Ch1 Overview of the circulation

Question 1

What is the duration of systole during the cardiac cycle?
A.) 2/3 of the cardiac cycle
B.) 1/3 of the cardiac cycle 
C.) 1/2 of the cardiac cycle 
D.) 3/4 of the cardiac cycle

Answer 1

B.) 1/3 of the cardiac cycle

Question 2

What is the duration of Diastole during the cardiac cycle?
A.) 2/3 of the cardiac cycle
B.) 1/3 of the cardiac cycle 
C.) 1/2 of the cardiac cycle 
D.) 3/4 of the cardiac cycle

Answer 2

A.) 2/3 of the cardiac cycle

Question 3

What is the partial pressure of oxygen (Po2) in the pulmonary capillary bed?
A.) 100 mmHg 
B.) 40 mmHg
C.) 46 mmHg
D.) 75 mmHg

Answer 3

A.) 100 mmHg

Question 4

What is the partial pressure of carbon dioxide (Co2) in the pulmonary capillary bed?
A.) 100 mmHg 
B.) 40 mmHg
C.) 46 mmHg
D.) 75 mmHg

Answer 4

B.) 40 mmHg

Question 5

Partial pressures of the gases dissolved in the pulmonary capillary bed at the end of expiration must be equal to atmospheric pressures (760 mmHg). What are they?

Answer 5

Po2 = 100mmHg
Pco2 = 40 mmHg
Water vapor PH2O = 47 mmHg
Nitrogen PN2 = 573 mmHg

Question 6

Oxygenated blood carries roughly how much oxygen at a Po2 of 100 mmHg?
A.) 100 mL/O2/L
B.) 400 mL/O2/L
C.) 300 mL/O2/L
D.) 200 mL O2/L

Answer 6

D.) 200 mL O2/L

Question 7

Once blood makes its way into the tissue beds, how much oxygen does it unload
?
A.) 10%
B.) 25%
C.) 35%
D.) 45%

Answer 7

B.) 25%

and then takes up an additional burden of carbon dioxide.

Question 8

What is the average Po2 of blood in the venules leaving the tissues?
A.) 20 mmHg 
B.) 30 mmHg 
C.) 40 mmHg 
D.) 50 mmHg

Answer 8

C.) 40 mmHg

Question 9

What is the average PCo2 of blood in the venules leaving the tissues?
A.) 20 mmHg 
B.) 30 mmHg 
C.) 40 mmHg 
D.) 46 mmHg

Answer 9

D.) 46 mmHg

Question 10

The aorta and large arteries are;

Answer 10

low volume and high pressure

Question 11

The venules and veins are;

Answer 11

high volume and low pressure

Question 12

Efferent (motor) nerves in the SNS controls what ?

Answer 12

arteriolar resistances outside of the brain, heart, and lungs.

Question 13

Arterial pressure is continually monitored by what?

Answer 13

Arterial Baroreceptors located in;

Carotid sinuses at the bifurcations of the common carotids and in the arch of the aorta

Question 14

What happens when the arterial baroreceptors detect an increase in arterial pressure?

Answer 14

Produces an increase in in impulses in the Afferent (sensory) nerves serving these structures.

Question 15

High pressure detection in the carotid sinus sends signal through where?

Answer 15

Glossopharyngeal nerves to the brain (9th cranial nerve)

Question 16

High pressure detection in the aortic arch generates what ?

Answer 16

Increase in Afferent traffic in sensory fibers contained within the vagus nerve. (10th Cranial Nerve).

Question 17

Increase in B/P =

Answer 17

Medullary center send less Efferent impulses via the sympathetics to the arterioles and the structures relax a bit, bringing the pressure down.

Question 18

Decrease in B/P =

Answer 18

Baroreceptors send fewer impulses to the medullary CV centers, resulting in more sympathetic efferent impulses which leads to more arteriolar constriction.

Question 19

Q =

Answer 19

Quantity per time

Question 20

Kidneys receive what % of cardiac output?
A.) 100% 
B.) 75%
C.) 50%
D.) 25%

Answer 20

D.) 20 - 25% of flow at rest

1 L/m during exercise

Question 21

Lungs receive what % of cardiac output?
A.) 100% 
B.) 75%
C.) 50%
D.) 25%

Answer 21

A.) 100% ( The entire 5L/minute) of C.O.

Question 22

What is the average cross-sectional area of the average human aorta?
A.) 4.5 cm2
B.) 5.5 cm2
C.) 6.5 cm2
D.) 7.5 cm2

Answer 22

A.) 4.5 cm2

Question 23

The fastest linear blood velocities are found in the Aorta because 5,000 cm3/min must pass through a narrow orifice of 4.5 cm2 area. What does this calculate into?

Answer 23

5,000/4.5 = 1,111 cm/min or 185 mm/sec

Question 24

What is the linear blood velocity at the arteriolar level?
A.) 185 mm/sec
B.) 0.19 mm/sec
C.) 2.1 mm/sec
D.) 46 mm/sec

Answer 24

C.) 2.1 mm/sec

Question 25

What is the linear blood velocity at the tissue capillary level?
A.) 185 mm/sec
B.) 0.19 mm/sec
C.) 2.1 mm/sec
D.) 46 mm/sec

Answer 25

B.) 0.19 mm/sec

This is similar to the capillary beds of the lungs.

Question 26

What is the linear blood velocity at the Vena Caval level?
A.) 185 mm/sec
B.) 0.19 mm/sec
C.) 2.1 mm/sec
D.) 46 mm/sec

Answer 26

D.) 46 mm/sec

Question 27

Where does the largest pressure gradient occur within the circulation ?

Answer 27

Across systemic arterioles

where a drop of 60 mmHg is common.

Question 28

What is the mean pressure of the distal end of the arterioles which perfuses the capillary bed?

Answer 28

35 mmHg

Question 29

The mean pressure of the distal end of the arterioles which perfuses the capillary bed is 35 mmHg.

What is the final pressure as blood enters the venules?

Answer 29

7 mmHg

Question 30

What are the typical pressures in the RV?

Answer 30

22/0 mmHg

Question 31

What are the typical pressures in the PA?

Answer 31

22/8 mmHg

15

Question 32

What is the pressure gradient perfusing the lung?
A.) 4 mmHg 
B.) 15 mmHg 
C.) 11 mmHg 
D.) 25 mmHg

Answer 32

C.) 11 mmHg

Question 33

What is the pressure gradient perfusing the systemic circulation?
A.) 4 mmHg 
B.) 15 mmHg 
C.) 11 mmHg 
D.) 95 mmHg

Answer 33

D.) 95 mmHg