Chapter 1: An Introduction To The Human Body

Question 1

What are the six levels of structural organizations in the body and what do each of them do?

Answer 1

1) Chemical Level: Atoms (smallest units and participate in chemical reactions) and molecules (2+ atoms joined). Atoms include C, O, P, S, Ca, H, and N. Molecules include DNA and glucose.
2) Cellular Level: Molecules combined to form cells (smallest living units)
3) Tissue Level: Groups of cells working together to perform a function
4) Organ Level: Different types of tissues joined together
5) System Level: Related organs with a common function (ie digestive system)
6) Organism Level: All parts of the human body function together

Question 2

What are the 4 types of tissues and where are they found?

Answer 2

1) Epithelial: Covers body surface, lines organs and cavities, forms glands
2) Connective: Connects, supports and protects organs while distributing blood vessels to other tissues)
3) Muscular: Contracts to make body parts move and generates heat
4) Nervous: Carries info from one body part to another via nerve impulses

Question 3

What are the 6 important life processes?

Answer 3

1) Metabolism
2) Responsiveness
3) Movement
4) Growth
5) Differentiation
6) Reproduction

Question 4

What are the 2 phases of metabolism and what do they do?

Answer 4

1) Catabolism: Breaks down complex substances into simpler ones
2) Anabolism: Builds up complex substances from simpler ones

Question 5

Define interstitial fluid

Answer 5

Extracellular fluid (ECF) that fills narrow spaces between cells and tissues.

Question 6

Name some places (types of fluid) where ECF is found

Answer 6

Blood plasma (ECF within blood vessels), lymph, synovial fluid, cerebrospinal fluid, and aqueous humour & vitreous body

Question 7

How is interstitial fluid related to the blood capillaries?

Answer 7

Exchange across thin walls of blood capillaries which provides materials like glucose, oxygen and ions to tissue cells. This movement also removes waste like carbon dioxide from interstitial fluid.

Question 8

What are the 2 systems that implement the negative feedback system?

Answer 8

Nervous and Endocrine systems

Question 9

In a feedback system, what is a controlled condition?

Answer 9

A monitored variable (i.e., BP, body temp, glucose, etc)

Question 10

In a feedback system, what is a stimulus?

Answer 10

Any disruption that changes a controlled condition

Question 11

What are the 3 components of a feedback system?

Answer 11

1) Receptor: A body structure that monitors a controlled condition. Afferent pathway because info flows towards the control centre. Input is in the form of nerve impulses and chemical signals. Like nerve endings in the skin.
2) Control Centre: Usually the brain. Sets a range of acceptable values for the controlled condition, evaluates input, and generates output commands (nerve impulses or hormones/other chemical signals). Efferent pathway because flows away from control centre.
3) Effector: Any body structure that receives a response that changes the controlled condition. I.e., skeletal muscles can act as the effector when your body temperature drops because you shiver which then raises your body temp again.

Question 12

Describe the negative feedback loop

Answer 12

First a stimulus occurs (i.e., increased heat outside). This affects the controlled condition which is monitored by RECEPTORS. The RECEPTORS send nerve impulses or chemical signals to the CONTROL CENTRE which then provides nerve impulses or chemical signals (output) to EFFECTORS. The effectors bring about the response that alters the controlled condition. Homeostasis returns.

Question 13

What is positive feedback?

Answer 13

Strengthen or reinforce a change in one of the body’s controlled conditions

Question 14

Describe an example of a positive feedback loop

Answer 14

Childbirth: Contractions in wall of uterus force baby to cervix, which stretches the cervix (CONTROLLED CONDITION). The RECEPTORS are the stretch-sensitive nerve cells in the cervix which sends nerve impulses to the CONTROL CENTRE (brain). The brain interprets and releases oxytocin (output). The EFFECTORS are the muscles in the walls of the uterus and they contract more forcefully. The responses is that the baby’s body stretches the cervix more. Increased stretching of cervix causes release of more oxytocin which results in more stretching… cycle repeats. The birth is the interruption of the cycle… so then the cycle stops.

Question 15

Difference between disorder and disease

Answer 15

Disorder is any abnormality in structure or function, whereas a disease is more specific. It’s an illness that’s characterized by a set of symptoms and signs

Question 16

Difference between local and systemic disease

Answer 16

Local disease affects only one part of the body or a limited region (such as a sinus infection). A systemic disease affects either the entire body or several parts (ie influenza)

Question 17

Difference between signs and symptoms

Answer 17

Signs are objective and can be observed by clinicians. Symptoms are subjective and is not apparent to the observer.

Question 18

Difference between the prone and supine positions

Answer 18

Prone position is the body lying facedown and supine is the body lying face up

Question 19

Name the principle regions of the body

Answer 19

Head, neck, trunk, upper limbs, and lower limbs

Question 20

LOOK AT FLASHCARD IMAGES FOR DIAGRAMS

Answer 20

LOOK AT FLASHCARD IMAGES FOR DIAGRAMS

Question 21

Describe sagittal, midsagittal and parasagittal planes

Answer 21

Sagittal plane is vertical and divides the body into left and right. Midsagittal divides the body into EQUAL left and right parts. Parasagittal divides the body into UNEQUAL left and right parts. It does not cross the midline.

Question 22

Describe the Frontal Plane

Answer 22

The Frontal Plane divides the body/organ into anterior (front) and posterior (back)

Question 23

Describe the Transverse Plane

Answer 23

Divides the body organ into superior (head) and inferior (legs) parts

Question 24

What is an oblique plane?

Answer 24

Passes through the body at an angle other than 90 degrees. The other planes all pass through at 90 degrees

Question 25

What is a “section”?

Answer 25

Cut of a body/organ along a plane

Question 26

FOR DIFFERENT BODY CAVITIES LOOK AT FLASHCARD IMAGES

Answer 26

FOR DIFFERENT BODY CAVITIES LOOK AT FLASHCARD IMAGES

Question 27

Define Membrane

Answer 27

Membrane is a thin pliable tissue that covers, lines, patricians, or connects structures

Question 28

Define serous membrane and what are the layers?

Answer 28

Associated with body cavities. Does not open to outside. Has two layers. The visceral layer covers and adheres to viscera within cavities. The parietal layer is a thin epithelium that lines the walls of cavities

Question 29

What is serous fluid?

Answer 29

Serous fluid lets viscera to slide somewhat during movement. Like when lungs inflate and deflate when we breathe

Question 30

What is “pleura”?

Answer 30

Serous membrane of pleural cavities. Has viscera and parietal pleura

Question 31

Define “Pericardium”

Answer 31

Serous membrane of pericardial cavity. Visceral pericardium covers the surface of the heart and parietal lines the chest wall. The pericardial cavity is between them and is lined with small lubricating fluid.

Question 32

What is “Peritoneum”?

Answer 32

Serous membrane of abdominal cavity. Visceral peritoneum covers the abdominal cavity and parietal covers inferior surface of diaphragm. Peritoneal cavity contains small amounts of lubricating fluid.

Question 33

What is “Retroperitoneal”?

Answer 33

Organs that are posterior to the peritoneum. Includes kidneys, adrenal glands, pancreas, duodenum, ascending and descending colons, and parts of the abdominal aorta and inferior vena cava

Question 34

What is an X-Ray?

Answer 34

A single barrage of X-rays pass through the body and results in a 2D image. These x-rays don’t easily pass through dense structures so bones appear white. But hollow structures like the lungs appear black and intermediate density structures like the skin, fat and muscle appears grey.

Question 35

How do you make hollow structures visible on an x-ray? Name some examples

Answer 35

Use a contrast medium. Some examples are angiography (blood vessels), intravenous urography (urinary system), and barium contrast x-rays (GI system)

Question 36

What’s Magnetic Resonance Imaging (MRI)

Answer 36

A high energy magnetic field that causes protons (positively charged particles) in the body fluids and tissues to arrange themselves in relation to the field. A pulse of radio waves reads these ion patterns and produces a 2D or 3D image on the monitor. Soft tissues but not bones. Used to differentiate between normal and abnormal tissues. Detects tumours, artery-clogging plaques, blood flow, brain abnormalities, and musculoskeletal, liver and kidney disorders.

Question 37

Computer Tomography (CT)

Answer 37

X-ray beam traces an arc at multiple angles around the body. Transverse section of the body is shown on monitor. Soft tissues and organs. Differing tissue densities show up as grey. 3D. Usually targets the torso. Good for detecting lung cancers, coronary artery disease and kidney disease.

Question 38

Coronary (Cardiac) Computer Tomography Angiography (CCTA)

Answer 38

Iodine-containing contrast medium is injected into a vein and a beta-blocker is given to decrease heart rate. X-ray beams trace an arc around the heart and the scanner detects the x-ray beams and transmits them to a computer. 3D image of coronary blood vessels. Looks for coronary artery blockages

Question 39

Ultrasound Scanning

Answer 39

High frequency sound waves produced by handheld wand that reflect off body tissues. Image is called a sonogram. Observes the size, location and actions of organs and blood flow through blood vessels (Doppler ultrasound)

Question 40

Positron Emission Tomography (PET)

Answer 40

A substance that emits positrons is injected into the body. The positrons clash with electrons while in the body, giving off gamma-rays that are detected by gamma cameras and produces a video on a monitor. Used to look at the physiology of body structures, like metabolism of brain or heart.

Question 41

Endoscopy (and name some types)

Answer 41

Visual exam of inside the body’s organs or cavities using an instrument with a lense called an endoscope.

Examples: Colonoscopy, laparoscopy (looks @ abdominopelvic cavity) and arthroscopy (examines interior of a joint like the knee)

Question 42

Radionuclide Scanning

Answer 42

A radionuclide (radioactive substance) is introduced intravenously into the body and carries by the blood to tissues to be managed. Gamma rays emitted by the radionuclide are detected by gamma ray cameras and fed to computer. Areas of intense colour = most active. Single-photon-emission computer tomography (SPECT) scanning studies the brain, heart, lungs, and liver. Used to study the ACTIVITY of tissue or organ.