Exam 3

Question 1

eccentric hypertrophy:

Answer 1

volume loading

Question 2

concentric hypertrophy

Answer 2

pressure loading

Question 3

triggers for vasodilation in the heart:

Answer 3

• vasodilators released from cardiac cells with low O2

- NO released from coronary vessels from shear stress

Question 4

how much O2 is extracted from arterial blood at normal resting HR?

Answer 4

70%

Question 5

potent vasodilators:

Answer 5

• adenosine
• CO2
• NO
• H+
• K+
• prostaglandins

Question 6

epicardial vessels have more _____ receptors:

Answer 6

alpha

Question 7

intramuscular arteries have more ____ receptors

Answer 7

Beta

Question 8

parasympathetic effect on coronary blood flow:

Answer 8

neurotransmitter: ACh
action: vasodilates coronary arteries
indirect effect:
-decrease HR, metabolic demand
-vasoconstriction

Question 9

sympathetic effect on coronary blood flow:

Answer 9

neurotransmitter: NE
action: vasocontriction (alpha receptors)
indirect effect:
-increase HR, myocardial contractility, metabolic demand
-vasodilation

Question 10

effect of epinephrine on coronary blood flow:

Answer 10

vasodilation (beta receptors)

-actions same as NE

Question 11

a-VO2

Answer 11

• indicates oxygen uptake into the tissue

- bigger the difference the more oxygen that was extracted from the blood

Question 12

HR max:

Answer 12

• responsiveness of heart to adrenergic stimulation
• no difference between the sexes
• no change with training

Question 13

why does SV plateau between 50%-70% of VO2 max?

Answer 13

-decreased filling time

Question 14

SVmax increases with training because:

Answer 14

• blood volume increases with aerobic training from kidney regulation
• more blood creates greater EDV
• increased EDV then greater contraction of heart

Question 15

difference in gender for stroke volume?

Answer 15

SV in men greater than SV in women

Question 16

increased sympathetic stimulation of alpha-receptors cause:

Answer 16

vasoconstriction

Question 17

venous content for a-vO2 diff determined by:

Answer 17

• capillarity
• # open capillaries
• myoglobin
• mitochondrial density
• mitochondrial enzymes

Question 18

byproducts that would cause vasodilation are:

Answer 18

adenosine
CO2
low O2 level

Question 19

relationship between BP and local blood flow/cardiac output?

Answer 19

the need to maintain BP determines the local blood flow and cardiac output

Question 20

ohm’s law:

Answer 20

difference in pressure over resistance in the vessel

Question 21

resistance of entire circulatory system is called:

Answer 21

total peripheral resistance

Question 22

short term regulation of mean arterial pressure is primarily:

Answer 22

under neural control

Question 23

the integration center of short term BP control:

Answer 23

medulla

Question 24

effectors of short term BP control

Answer 24

organs

blood vessels

Question 25

controllers of short term BP control:

Answer 25

- the autonomic nervous system - mostly sympathetic - is what connects integration center to organs

Question 26

location of cardiopulmonary baroreceptors:

Answer 26

- large veins - pulmonary vessels - atria - ventricles

Question 27

function of cardiopulmonary baroreceptors:

Answer 27

- sense a decrease in pressure secondary to decrease in blood volume - on beat by beat basis

Question 28

arterial baroreceptors have what type of feedback?

Answer 28

negative feedback loop

Question 29

cardiopulmonary baroreceptors have what type of feedback?

Answer 29

feedforward

Question 30

glomerular filtration rate is dependent on:

Answer 30

renal blood flow

Question 31

pressure diuresis

Answer 31

-increased body fluid, increases arterial pressure, increases water excretion

Question 32

pressure natriuresis

Answer 32

increased arterial pressure increases sodium excretion

Question 33

stimuli for ADH secretion:

Answer 33

- increased osmolarity - decreased blood volume - decreased blood pressure - nasea - hypoxia

Question 34

renin response to fall in pressure

Answer 34

-renin released from JG cells into afferent arteriole

Question 35

epinephrine increases CO by:

Answer 35

- increasing HR (B1) | - increasing SV (B1)

Question 36

epinephrine's effect on TPR:

Answer 36

- alpha adrenergic: vasoconstriction | - B2 adrenergic: vasodilation

Question 37

SNS activity is increased by a ____ in arterial baroreceptor firing frequency

Answer 37

decrease

Question 38

rate pressure product=

Answer 38

HR x SBP | -reflects myocardial work and myocardial demand for O2

Question 39

Fick's equation:

Answer 39

rate of diffusion of O2 and CO2 is dependent on: - pressure gradient - wall thickness

Question 40

what largely determines the oxygen carrying capacity of blood?

Answer 40

hemoglobin

Question 41

what favors oxygen unloading in muscle:

Answer 41

increased H+ (acidity) and temperature of a muscle

Question 42

factors effecting oxygen uptake and delivery:

Answer 42

1. oxygen content of blood 2. amount of blood flow to the muscles (capilary density) 3. local conditions within th emuscle (mitochondria density, myoglobin, pH, temp, etc)

Question 43

MVO2

Answer 43

-myocardial oxygen demand

Question 44

MVO2 effected by:

Answer 44

- HR | - SBP (resistance the heart is pumping against)

Question 45

afterload:

Answer 45

- determined by what arteries are vasodilated and vasoconstricted - the pressure in the aorta - viscosity plays minimal role compared to diameter of vessel

Question 46

preload:

Answer 46

pressure that blood exerts on heart in diastole