Exam 3: Lecture 13

Question 0

T/F: For cardiac failure, the heart must completely stop.

Answer 0

False, the heart must be unable to keep up with demands, not necessarily stop

Question 1

Define cardiac failure

Answer 1

Failure of the heart to pump enough blood to satisfy the needs of the body

Question 2

What are the 3 compensatory mechanisms by the ANS for acute cardiac failure?

Answer 2

1) Baroreceptor reflex
2) Chemoreceptor reflex
3) CNS ischemic response

Question 3

If all ventricular musculature is diffusely damaged but is still functional, ___________________.

Answer 3

The SNS strengthens this damaged musculature

Question 4

If part of the musculature is nonfunctional and part is still normal, ___________________.

Answer 4

The normal muscle is strongly stimulated

Question 5

During chronic compensation of moderate heart attacks, the maximum pumping ability of the partly recovered heart is still depressed _____.

Answer 5

To less than 1/2 normal

Question 6

T/F: An increase in right atrial pressure can maintain the cardiac output at a near normal level despite continued weakness of the heart.

Answer 6

True

Question 7

What causes pulmonary edema?

Answer 7

Loss of function to left side of heart results in blood from lungs not being pumped into heart. Hydrostatic pressure of capillaries rises in lungs as blood volume increases and fluid is pushed out.

Question 8

What are the two major problems associated with left heart failure?

Answer 8

Pulmonary edema

Pulmonary vascular congestion

Question 9

Arteriovenous fistula leads to high output cardiac failure. What is Arteriovenous fistula?

Answer 9

Heart overloads because of excessive venous return

Venous return curve rotates upward

Question 10

Beriberi leads to high output cardiac failure. What is beriberi?

Answer 10

Weakening of heart due to thiamin deficiency
Decreases blood flow to kidneys-> fluid retention
Venous return curve shifts right

Question 11

What makes the “lub” sound of the heart beat?

Answer 11

AV valves closing at onset of ventricular systole

Question 12

What makes the “dub” sound of the heart beat?

Answer 12

Semilunar valves closing at end of systole

Question 13

What is an example of a left-right shunt and what does it cause?

Answer 13

Patent ductus arteriosus

Causes blood to flow backward into heat and not flow through circulation

Question 14

What is an example of right-left shunt and what does it cause?

Answer 14

Tetralogy of fallot

Causes blood to flow from right to left side of heart, bypassing lungs

Question 15

Define circulatory shock.

Answer 15

Inadequate blood flow through the body, to the extent that the body tissues are damaged

Question 16

What two factors can severely reduce cardiac output?

Answer 16

Decreased ability of heart to pump blood

Decreased venous return

Question 17

T/F: Circulatory shock that results from diminished cardiac pumping ability is called cardiogenic shock.

Answer 17

True

Question 18

What causes decreased venous return?

Answer 18

Diminished blood volume
Decreased vascular tone
Obstruction of blood flow

Question 19

What causes decreased ability of heat to pump blood?

Answer 19

MI
Toxic state
Valve dysfunction
Heart arrhythmias

Question 20

Return of cardiac output to normal after cardiac shock is due to powerful sympathetic reflexes which cause…

Answer 20

Decrease in arterial pressure after hemorrhage

Decrease in pressure in the pulmonary arteries and veins in thorax

Question 21

The sympathetic reflexes result in what 3 effects?

Answer 21

1) Arterioles constrict
2) Veins/venous reservoirs constrict
3) heart activity increases markedly

Question 22

T/F: Autoregulation maintains normal levels in cerebral and cardiac vessels as long as arterial pressure is above 100 mmHg.

Answer 22

False, as long as arterial pressure is above 70 mmHgq

Question 23

Explain the baroreceptor reflexes in shock recovery.

Answer 23

Powerful sympathetic stimulation

Question 24

Explain the CNS ischemic response in shock recovery.

Answer 24

Powerful sympathetic stimulation

Not activated until under 50 mmHg arterial pressure

Question 25

Explain the reverse stress-relaxation of circulatory system in shock recovery.

Answer 25

Blood vessels contract around diminished blood volume so blood volume that is available more adequately fills circulation

Question 26

Explain the increased secretion of renin by kidneys & formation of angiotensin II in shock recovery.

Answer 26

Decreases water output

Question 27

Explain the increased secretion by posterior pituitary of ADH in shock recovery.

Answer 27

Increases water retention

Question 28

Explain the increased secretion by adrenal medullae of epinephrine/norepinephrine in shock recovery.

Answer 28

Increases HR

Question 29

What are the 4 compensatory mechanisms from shock?

Answer 29

Absorption of large quantities of intestinal fluid
Absorption of fluid into blood capillaries
Conservation of water/salt
Increased thirst/appetite for salt

Question 30

What is non-progressive shock?

Answer 30

Sympathetic reflexes and other factors work enough to prevent further deterioration of circulation
*Negative feedback mechanism

Question 31

What is progressive shock?

Answer 31

When arterial pressure falls too low, myocardium become weak and can’t pump, decreasing cardiac output even more
*Positive feedback mechanism

Question 32

What is neurogenic shock?

Answer 32

When vascular capacity increases so much that normal amount of blood becomes incapable of filing circulatory system

• May occur without loss of blood volume
• Major cause is loss of vasomotor tone

Question 33

What are the 3 causes of neurogenic shock?

Answer 33

Deep general anesthesia
Spinal anesthesia
Brain damage

Question 34

How does deep general anesthesia cause neurogenic shock?

Answer 34

Causes vasomotor paralysis

Question 35

How does spinal anesthesia cause neurogenic shock?

Answer 35

Blocks sympathetic nervous outflow

Question 36

How does brain damage cause neurogenic shock?

Answer 36

Causes vasomotor paralysis