LESSON 19 - control of blood flow during exercise

Question 1

how do cardiac output and muscle blood flow increase ? (proportional to what)

Answer 1

increase in proportion to metabolic rate

Question 2

when we increase our cardiac output as a function of exercise intensity what do we also match ?

Answer 2

match it very well with our muscle blood flow

Question 3

what is hyperemic ?

Answer 3

higher blood flow than normal

Question 4

what is the formula for Q = ?

Answer 4

Q = HR x SV

Question 5

how does HR rise ?

Answer 5

linearly

Question 6

how does SV increase ?

Answer 6

increases initially and then plateaus as HR increases

Question 7

an increase in HR, CO, SV and VO2 means an increase or decrease in ATP ?

Answer 7

increase in ATP

Question 8

what is the SA node innervated by ?

Answer 8

the autonomic nervous system

Question 9

what controls heart rate ?

Answer 9

SA node

Question 10

what does the SA node inhibit ?

Answer 10

the parasympathetic nervous system

Question 11

what is vagus ?

Answer 11

slows down HR and runs parallel to carotid arteries to the heart

Question 12

what is responsible for slowing down heart rate ?

Answer 12

vagus

Question 13

what is the vagus anatomically …

Answer 13

a nerve (cranial nerve 10)

Question 14

what is the increase in contractility during exercise ?

Answer 14

inotropy

Question 15

what is inotropy ?

Answer 15

is the strengthening/weakening function of the cardiac tissue

Question 16

why is inotropy a good thing ?

Answer 16

helps you push more blood

Question 17

what is term used to define (increasing contractibility) ?

Answer 17

inotropy

Question 18

define “inotrope” :

Answer 18

agent that alters the force of muscle contraction

Question 19

what are the two examples of positive inotropes ?

Answer 19

norepinephrine and epinephrine

Question 20

what does an increase positive inotrope concentration mean for cardiac muscle tension for a given preload and rate of muscle tension development ?

Answer 20

increase cardiac muscle tension for a given preload and increased rate of muscle tension development

Question 21

if there is an increase cardiac muscle tension is it better or worse able to go againts resistance ?

Answer 21

better able

Question 22

what does an increase in inotropy mean for SV ?

Answer 22

increase in SV

Question 23

during exercise what happens to inotropy ?

Answer 23

increase in inotropy

Question 24

during exercise when we have an increase in inotropy what do we see ?

Answer 24

• increase firing of sympathetic nerves innervating ventricle
• increase circulating catecholamines
• intensity-dependent

Question 25

what are the two catecholamines ?

Answer 25

epinephrine and norepinephrine

Question 26

where do catecholamines come from ?

Answer 26

adrenal glands

Question 27

what happens to sympathetic input to the heart with higher exercise intensity ?

Answer 27

the higher the exercise intensity, the more sympathetic input to the heart, the more the higher the contraction fo circulating catecholamines and the greater the contractibility will be

Question 28

does muscle contraction help with increased or decreased venous return ?

Answer 28

increased

Question 29

why does muscle contraction help with venous return ?

Answer 29

propels blood away from muscle and back to the heart

Question 30

what does an increase in VR mean for SV ?

Answer 30

increase in SV

Question 31

what do central effects do ?

Answer 31

allows us to increase our venous return

Question 32

what does more contractions lead to an increase in ?

Answer 32

increase in VR and increase in SV

Question 33

what does it mean when theres an increase in SV ?

Answer 33

more blood to heart

Question 34

why does HR increase ?

Answer 34

because we have an increase in sympathetic nervous system drive to the heart

Question 35

over time which organs decrease blood circulation to focus more on muscles during increased activity ?

Answer 35

GI tract organs (stomach, liver, etc)

Question 36

what are the two muscle pump effects ?

Answer 36

central and peripheral

Question 37

what do peripheral effects do ?

Answer 37

muscle contraction increases arterial flow (mechanical)

Question 38

what term pumps our blood away faster ?

Answer 38

peripheral effects

Question 39

at any pressure, flow through blood vessels is regulate by modifications in what ?

Answer 39

local vascular resistance

Question 40

what are the three types of arterioles (in regards to diameter) ?

Answer 40

- vasoconstriction - normal arteriole - vasodilation

Question 41

define vasoconstriction :

Answer 41

reduce radius and increase resistance

Question 42

define vasodilation :

Answer 42

increase radius and decrease resistance

Question 43

between vasoconstriction and vasodilation which is non-active tissue ?

Answer 43

non-active tissue = vasoconstriction

Question 44

between vasoconstriction and vasodilation which is active tissue ?

Answer 44

vasodilation

Question 45

how many things are there in regards to the diversion of blood flow ?

Answer 45

5

Question 46

between the 5 things in regards to the diversion of blood flow; how many are vasoconstriction and how many vasodilation ?

Answer 46

vasoconstriction = 2 vasodilation = 3

Question 47

describe the three vasodilation factors in regards to the diversion of blood flow :

Answer 47

- vasodilator formation in skeletal muscle - flo-induced vasodilation - myogenic vasodilation

Question 48

describe the two vasoconstriction factors in regards to the diversion of blood flow :

Answer 48

- sympathetic vasoconstriction - circulating vasoconstrictors

Question 49

what innervates the smooth muscle in arterioles ?

Answer 49

the sympathetic nervous system

Question 50

is the baseline sympathetic activity always on ? yes or no ?

Answer 50

yes always on

Question 51

what is the vasomotor tone ?

Answer 51

the end result of a complex set of interactions that control relaxation and contraction of blood vessels

Question 52

an increase in sympathetic activity leads to an increased or decreased vasoconstriction ?

Answer 52

increased vasoconstriction

Question 53

a decrease in sympathetic activity leads to an increased or decreased vasoconstriction ?

Answer 53

decreased vasoconstriction

Question 54

what is another term for passive vasodilation ?

Answer 54

vasoconstriction

Question 55

what does an increase (more impulses) of sympathetic activity lead to in regards of NE and neurotransmitters ?

Answer 55

more NE and neurotransmitters to the smooth muscles

Question 56

where does sympathetic activity come from ?

Answer 56

coming from the CNS

Question 57

what innervates the adrenal medulla ?

Answer 57

the sympathetic nervous system

Question 57

TRUE OR FALSE vasoconstriction doesn't cause smooth muscle relaxation

Answer 57

TRUE

Question 58

does an increase in sympathetic activity increase or decrease catecholamine release ?

Answer 58

increases

Question 59

what are two catecholamines ?

Answer 59

NE and Epi

Question 60

what does increased circulating epinephrine and norepinephrine lead to ?

Answer 60

- increased vasoconstriction non-active tissues - increased HR and contractility - increased glycogenolysis and glycogenesis (liver and muscle)

Question 61

what does increased vasoconstriction of non-active tissues mean for dilation in muscle ?

Answer 61

it means that areas that need more blood will get it

Question 62

when we don't want / need blood what does the body do ?

Answer 62

vasoconstriction

Question 63

why do we have glycogenolysis near the muscles ?

Answer 63

to keep glucose stores close to where it is needed

Question 64

describe the pathway of vasoconstriction control :

Answer 64

- hypothalmus - nerve impulses - spinal cord - adrenal medula - catecholamines (Epi and NE)

Question 65

what does increase catecholamine release (due to increased sympathetic activity) lead to (in regards to blood vessels ?

Answer 65

vasoconstriction of non-active tissues

Question 66

what does MSNA stand for ?

Answer 66

muscle sympathetic nerve activity

Question 67

what does splanchnic mean ?

Answer 67

organs in abdominal cavity

Question 68

in regards to the formula for resistance what is the most important factor ?

Answer 68

radius

Question 69

is intrinsic control the constrictor or dilator side ?

Answer 69

dilator side (vasodilator control)

Question 70

how many types of intrinsic control are there ?

Answer 70

3

Question 71

name the three types of intrinsic control :

Answer 71

- metabolic - endothelial - myogenic

Question 72

define metabolic intrinsic control :

Answer 72

chemical agents released as consequence of metabolism directly on smooth muscle

Question 73

define endothelial intrinsic control :

Answer 73

dilator substances produced within endothelium of arterioles in response to various stimuli

Question 74

what is endothelium ?

Answer 74

the inner lining of arterioles

Question 75

the following is seen in what type of intrinsic control ? nitric oxide, prostaglandins, endothelium-derived hyper polarizing factor

Answer 75

endothelial

Question 76

the following is seen in what type of intrinsic control ? increased CO2, K, H and lactic acid

Answer 76

metabolic

Question 77

define shear stress :

Answer 77

when we increase that release of nitric oxide from the endothelial cell & nitric oxide has a basal relaxation/vasodilation effect on the smooth muscle

Question 78

what does increased flow within endothelial intrinsic control do ?

Answer 78

helps get O2 rich blood to where it is needed

Question 79

is nitric oxide a vasodilator or vasoconstrictor ?

Answer 79

vasodilator

Question 80

does nitric oxide work very fast or very slow ?

Answer 80

very fast

Question 81

does "sheer stress" mean a greater or lower interaction of RBC on the all of the endothelial ?

Answer 81

greater

Question 82

define myogenic intrinsic control :

Answer 82

pressure changes within the vessels themselves can cause smooth muscle constriction or relaxation

Question 83

what between the three intrinsic controls increases during exercise because there is an increased pressure on the outside of the vessel wall leading to dilation ?

Answer 83

myogenic