FREE PHYSIOLOGY AND STUDY GAMES ABOUT PHYS

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FREE PHYSIOLOGY AND STUDY GAMES ABOUT PHYS

EXAM 2: CH 15

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -33 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: Since veins are more compliant than arteries, what does this say for the relationship of volume change and pressure change?

Answer:

There is a greater volume change for a given pressure change

Question 2: Define vascular compliance

Answer:

Volume change in response to a given pressure,or (change in volume)/(change in pressure)

Question 3: What can increase atrial pressure (this central venous pressure)?

Answer:

(1) heart muscle weakness; (2) increased blood volume; (3) Increased muscle tone of large veins; (4) dilation of the arterioles (the upper limit is ~20-30mmHg Question 4: Peripheral reduction of the aortic pressure pulse - fill in the blanks: The __the resistance of the arterial vessels (length, small diameter), the more the pressure pulse is __.

Answer:

Greater, reduced

Question 5: Fill in the blanks: in the aorta, pressure __ during systole and __ during diastole

Answer:

Increases, declines Question 6: Arterial pressure pulses - fill in the blanks: The __ the stroke volume, the __ the pressure pulse in the aorta

Answer:

Greater, Greater

Question 7: How do you (simply) calculate compliance?

Answer:

Compliance = Distensibility x Volume --> OR change in volume/change in pressure Question 8: What is the volume of the venous reservoirs in (each) of the large abdominal veins, liver sinuses, and venous plexus under the skin?

Answer:

~200-300 mL Question 9: What is the volume of the venous reservoirs in (each) of the lungs, heart, and spleen?

Answer:

~50-200 mL

Question 10: What can decrease atrial pressure (this central venous pressure)?

Answer:

(1) Exceptionally vigorous heartbeat; (2) Severe hemorrhage (lower limit is ~ -5mmHg

Question 11: Define the incisura on the aortic pressure pulse graph

Answer:

The notch; the back pressure when the aortic valves close

Question 12: What can increase R atrial pressure?

Answer:

usually heart failure or too large a transfusion

Question 13: What happens with aortic regurgitation?

Answer:

Occurs when the aortic valve fails to close, allowing aortic pressure to drop below normal, and the next stroke volume to be larger than normal (lung BP increases) - no notch/incisura in the aortic pressure pulse graph

Question 14: What can increase abdominal pressure?

Answer:

(1) Pregnancy; (2) Excessive fluid (kidney failure or liver cirrhosis); (3) A very large tumor

Question 15: What is arteriosclerosis?

Answer:

The aortic wall is stiff and resistant to stretching (i.e. vessel is no longer compliant, so pressure increases in the aorta)

Question 16: How do you calculate vascular distensibility?

Answer:

Distensibility = (increase in volume)/(inc pressure x original volume) Question 17: What will force the blood toward the heart, especially from the lower body?

Answer:

Contraction of the muscles surrounding a valve, compressing the valve

Question 18: How does anatomical compression increase venous resistance?

Answer:

(a)veins from the arms crossing the first rib; (b) veins from the lower body compressed by abdominal organs; (c)veins in the neck compressed by atmospheric pressure

Question 19: Describe arterial pressure pulses

Answer:

(1) Allow continuous pressure to the capillaries despite a pulsatile heart output

Question 20: What is aortic stenosis?

Answer:

Narrowing of the aortic valve opening, so less blood enters - aortic pressure pulse graph almost completely loses its notch/incisura

Question 21: Define vascular distensibility

Answer:

The amount of potential stretch of a vessel Question 22: Which is more distensible: arteries or veins? How much more are these distensible?

Answer:

Systemic veins are ~8 times are more distensible than systemic arteries

Question 23: What are the effects of gravity on venous pressure?

Answer:

(1) blood in the feet when standing has ~90mmHg to overcome to return to the heart; (2) veins in the neck collapse; (3) venous pressures in the dural sinuses are negative (the skull cannot collapse)

Question 24: What are varicose veins?

Answer:

Excess venous pressure (from standing long-term or pregnancy) stretches the veins so that the valves no longer hold, so more blood pools in the legs

Question 25: What does sympathetic stimulation do after severe hemorrhage?

Answer:

Maintain arterial pressure --> you can bleed a lot and still maintain blood pressure

Question 26: What are the 3 fxns of vascular distensibility?

Answer:

(1) Allows for vasodilation (decreases resistance, increases local blood flow); (2) Accommodates pulsatile output of the heart; (3) Provides a venous reservoir fxn

Question 27: What determines central venous pressure?

Answer:

Right atrial pressure Question 28: What happens to the pressure pulse peripherally, and what is this called?

Answer:

As the pressure pulse extends peripherally, the combined resistance and compliance reduce the pulse --> progressive damping of the pressure pulse