OVERVIEW OF CIRCULATION BERNE

Question 1

Pump of the heart that propels blood through the lungs for exchange of O2 and CO2

Answer 1

Pulmonary circulation

Question 2

Pump of the heart that propels blood to all other tissues of the body

Answer 2

Systemic circulation

Question 3

The unidirectional flow of the heart is achieved by appropriate arrangement of ________________

Answer 3

Flap Valves

Question 4

Although cardiac output is intermittent, continuous flow to body tissues (periphery) occurs by:

Answer 4

Distension of aorta
and
Elastic recoil of walls of large arteries

Question 5

The distribution of blood circulating to the different regions of the body is determined by:

Answer 5

Output of the LV
and
Contractile state of the resistance vessels (arterioles)

Question 6

Blood entering the right ventricle via the right atrium is pumped through the pulmonary arterial system at a mean pressure about ______ that in the systemic arteries

Answer 6

One seventh

Question 7

What layer predominates in arterioles, elastic or muscular?

Answer 7

Muscular

Question 8

Frictional resistance reaches a maximal level in which blood vessels?

Answer 8

Arterioles

Question 9

The “stopcocks” of the vascular system

Answer 9

Arterioles

Question 10

Pressure drop is greatest across which segment of the small arteries and arterioles?
A. Initial
B. Elastic
C. Terminal

Answer 10

C. Terminal

Question 11

Pulsatile arterial blood flow is caused by:

Answer 11

Intermittent ejection of blood from the heart

Question 11

Pulsatile arterial blood flow is damped at the level of which blood vessels?

Answer 11

Capillaries

Question 12

Pulsatile blood flow is dampened by the combination of which factors?

Answer 12

Distensibility (of large arteries)
and
Frictional resistance (in small arteries and arterioles)

Question 13

What is the reason for the slow velocity of blood flow in the capillaries?
A. No muscular layer
B. Small cross-sectional area of individual capillaries than arterioles
C. Very large total cross-sectional areas of capillary bed

Answer 13

C. Total cross-sectional area is inversely proportional for the blood flow

Question 14

Between the aorta and the capillaries, the total cross-sectional area increases about ____-fold

Answer 14

500

Question 15

The volume of blood in the systemic vascular system is greatest in which blood vessels?

Answer 15

Veins and venules (64%)

Question 16

How many percent of the volume of blood is found in the aorta, arteries and arterioles?

Answer 16

14%

Capillaries - 6%
Veins and venules - 64%

Question 17

Which of the following is true?
A. The blood volume in the pulmonary vascular bed is about equally divided among the arterial, capillary, and venous vessels.
B. The cross-sectional area of the venae cavae is lesser than that of the aorta.
C. The velocity of blood flow is faster in the venae cavae than in the aorta

Answer 17

A.
The cross-sectional area of the venae cavae is greater than that of the aorta; thus, the velocity of blood flow is slower in the venae cavae than in the aorta

Question 18

What effect does hyperthyroidism (Graves’ disease) have on arterioles and pulsatile flow?

Answer 18

Arteriolar vasodilation causing diminished dampening effect on pulsatile arterial pressure = pulsatile flow in capillaries (seen in fingernail beds)