General A&P Review

Question 1

Define homeostasis

Answer 1

Homeostasis is the self-regulating process by which biological systems maintain stability while adjusting to conditions optimal for survival. It refers to the state of steady internal physical and chemical conditions maintained by living systems. In simpler terms, it is the ability of an organism to maintain a stable internal environment.

Question 2

Define allostasis

Answer 2

The process by which the body responds to stressors in order to regain homeostasis.

Question 3

What is the role of the Hypothalamic-pituitary-adrenal axis (HPA)?

Answer 3

The main function of your HPA axis is to release cortisol (a glucocorticoid, or steroid hormone). This kicks off short-term bodily changes that allow you to respond to stress. The stress response is an automatic and instinctual process.

Question 4

Role of sympathetic nervous system in “fight or flight” response; release of catecholamines by adrenal medulla.

Answer 4

The “fight or flight” response of the sympathetic nervous system is a direct result of the multisystem action of catecholamines. Secretion from the adrenal medulla preceding the activation of the sympathetic nervous system functions to regulate blood pressure by contracting the smooth muscle in the vasculature (via alpha-1 receptors).

Question 5

What is the function of the sodium potassium pump?

Answer 5

Its fundamental purpose is to transport sodium and potassium ions across the cell in the ratio of 3: 2. It means, during one cycle, 3 sodium ions move out for every 2 potassium ions brought in. It contributes to the maintenance of a cells resting potential both during and after stimulation.

Question 6

What is the role of ATP in the sodium potassium pump?

Answer 6

The sodium-potassium pump carries out a form of active transport and pumps ions against their electrochemical gradients. ATP is the external energy source required for the process to occur. When ATP binds to the pump, ATP phosphorylates the pump and alters its shape, forming an opening towards the exterior of the cell.

Question 7

What is passive transport?

Answer 7

Does not require any energy and moves substances along their concentration gradient.

Question 8

What is active transport?

Answer 8

Requires energy and moves substances against the concentration gradient.

Question 9

What is secondary active transport?

Answer 9

A type of active transport that uses the energy generated by the movement of another molecule to transport different molecules molecules against its concentration gradient.

Question 10

What is the function of the plasma membrane?

Answer 10

The plasma membrane protects the cell from its surrounding environment and regulates which materials can pass in and out.

Question 11

What happens when the integrity of the plasma membrane is disrupted?

Answer 11

Disruption of the plasma membrane would affect the ability for the cell to maintain homeostasis and therefore its proper function.

Question 12

What is the function of mitochondria?

Answer 12

Mitochondria produce ATP through aerobic respiration.

Question 13

What is the unfolded protein response?

Answer 13

UPR is the cell’s way of maintaining balance of protein folding in the ER. UPR is activated in response to an accumulation of unfolded protein or misfolded proteins.
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Question 14

Sign vs Symptom

Answer 14

Signs are objective and externally observable, noticed by someone else.
Symptoms are subjective and describe how the person feels, experienced only by the person who has the condition.

Question 15

Cellular Hyperplasia

Answer 15

Hyperplasia is an increase in the tissue or organ size due to increased cell number, without an increase in cell size.

Question 16

Cellular Hypertrophy

Answer 16

Hypertrophy is an increase in the tissue or organ size due to an increase in cell size, without an increase in cell number. Hypertrophy usually occurs where there is increased functional demand on a tissue, or where there is hormonal stimulation.

Question 17

Cellular Atrophy

Answer 17

Atrophy is the shrinkage of a tissue or organ due to a decrease in size and/or number of cells. It can occur physiologically, for example when the uterus decreases in size after birth following the cessation of production of hormones which stimulated its growth, or pathologically, for example atrophy of an organ due to inadequate blood or nutritional supply.

Question 18

Cellular Metaplasia

Answer 18

Metaplasia is the reversible change of one differentiated cell type to another. It usually occurs in epithelial tissues as an adaptive response to cell stress; cells can be substituted by those types better suited to the environment.

Question 19

Cellular Dysplasia

Answer 19

Dysplasia refers to abnormal cell growth that is more serious that hyperplasia. It is a precancerous state.

Question 20

What are reactive oxygen species (ROS)?

Answer 20

Highly reactive chemicals formed from diatomic oxygen, water, and hydrogen peroxide. Could also be free radicals (unpaired electrons).

Question 21

What are antioxidants?

Answer 21

Molecules that neutralize free radicals by giving up some of their own electrons. They can be water or fat soluble.

Question 22

Describe the structure of capillaries.

Answer 22

Only 8-10 micrometers in diameter, made up of two layers of cells. Endothelial cells are inside the capillary and they control the flow of fluid nutrients and gases.
Epithelial cells from a protective layer around the endothelial cells.

Question 23

Blood Brain Barrier

Answer 23

The capillaries in the nervous system are able to maintain homeostasis by controlling the flow in and out of the capillaries through endothelial cells.

Question 24

Tight Junction in the gut

Answer 24

Tight junctions are formed by adjacent intestinal epithelia, they are essential to the function of the physical intestinal barrier and regulate the movement of various substances across the intestinal epithelium.

Question 25

Tight junctions in the blood brain barrier

Answer 25

In the BBB, tight junctions are the main functional components in sustaining the permeability barrier and controlling tissue homeostasis

Question 26

Transport proteins

Answer 26

Exist permanently within and span the membrane of a cell. Assist in the movement of substances by facilitated diffusion, active transport, and reverse diffusion. Ex: Hemoglobin which carries oxygen from the lungs to the body tissues

Question 27

Ligand-gated ion channels

Answer 27

Ion channels that can open in response to the binding of a ligand

Question 28

Teratogens

Answer 28

Substances that may cause birth defects in an embryo or fetus. The fetus is most vulnerable to their affects in the first 8 weeks of pregnancy.

Question 29

Allele

Answer 29

Refers to the different versions or variants of a specific gene. (Alternative form of a gene)

Question 30

Polar molecules

Answer 30

Are molecules where one end of the molecule is slightly positive while the other end is slightly negative. Ex: Water h20

Question 31

What is an ion

Answer 31

an atom or molecule that has a net electric charge due to the loss or gain of more one or more electrons.

Question 32

Lipophilic vs Lipophobic

Answer 32

Dissolves well in lipids or fats vs does not dissolve in lipids or fats

Question 33

Hydrophilic vs Hydrophobic

Answer 33

Attracted to water vs repelled by water