Question 1

Which of the following best explains why arterioles are considered the primary site of peripheral resistance in the cardiovascular system?

Accepted Answer

They possess a thick layer of smooth muscle, allowing for significant regulation of vessel diameter.

Question 2

A patient experiences severe blood loss from a traumatic injury. Which of the following physiological responses would most likely occur to help maintain blood pressure?

Accepted Answer

Activation of baroreceptor reflexes leading to increased sympathetic stimulation and vasoconstriction.

Question 3

Given the equation $$F = \frac{\Delta P}{R}$$, if atherosclerosis increases resistance ($$R) in an $$artery, what happens to blood flow ($$F) $$assuming pressure difference ($$\Delta P) $$remains constant?

Accepted Answer

Blood flow decreases because resistance is higher.

Question 4

Which of the following best describes the effect of increased capillary hydrostatic pressure on net filtration pressure?

Accepted Answer

It increases net filtration pressure, promoting more fluid movement into the interstitial space.

Question 5

Which of the following is a key structural difference between lymphatic capillaries and blood capillaries?

Accepted Answer

Lymphatic capillaries are closed at one end and have overlapping endothelial cells that act as one-way valves.

Question 6

If lymphatic flow is obstructed, which of the following is most likely to occur?

Accepted Answer

Edema due to accumulation of interstitial fluid.

Question 7

Which of the following statements about the innate immune response is correct?

Accepted Answer

It includes physical barriers, phagocytes, and complement proteins, but lacks memory.

Question 8

Complement proteins assist in the removal of pathogenic bacteria by:

Accepted Answer

Forming membrane attack complexes that lyse bacterial cells.

Question 9

Which of the following best describes the role of interferons in viral infections?

Accepted Answer

They signal neighboring cells to produce antiviral proteins, limiting viral replication.

Question 10

A vaccine provides immunity by:

Accepted Answer

Stimulating the adaptive immune system to produce memory cells against a specific antigen.

Question 11

Which of the following is an example of passive immunity?

Accepted Answer

Transfer of antibodies from mother to infant through breast milk.

Question 12

Where does immunocompetence occur for B cells and T cells, respectively?

Accepted Answer

B cells in the bone marrow; T cells in the thymus.

Question 13

Which statement best describes the function of MHC molecules in antigen presentation?

Accepted Answer

MHC molecules display antigen fragments on cell surfaces for recognition by T cells.

Question 14

Which of the following best describes the pathway of an inhaled molecule from the nares to the alveoli?

Accepted Answer

Nares → pharynx → larynx → trachea → bronchi → bronchioles → alveoli

Question 15

Why is surfactant important in the respiratory system?

Accepted Answer

It decreases alveolar surface tension, making it easier for alveoli to expand during inspiration.

Question 16

During inspiration, which of the following changes occur in the thoracic cavity?

Accepted Answer

Thoracic volume increases and intrapulmonary pressure decreases.

Question 17

According to Fick’s Law, which variable would most effectively increase the rate of gas diffusion across the respiratory membrane?

Accepted Answer

Increasing the partial pressure gradient of the gas.

Question 18

Using Dalton’s Law, what is the partial pressure of oxygen ($$pO_2) in $$dry atmospheric air if the total atmospheric pressure is $$760\ 	ext{mmHg}$$ and oxygen makes up $$21\% of $$the air?

Accepted Answer

$$pO_2 = 760$$ 	imes 0.21 = 159.6\ 	ext{mmHg}$$

Question 19

Which factor is most likely to promote the dissociation of oxygen from hemoglobin in peripheral tissues?

Accepted Answer

High carbon dioxide concentration and low pH.

Question 20

A patient is hyperventilating. What effect does this have on blood pH and carbon dioxide levels?

Accepted Answer

Blood pH increases and carbon dioxide levels decrease.

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