is responsible for carrying urine from the urinary bladder to the outside of the body and is longer in males due to pelvic shape and position of the prostate.
The urinary meatus is located at the end of the urethra where urine exits the body
Urinary System Function
Primarily responsible for filtering blood to remove waste products.
This waste is then prepared for elimination by combining with water to form urine. Urine is produced in the kidneys and then stored in the urinary bladder to await elimination.
Gastrointestinal System
The gastrointestinal system is also known as the gastrointestinal tract. It begins with the mouth, or oral cavity. The following are part of the gastrointestinal system.
- Mouth (oral cavity)
- Pharynx
- Esophagus
- Stomach
- Small intestine (Duodenum, Jejunum, Ileum)
- Large intestine (Cecum, Ascending colon, Transverse colon, Descending colon, Sigmoid colon)
- Rectum
- Anus
- Liver
- Gall bladder
- Pancreas
The primary organs of the digestive system collectively make up the alimentary canal (the passage in which food passes through the body from the mouth to anus.)
There are also accessory organs of the digestive system that aid in various digestive functions.
Mouth (oral cavity)
This is responsible for initiating digestion, both mechanical (chewing) and chemical (saliva).
Pharynx
This includes the throat (the passageway for food between the oral cavity) and the esophagus (also part of the respiratory system).
Esophagus
This muscular tube connects the mouth to the stomach. It uses wave-like contractions called peristalsis to propel food into the stomach.
Stomach
Located below the diaphragm in the left upper quadrant (LUQ) of the abdominal cavity, the stomach receives food from the esophagus and continues breakdown using gastric juices. It then propels food to the small intestine. The stomach lining contains folds called rugae, allowing expansion.
Small intestine
This organ takes up most of the space within the abdominal cavity and is primarily responsible for absorption of nutrients. It is divided into the following sections.
- Duodenum
- Jejunum
- Ileum
Large intestine
Also called the colon, the large intestine completes absorption and forms feces from solid waste products. It is divided into the following sections.
- Cecum, which connects to the ileum, where the appendix is located
- Ascending colon
- Transverse colon
- Descending colon
- Sigmoid colon
Rectum
This is the end of the colon that stores feces until defecation.
Anus
This is the end of the rectum, which opens to the outside of the body to allow for elimination of feces.
Liver
This large organ is located in the right upper quadrant (RUQ) of the abdomen. It produces bile needed to break down fats.
Gall bladder
Located inferior to the liver, the gall bladder stores bile and connects to the duodenum.
Pancreas
Posterior to the stomach and connected to duodenum, the pancreas produces enzymes that aid with digestion
Gastrointestinal System Function
Digestion
- Digestion plays a vital role in the body’s ability to maintain homeostasis.
- Water and nutrients are essential for proper function of body systems, as well as organ, tissue, and cellular function.
Respiratory System
The following are part of the respiratory system:
- Nose
- Pharynx
- Larynx
- Trachea
- Lungs
Nose
The nose is made of bones, cartilage, and skin. It contains small hairs called cilia to prevent large particles from entering.
Pharynx
During respiration, air enters through the nose and mouth into the pharynx. The pharynx is also part of the digestive system.
Larynx
Superior to the trachea, the larynx produces a person’s voice.
Trachea
Also called the windpipe, the trachea extends from the larynx and branches into bronchi. It is lined with cilia.
Lungs
These two cone-shaped organs are located in the chest. The lungs contain bronchi, alveoli, and many blood vessels. The right lung is larger and divided into three lobes. The left lung has two lobes. Both lungs are surrounded by a membrane called pleura.
Respiratory System Functions
moving air into and out of the lungs, called respiration or breathing
How do the respiratory and cardiovascular systems work together?
The respiratory and cardiovascular systems work together to help deliver oxygen to the body via the blood and eliminate carbon dioxide.
External Respiration
The exchange of oxygen and carbon dioxide within the lungs is external respiration
Internal Respiration
The exchange within the hemoglobin of a red blood cell is internal respiration.
Nervous System
The nervous system controls all other body systems and is divided into two main sections—the central nervous system (CNS) and peripheral nervous system (PNS).
The nervous system contains the following:
- Brain
- Spinal cord
- Peripheral nerves
- Neuron
- Dendrites
- Nucleus
- Cytoplasm
- Axon
Brain
The brain coordinates most body activities and is the control center for the body as well as thought, emotion, and judgment. It is divided into four lobes: frontal, parietal, occipital, and temporal.
Spinal cord
The spinal cord provides a pathway for nerve impulses travelling to and from the brain and extends from the base of the brain to the lumbar vertebrae through the vertebral column.
Peripheral nerves
The peripheral nerves include 12 pairs of cranial nerves and 31 pairs of spinal nerves branching off from the spinal cord. They carry nerve signals between the body and the brain.
Neuron
The neuron is the functional unit of the nervous system
*generates an electrical impulse when stimulated
Dendrites
The dendrites have multiple branching structures.
Nucleus
The nucleus directs cellular activities.
Cytoplasm
The cytoplasm produces neurotransmitters and energy for the neuron.
Axon
The axon stores neurotransmitters.
Central Nervous System (CNS)
Comprised of the brain and spinal cord
Peripheral nNervous System (PNS)
Comprised of the peripheral nerves found throughout the body
The PNS is broken down further into two separate branches—the somatic nervous system and autonomic nervous system.
Afferent Nerve Cells
(aka called neurons) carry information about the body’s environment to the CNS
Efferent neurons
carry responses from the CNS to the body to initiate action
Somatic Nervous System
Branch of the PNS that controls the body’s voluntary (skeletal) muscles
Autonomic Nervous System
Branch of the PNS that controls the body’s automatic functions like breathing and digestion
broken down into 2 branches: The sympathetic branch controls the “fight or flight” response to stress. The parasympathetic branch returns the body to resting state after stress has been resolved and is responsible for maintaining homeostasis.
Sympathetic Branch
Branch of the autonomic nervous system that controls the “fight or flight” response to stress
Parasympathetic branch
Branch of the autonomic nervous system that returns the body to resting state after stress has been resolved and is responsible for maintaining homeostasis.
Endocrine System
The endocrine system is made of organs and glands that produce, store, and release hormones.
The endocrine system contains the following:
- hypothalamus
- pineal
- pituitary
- thymus
- adrenal
- pancreas
- thyroid
- parathyroid
- testes/ovaries
Two types of glands within the system:
1. exocrine
2. endocrine
Hormones
Chemicals used by the body to increase or decrease activity of the hormone’s specific target cells.
This aids the body in maintaining homeostasis.
Exocrine Glands
release hormones into a duct for delivery to the target cells
Endocrine Glands
release hormones directly into the blood stream.
Reproductive Systems Fucntion
The male and female reproductive systems work together to achieve fertilization and produce offspring.
Male Reproductive Organs
Female Reproductive Organs
Testes
Produce sperm and testosterone; located below the pelvic cavity on the outside of the body, within the scrotum
Scrotum
A pouch of skin that houses the testes
Penis
External cylinder-shaped organ that moves urine and semen out of the body
Epididymis
Coiled tube located superior to each testis; responsible for maturation of sperm cells
Vas deferens
Connects the epididymis to the urethra
Seminal vesicles
Sac-like organs that secrete seminal fluid that stimulate muscle contractions in the female reproductive organs to aid in propelling sperm forward
Prostate gland
Surrounds the proximal urethra; contracts during ejaculation to aid in forward movement of sperm; secretes fluid that protects sperm within the vagina
Bulbourethral glands (Cowper’s glands)
Inferior to the prostate gland; secrete fluid to lubricate the end of the penis to prepare for intercourse
Androgens
Group of male sex hormones
Testosterone
Most abundant and biologically active of male sex hormones
Ovaries
Pair of oval-shaped organs located within the pelvic cavity; produce ova, estrogen, and progesterone
Fallopian tubes
Muscular tubes with proximal opening near each ovary; connect distally to uterus; receive egg during ovulation
Uterus
Hollow muscular organ, lies low in pelvic cavity; receives fertilized egg, which implants into uterine wall for fetal development. If no egg has implanted into the uterine wall, the uterine lining sloughs off, causing menstruation. The lower portion of the uterus is the cervix, which creates a barrier between the uterus and vagina and dilates during childbirth.
Vagina
Muscular tube extending from the uterus to the outside of the body; expands during intercourse and childbirth
Labia majora
Folds of skin and adipose tissue that protect other external genitalia
Labia minora
Folds of skin within the labia majora, pinkish in color due to high blood circulation; form a hood over the clitoris
Clitoris
Highly sensitive erectile tissue located anterior to the urethra
Perineum
Area between the vagina and anus
Estrogen
Group of sex hormones
Progesterone
Hormone secreted by ovaries
Estradiol
Most abundant and biologically active female hormone
Female Reproductive Cycle
Refers to a monthly fluctuation of hormones that aids in reproduction and prepares the uterus for carrying a child. When fertilization does not occur, menstruation takes place, and the process begins again.
Primary systems responsible for maintaining homeostasis
nervous system and endocrine system
*all systems play a role
