CV Physiology: Hemodynamics

Question 1

At a given flow in a large artery, if the lumen diameter is reduced by 50%, the velocity within that narrowed region will

A) increase 2-fold

B) increase 4-fold

C) increase 16-fold

D) not change

Answer 1

B) increase 4-fold

Question 2

Compared to laminar flow, what hemodynamic changes occur in a blood vessel when turbulent flow is present?

A) a greater perfusion pressure is required to drive a given flow

B) flow is increased at given perfusion pressure

C) resistance to flow decreases

D) the slope of the relationship between flow and perfusion pressure increases

Answer 2

A) a greater perfusion pressure is required to drive a given flow

Question 3

Resistance is determined by the ratio of perfusion pressure divided by blood flow.

True

False

Answer 3

True

Question 4

If a renal artery becomes diseased and its diameter is reduced by 75%, resistance along the length of that artery will be increased

A) 4-fold

B) 8-fold

C) 16-fold

D) 256-fold

Answer 4

D) 256-fold

Question 4

The pressure drop in the systemic circulation is greatest along which types of vessels?

A) aorta

B) large distributing arteries

C) arterioles

D) capillaries

Answer 4

C) arterioles

Question 5

If the perfusion pressure to an organ is held constant and the vascular resistance is decreased by infusion of a drug, the blood flow will decrease.

True

False

Answer 5

False

Question 6

When velocity of flow doubles across a narrowed region of a vessel

A) the kinetic energy is doubled within the narrowed region

B) the kinetic energy increases 16-fold within the narrowed region

C) the kinetic energy is reduced by 50% within the narrowed region

D) the potential energy (lateral pressure) is decreased within the narrowed region

Answer 6

D) the potential energy (lateral pressure) is decreased within the narrowed region

Question 7

Which of the following, by decreasing blood viscosity, can increase blood flow at a given perfusion pressure?

A) decreased temperature

B) decreased concentration of red blood cells

C) ow flow states

Answer 7

B) decreased concentration of red blood cells

Question 8

A single small artery branches into two smaller arteries, each having a resistance that is exactly twice that of the parent vessel

A) the pressure drop across the two daughter branches will be the same as the pressure drop across the parent artery

B) the pressure drop across the two daughter branches will be less than the pressure drop across the parent artery

C) the flow in each of the two daughter branches will be one-fourth the flow in the parent artery

D) the radius of each daughter branch must be one-half of the parent artery radius

Answer 8

A) the pressure drop across the two daughter branches will be the same as the pressure drop across the parent artery

Question 9

Compared to laminar flow, what hemodynamic changes occur in a blood vessel when turbulent flow is present?

A) a greater perfusion pressure is required to drive a given flow

B) flow is increased at given perfusion pressure

C) resistance to flow decreases

D) the slope of the relationship between flow and perfusion pressure increases

Answer 9

A) a greater perfusion pressure is required to drive a given flow