Question 1

A patient is experiencing increased peripheral resistance due to vasoconstriction. According to Poiseuille's Law, which equation best describes the relationship between vessel radius ($r$) and resistance ($R$)?

Accepted Answer

$R \propto \frac{1}{r^4}$

Question 2

Which of the following best explains why capillaries are the primary site for exchange of gases and nutrients with tissues?

Accepted Answer

They have thin walls and a large total cross-sectional area.

Question 3

A patient with a blocked lymphatic vessel in the lower limb is likely to develop which of the following conditions, and why?

Accepted Answer

Edema, due to accumulation of interstitial fluid that cannot be drained.

Question 4

During exercise, blood flow to skeletal muscles increases. Which mechanism is primarily responsible for this change?

Accepted Answer

Local vasodilation in response to increased metabolic activity.

Question 5

If a person has a total blood volume of 5 liters, and 60% of it is found in the veins at any given time, how much blood is in the veins?

Accepted Answer

$5 	imes 0.6 = 3$ liters

Question 6

Which of the following best describes the function of valves in veins?

Accepted Answer

They prevent the backflow of blood, especially in the limbs.

Question 7

A patient is given a drug that causes widespread vasoconstriction. What immediate effect would you expect on systemic blood pressure?

Accepted Answer

Increase, due to increased peripheral resistance.

Question 8

Which of the following is NOT a function of the lymphatic system?

Accepted Answer

Transporting oxygen to tissues.

Question 9

A patient with a deficiency in T cells would have the most difficulty with which of the following?

Accepted Answer

Cell-mediated immunity against viruses and cancer cells.

Question 10

Which of the following best explains why pulse pressure decreases as blood moves from arteries to capillaries?

Accepted Answer

The increased total cross-sectional area of capillaries dissipates the pressure.

Question 11

Which hormone is released in response to increased blood volume and acts to decrease blood pressure by promoting sodium excretion?

Accepted Answer

Atrial natriuretic peptide (ANP)

Question 12

A patient is found to have a blockage in the right lymphatic duct. Which region of the body would most likely show signs of lymphedema?

Accepted Answer

Right arm and right side of the head and thorax

Question 13

Which of the following best describes the role of antigen-presenting cells (APCs) in the immune response?

Accepted Answer

They display foreign antigens on their surface using MHC proteins to activate T cells.

Question 14

A patient receives a vaccine containing inactivated virus. What type of immunity is being conferred?

Accepted Answer

Artificially acquired active immunity

Question 15

Which of the following is a mechanical barrier to pathogen invasion?

Accepted Answer

Intact skin

Question 16

A patient with severe liver disease has reduced plasma protein levels. What effect would this have on capillary exchange?

Accepted Answer

Decreased osmotic pressure, leading to increased fluid loss into the interstitial space (edema).

Question 17

Which of the following best explains why lymphatic capillaries are highly permeable to proteins and pathogens?

Accepted Answer

They have overlapping endothelial cells that function as one-way mini-valves.

Question 18

A patient is exposed to a novel pathogen and develops a fever and inflammation. Which type of immunity is primarily responsible for this initial response?

Accepted Answer

Innate (nonspecific) immunity

Question 19

Which of the following best describes the process of diapedesis?

Accepted Answer

The movement of leukocytes out of capillaries into tissues.

Question 20

A patient with a genetic defect in complement proteins would be most susceptible to which of the following?

Accepted Answer

Bacterial infections due to impaired opsonization and lysis.

Cardiovascular and Lymphatic System: Blood Vessels, Circulation, and Immunity

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