Heller Ch. 10

Question 1

What are the three ways of INCREASING stroke volume?

Answer 1

Increase preload
Increase contractility
Decrease afterload

Question 2

What is proportional to preload?

Answer 2

Central blood volume

Question 3

What are six ways of INCREASING central blood volume? (Thus increasing preload, thus increasing SV)

Answer 3

Increase total blood volume
Increase peripheral venous tone
Increase skeletal muscle pump
Increase respiratory pump
Decrease standing
Decrease cardiac output

Question 4

What increases contractility? (Thus increasing SV)

Answer 4

Increased sympathetic activity (NE–>beta receptors)

Question 5

What increases venous tone? (Thus increasing central blood volume, thus increasing preload, thus increasing SV)

Answer 5

Increased sympathetic activity (NE–>alpha receptors)

Question 6

What is proportional to afterload?

Answer 6

TPR (arterial tone)

Question 7

What are two ways to DECREASE TPR? (Thus decrease preload, thus increase SV)

Answer 7

Decrease sympathetic activity (NE–>alpha receptor)

Increase local metabolites (increase local metabolic rate)

Question 8

How does the “respiratory pump” (deep and rapid breathing) promote venous return? (Thus increase central blood volume, thus increase preload, thus increase SV)

Answer 8

Inspiration decreases thoracic pressure

Question 9

What is one possible concern with a respirator?

Answer 9

A respirator increases thoracic pressure…may have CV implications

Question 10

What happens when lung mechanoreceptors are stretched?

Answer 10

Vagal activity is INHIBITED–>increased HR

Question 11

What response do cardiopulmonary baroreceptors have after inspiration?

Answer 11

Increase parasympathetic activity in the heart

Question 12

What is the net effect of inspiration on blood pressure?

Answer 12

Blood pressure is increased (increased SV and HR)

Question 13

What is the arterial baroreceptor response to the increased blood pressure?

Answer 13

Inhibit sympathetic activity

Increase parasympathetic activity

Question 14

What is the valsalva maneuver? What are some examples?

Answer 14

Forced expiration against a closed glottis

Taking a big ol’ dukie
Heavy lifting

Question 15

What are the consequences of the valsalva maneuver?

Answer 15

Increased arterial pressure (particularly on aorta)–> Fall in venous return and BP–>
Compensatory reflex increase in HR and TPR

Question 16

What happens upon cessation of the valsalva maneuver?

Answer 16

Abrupt fall in BP (reduced intrathoracic pressure)
Increased peripheral return–> increased CVP–>
Increased SV, CO, MAP–>
Bradycardia

Question 17

What combo/series of blood pressures can lead to a stroke?

Answer 17

High venous pressure… Followed by

High arterial and pulse pressure

Question 18

What effect does standing have on venous transmural pressure in the lower extremities?

Answer 18

Transmural pressure is increased…decreases central venous return

Question 19

What happens as a result of increased transmural pressure in the lower extremities?

Answer 19

Distends the compliant peripheral veins

Increases venous volume

Question 20

What happens to transcapillary filtration rate upon standing?

Answer 20

Increased filtration rate…due to increased arterial pressure

Question 21

What causes weight loss and hypovolemia upon long-term bed rest?

Answer 21

The kidney

Question 22

What is the concern about standing after long-term bed rest?

Answer 22

Shifting an already low blood volume from central to periphery–>dizziness

Question 23

What effect does exercise have on skeletal muscle vascular resistance–>TPR?

Answer 23

Exercise decreases the resistance

Question 24

What is the effective of decreased TPR?

Answer 24

Decreased arterial pressure (MAP=COxTPR)

Question 25

What is the end result of exercise on pressure regulation?

Answer 25

Decreased parasympathetic activity | Increased sympathetic activity

Question 26

What causes the decreased parasympathetic/increased sympathetic activity during exercise?

Answer 26

Increased set point from the cerebral cortex and increased skeletal muscle chemo/mechano receptor activity Decreased arterial baroreceptor firing

Question 27

What are CV responses to dynamic exercise?

Answer 27

Skeletal muscle pump Respiratory pump Increased cardiac reserve

Question 28

What is a major difference between dynamic and static exercise?

Answer 28

Dynamic has a significantly larger fall in TPR

Question 29

What are the CV responses to static exercise?

Answer 29

Less of an increase in HR and CO | More increase in diastolic/systolic/mean pressures

Question 30

What is the biggest advantage (from a CV perspective) of exercise?

Answer 30

Increased blood volume

Question 31

Other than increased blood volume, what are some other CV benefits of exercising?

Answer 31

Decreased HR Increased SV Decreased resting MAP

Question 32

What is the effect of the placenta on TPR?

Answer 32

The placenta decreases TPR by 40%

Question 33

What is the percent increase in blood volume of pregos?

Answer 33

50%

Question 34

What adjustment do arterioles go through after birth?

Answer 34

From thick-walled and small-diameter to thin-walled and large-diameter

Question 35

What cardiac changes are age-dependent?

Answer 35

Decrease in resting and maximum cardiac index Decrease in maximum HR Increase in contraction and relaxation time Increase in myocardial stiffness during diastole Decrease in number of functioning myocytes Accumulation of pigment in the myocardial cells

Question 36

What vascular changes are age-dependent?

Answer 36

Decrease in capillary density in some tissues Decrease in arterial and venous compliance Increase in TPR

Question 37

What is the effect of age-related increase in TPR?

Answer 37

Increase in pulse pressure | Increase in MAP-->increased afterload--> decreased cardiac index

Question 38

What does estrogen directly do for the CV?

Answer 38

Lowers arterial BP Greater aortic compliance Improved ability to induce vasodilatory mechanisms

Question 39

What is the result of the changes estrogen has on the CV?

Answer 39

Lower cardiac afterload-->lower LV mass:body mass index

Question 40

What are other cardiac differences are there between men and women?

Answer 40

Women: Have lower HR Longer QT (greater risk of long-QT syndrome and Torsades) Twice as likely to have AV nodal re-entry tachycardias