Exam 3 Flashcards Preview

Applied Physiology > Exam 3 > Flashcards

Flashcards in Exam 3 Deck (46):
1

eccentric hypertrophy:

volume loading

2

concentric hypertrophy

pressure loading

3

triggers for vasodilation in the heart:

-vasodilators released from cardiac cells with low O2
-NO released from coronary vessels from shear stress

4

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

70%

5

potent vasodilators:

-adenosine
-CO2
-NO
-H+
-K+
-prostaglandins

6

epicardial vessels have more _____ receptors:

alpha

7

intramuscular arteries have more ____ receptors

Beta

8

parasympathetic effect on coronary blood flow:

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

9

sympathetic effect on coronary blood flow:

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

10

effect of epinephrine on coronary blood flow:

vasodilation (beta receptors)
-actions same as NE

11

a-VO2

-indicates oxygen uptake into the tissue
-bigger the difference the more oxygen that was extracted from the blood

12

HR max:

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

13

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

-decreased filling time

14

SVmax increases with training because:

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

15

difference in gender for stroke volume?

SV in men greater than SV in women

16

increased sympathetic stimulation of alpha-receptors cause:

vasoconstriction

17

venous content for a-vO2 diff determined by:

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

18

byproducts that would cause vasodilation are:

adenosine
CO2
low O2 level

19

relationship between BP and local blood flow/cardiac output?

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

20

ohm's law:

difference in pressure over resistance in the vessel

21

resistance of entire circulatory system is called:

total peripheral resistance

22

short term regulation of mean arterial pressure is primarily:

under neural control

23

the integration center of short term BP control:

medulla

24

effectors of short term BP control

organs
blood vessels

25

controllers of short term BP control:

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

26

location of cardiopulmonary baroreceptors:

-large veins
-pulmonary vessels
-atria
-ventricles

27

function of cardiopulmonary baroreceptors:

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

28

arterial baroreceptors have what type of feedback?

negative feedback loop

29

cardiopulmonary baroreceptors have what type of feedback?

feedforward

30

glomerular filtration rate is dependent on:

renal blood flow

31

pressure diuresis

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

32

pressure natriuresis

increased arterial pressure increases sodium excretion

33

stimuli for ADH secretion:

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

34

renin response to fall in pressure

-renin released from JG cells into afferent arteriole

35

epinephrine increases CO by:

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

36

epinephrine's effect on TPR:

-alpha adrenergic: vasoconstriction
-B2 adrenergic: vasodilation

37

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

decrease

38

rate pressure product=

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

39

Fick's equation:

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

40

what largely determines the oxygen carrying capacity of blood?

hemoglobin

41

what favors oxygen unloading in muscle:

increased H+ (acidity) and temperature of a muscle

42

factors effecting oxygen uptake and delivery:

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)

43

MVO2

-myocardial oxygen demand

44

MVO2 effected by:

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

45

afterload:

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

46

preload:

pressure that blood exerts on heart in diastole