Chapter 23 - Guyton

Question 1

first heart sound

Answer 1

A-V valves closing at the beginning of systole

Question 2

second heart sound

Answer 2

semilunar valves closing at the end of systole

Question 3

What causes the heart sounds?

Answer 3

vibration of the taut valves immediately after closure, along with vibration of the adjacent walls of the heart and major vessels around the heart

Question 4

What causes the “third heart sound”?

Answer 4

middle third of diastole, blood rushing into the ventricles

Question 5

What causes the “fourth heart sound” (not heard by auscultation)?

Answer 5

atrial contraction

Question 6

By far the greatest number of valvular lesions results from _________ ______.

Answer 6

rheumatic fever (autoimmune disease in which the heart valves are likely to be damaged or destroyed)

Question 7

A valve in which the leaflets adhere to one another so extensively that blood cannot flow through it normally is said to be _________.

Answer 7

stenosed

Question 8

When the valve edges are so destroyed by scar tissue that they cannot close as the ventricles contract, __________ (backflow) of blood occurs when the valve should be closed.

Answer 8

regurgitation

Question 9

If you hear a heart sound several feet away from a patient, what might the patient have?

Answer 9

aortic stenosis

Question 10

What might a patient have if you hear a murmur during diastole?

Answer 10

aortic regurgitation; blood flows backward from the high-pressure aorta into the left ventricle, causing a “blowing” murmur of relatively high pitch with a swishing quality heard maximally over the left ventricle

Question 11

What might a patient have if you hear a murmur during systole?

Answer 11

mitral regurgitation; blood flows backward through the mitral valve into the left atrium during systole

Question 12

Why might you not hear a murmur in a patient with mitral stenosis?

Answer 12

During the early part of diastole, a left ventricle with a stenotic mitral valve has so little blood in it and its walls are so flabby that blood does not reverberate back and forth between the walls of the ventricle.

Question 13

Murmurs that occur during systole versus diastole.

Answer 13

systole - aortic stenosis and mitral regurgitation; diastole - aortic regurgitation and mitral stenosis

Question 14

What effect would aortic stenosis and aortic regurgitation have on stroke volume?

Answer 14

decreased

Question 15

What are two compensations in the body for aortic stenosis and aortic regurgitation?

Answer 15

hypertrophied left ventricle and increased blood volume

Question 16

The buildup of blood in the left atrium (from mitral valvular disease) causes progressive increase in left atrial pressure, and this eventually results in?

Answer 16

pulmonary edema

Question 17

In late stages of mitral stenosis, atrial fibrillation usually occurs. Why?

Answer 17

The high left atrial pressure in mitral valvular disease also causes progressive enlargement of the left atrium, which increases the distance that the cardiac electrical excitatory impulse must travel in the atrial wall (circus movements).

Question 18

Three major types of congenital anomalies of the heart and its associated vessels:

Answer 18

stenosis, left-to-right shunt (bypass systemic circulation), right-to-left shunt (bypass lungs)

Question 19

What is the ductus arteriosus?

Answer 19

the pulmonary arterial blood to flow through a special artery present in the fetus that connects the pulmonary artery with the aorta called the ductus arteriosus, thus bypassing the lungs (blood is oxygenated by the placenta)

Question 20

The major effects of patent ductus arteriosus on the patient are decreased _______ and _________ reserve

Answer 20

cardiac, respiratory (left ventricle is pumping about two or more times the normal cardiac output and body can never sustain increased activity)

Question 21

By age 1-3 years, a baby with patent ductus arteriorsus will exhibit which audible heart murmur?

Answer 21

machinery murmur

Question 22

Abnormalities of Tetralogy of Fallot.

Answer 22

aorta originates from right ventricle, pulmonary artery is stenosed, left ventricle flows into right ventricle, enlarged right ventricle (this baby will be blue)

Question 23

What is used during cardiac surgery to maintain circulation?

Answer 23

extracorporeal circulation (heart-lung machine)