26 Cardiovascular Adaptation

Question 1

What are the 4 types of circulatory shock?

Answer 1

1) hypovolemic
2) distributive (Low TPVR, sepsis, anaphylaxis)
3) cardiogenic (low CO, MI, valvular disfunction)
4) obstructive (cardiac tamponade, P. embolism)

Question 2

What is heart failure?

Answer 2

failure of the heart to pump enough blood to satisfy the needs of the body at normal filling pressures. It can be left or right sided.

Question 3

What are some common causes of heart failure?

Answer 3

MI
chronic hypertension
valvular heart disease
AV shunts

Question 4

what is circulatory shock?

Answer 4

a state of inadequate tissue perfusion and oxygenation that is not always associated with hypotension.

Question 5

Why is central blood volume important?

Answer 5

central blood volume correlates with measurements of right atrial pressures and cardiac preload.

Question 6

What does hemorrhage do the the cardiac function curve?

Answer 6

It makes you slide downward on the same slope. Recall that decreasing preload does the same thing, so these are the same.

Question 7

What are some factors that restore BP and CO?

Answer 7

increasing TPVR
increasing HR
increasing contractility
increasing central blood volume

Question 8

what is the function of cardiopulmonary vagal afferents?

Answer 8

To sense decreases in cardiac filling pressures

Question 9

what is the function of arterial baroreceptors?

Answer 9

to sense decreases in arterial BP

Question 10

If there is a decrease in afferents from the baroreceptors and cardiopulmonary vagal receptors, what happens?

Answer 10

There is an increase in SNA, and decrease in paraSNA.

There is also a release of vasopressin, epi, & norepi.

Question 11

What is the Bezold Jarisch reflex?

Answer 11

overcompensation of the body that results in inhibition of SNA, activation of paraSNA, and worsening of hypotension. (Usually occurs with hemorrhage)

Question 12

what releases renin and why?

Answer 12

1) juxtaglomerular cells in the kidney in response to low blood flow
2) SNA

Question 13

What does renin do?

Answer 13

increases the formation of angiotensin I from angiotensinogen. Ace then converts angiotensin I to angiotensin II with release of aldosterone.

Question 14

what does contractility do to the cardiac function curve?

Answer 14

it shifts it up and to the left leading to increased SV and CO without increasing preload.

Question 15

T/F An increase in contractility results in decreased preload?

Answer 15

true because more is being pumped out.

Question 16

what is the effect of increasing SNA to the veins?

Answer 16

decreased venous compliance and increased central blood volume.

Question 17

what does decreasing venous compliance do to the cardiac function curve?

Answer 17

Nothing, but it shifts the vascular function curve because it increases the preload. Said another way, it slides up the cardiac function curve.

Question 18

T/F Increasing TPVR improves cardiac function?

Answer 18

False. Although it does not improve cardiac function (CO), it does maintain arterial BP which is essential for perfusion.

Question 19

What is systolic heart failure?

Answer 19

heart failure with reduced left ventricular ejection fraction.

Question 20

What is diastolic heart failure?

Answer 20

heart failure with a normal ejection fraction.

Question 21

what does contractility do to the cardiac function curve?

Answer 21

left shift with increased contractility

right shift with decreased contractility

Question 22

Where do you find Beta1 receptors? what activates them and what do they do?

Answer 22

Found on the heart

activated by SNA, and increases contractility

Question 23

what is the effect of SNA on alpha-adrenergic receptors on the arterioles?

Answer 23

vascoconstriction

Question 24

what are some potential side effects associated with SNA on the venous system?

Answer 24

Decreased compliance will help to return blood to the heart, but this can cause problems such as:

ascites
lower extremity edema
liver congestion

Question 25

what affect will a diuretic have on the heart?

Answer 25

decreases preload, but also decreases afterload.

Question 26

How do you treat a hemorrhage?

Answer 26

1) stop source of bleeding
2) restore blood volume
3) increase arterial BP
4) Bring everything into balance again (CO, Acid base balance, temperature, etc.)

Question 27

T/F To much SNA, norepi, Ang II, and aldosterone becomes maladaptive?

Answer 27

True.

Question 28

How do you treat heart failure?

Answer 28

Vasodilator therapy
Diuretics
Angiotensin II and aldosterone antagonists