Midterm 1 - Blood Vessels and Blood Pressure

Question 1

important factors of blood pressure in blood vessels

Answer 1

diameter
elasticity
contractility

Question 2

what blood vessel is the target to regulate pressure

Answer 2

arteriole

Question 3

how does an edema occur

Answer 3

no venous return, blood sits in capillaries and fluid builds

Question 4

flow

Answer 4

volume of fluid transported per time unit

Question 5

what is flow between 2 points dependent on

Answer 5

pressure difference between the 2 points and resistance to fluid

Question 6

how to calculate flow (Q)

Answer 6

pressure difference/resistance

Question 7

is pressure higher in arteries or veins

Answer 7

arteries

Question 8

what are arterioles

Answer 8

the “bottlenecks” of the circulation

Question 9

why are arterioles the main site of pressure/flow regulation

Answer 9

they have the most smooth muscle

Question 10

what does initial pressure result from

Answer 10

heart contraction

Question 11

does pressure progressively increase or decrease

Answer 11

decrease

Question 12

what does resistance depend on

Answer 12

length of vessel
radius of vessel
blood viscosity

Question 13

what is constant in an individual

Answer 13

the length of vessel

Question 14

what is the most important factor for resistance

Answer 14

radius of vessel

Question 15

why is radius so important for resistance

Answer 15

resistance decreases by the 4th power of the radius: if the radius increased 2 times, resistance decreases 16 times

Question 16

what does viscosity of blood vary with

Answer 16

cells and proteins amount

Question 17

what occurs during ventricular contraction when aortic valves open

Answer 17

rapid flow of blood
increased arterial pressure
some pressure is absorbed by aorta elasticity

Question 18

what does aorta elasticity do with pressure

Answer 18

temporarily stores energy like a rubber plastic

Question 19

what occurs during diastole when the aortic valve closes

Answer 19

no blood flowing from ventricle
stored energy is released
allows blood flow to continue in vessels
gradual decrease in arterial pressure

Question 20

what are compliant

Answer 20

arteries

Question 21

what does the elasticity and large diameter of arteries supply

Answer 21

low resistance
high flow

Question 22

what does the recoil of wall of artery limit

Answer 22

the drop in pressure after systole

Question 23

how can a difference in arterial blood pressure be observed

Answer 23

between systole pressure and diastole pressure

Question 24

pulse pressure

Answer 24

difference between systolic and diastolic pressure

Question 25

what occurs to the mean blood pressure during rest

Answer 25

MBP closer to diastolic pressure (diastolic lasts longer than systole)

Question 26

what occurs to the mean blood pressure during exercise

Answer 26

MBP closer to systolic pressure (heart rate increased = diastole shortened)

Question 27

what is pulse pressure the measure of

Answer 27

measure of pressure on artery wall during systole

Question 28

factors influencing arterial pressure

Answer 28

elasticity of artery cardiac output respiration resistance to blood flow blood volume

Question 29

what is the main factor influencing arterial pressure

Answer 29

resistance to blood flow

Question 30

what influence does aging have with elasticity of artery

Answer 30

low elasticity = high pressure

Question 31

what influence does more blood from systole have on pressure

Answer 31

more blood = increased pressure

Question 32

what occurs during inspiration

Answer 32

low pressure in thoracic cavity, high pressure in abdominal cavity

Question 33

what does the pressure occurring during inspiration promote

Answer 33

venous return

Question 34

what does total peripheral resistance depend on

Answer 34

vasoconstriction of arterioles. increase in TPR = increase pressure

Question 35

what does blood volume influence

Answer 35

cardiac output

Question 36

why does blood volume have minimal effect on cardiac output

Answer 36

vein absorb the major effect

Question 37

what is unique about arteriole walls

Answer 37

they have fewer elastic fibers but larger number of smooth muscle fibers

Question 38

what is the basal level of constriction

Answer 38

myogenic (basal) tone

Question 39

what does the myogenic tone make possible

Answer 39

to decrease and increase vessels contraction thus diameter

Question 40

what happens too resistance when diameter decreases

Answer 40

resistance increases

Question 41

what are the 2 levels of control of arteriolar resistance

Answer 41

autoregulation (local mechanisms) extrinsic control factor (neuro-hormonal)

Question 42

what does auto regulation do within organ or tissue

Answer 42

overrides extrinsic regulation

Question 43

what does autoregulation control

Answer 43

flow to critical organs = protective mechanism

Question 44

types of autoregulation

Answer 44

metabolic regulation myogenic (pressure) regulation

Question 45

what does metabolic regulation respond to

Answer 45

changes in metabolism, thus blood requirement

Question 46

what does metabolic regulation increase in

Answer 46

diameter (decrease in pH, increase in CO2, K+, NO)

Question 47

what does the relative importance of factors in metabolic regulation depend on

Answer 47

the organ

Question 48

what does myogenic auto regulation entail

Answer 48

vessels respond to changes in tone or stretch

Question 49

what does myogenic autoregutalion maintain

Answer 49

the blood supply is virtually unchanged even when pressure changes

Question 50

how does autoregulation adapt

Answer 50

locally with specific organs to maintain function

Question 51

when is extrinsic regulation activated

Answer 51

when there is a problem

Question 52

what does extrinsic regulation regulate

Answer 52

the peripheral pressure as a whole

Question 53

what are the vasoconstrictive influences of extrinsic regulation

Answer 53

sympathetic stimulation on a-adrenergic receptors angiotensin II arginin vasopressin

Question 54

what is a vasodilatory influence of extrinsic regulation

Answer 54

parasympathetic stimulation (vagus nerve, mainly penis and clitoris)

Question 55

how low can pressure be when blood enters venous system

Answer 55

10 mm Hg

Question 56

what does the heart act as

Answer 56

a pump

Question 57

what kind of muscles do veins possess

Answer 57

smooth

Question 58

what occurs when pressure in veins is too high

Answer 58

flow is reduced and fluid leaks out and accumulates in tissue - edema

Question 59

how can skeletal muscle activity help with veins and venous pressure

Answer 59

it can help squeeze blood upward

Question 60

what side of the heart has higher pressure

Answer 60

right

Question 61

what happens to pressure during inspiration

Answer 61

P in thoracic cavity decreases P in abdonominal cavity increases

Question 62

main variables of controlling blood pressure

Answer 62

heart rate stroke volume TPR

Question 63

what contribute to blood pressure reflex

Answer 63

baroreceptors sensory fibers integration center motor fibers effectors

Question 64

what are baroreceptors

Answer 64

stretch receptors

Question 65

what do baroreceptors sense

Answer 65

stretching of arterial wall

Question 66

where are baroreceptors located

Answer 66

sensitive areas: aortic arch carotid sinus

Question 67

what do baroreceptors have

Answer 67

free nerve endings

Question 68

where do sensory fibers ascend

Answer 68

via vagus nerve

Question 69

what happens due to sensory fibers when stretch increases

Answer 69

increase in APs frequency

Question 70

what happens due to sensory fibers when stretch decreases

Answer 70

decrease in AP frequency

Question 71

what is the integration center

Answer 71

cardiovascular (vasomotor) center in the medulla oblongata

Question 72

what does the integration center do

Answer 72

compares info to reference value

Question 73

what are the effectors involved with controlling blood pressure

Answer 73

heart arterioles and vein

Question 74

example of baroreceptors in action

Answer 74

postural hypotension

Question 75

what is postural hypotension

Answer 75

change from lying to standing position

Question 76

what does the atrial volume receptor reflex

Answer 76

stretch receptors in wall of atria and regulate blood volume

Question 77

how does the atrial volume receptor reflex regulate blood volume

Answer 77

via autonomic nervous system activity neural input that controls this and the secretion of hormones that alter renal handling of sodium and water

Question 78

what are the stretch receptors in wall of atria

Answer 78

volume receptors

Question 79

what is atrial natriuretic peptide (ANP)

Answer 79

hormone synthesized in atrial wall

Question 80

what does ANP increase

Answer 80

sodium excretion

Question 81

what is renin

Answer 81

hormone synthesized in kidney which increases synthesis of angiotensin II to create aldosterone

Question 82

what are hormones involved in BP regulation

Answer 82

atrial natriuretic peptide renin antidiuretic hormone = vasopressin (post. pituitary)

Question 83

what does antidiuretic hormone vasopressin do

Answer 83

decrease water excretion in kidney - decrease water loss in urine

Question 84

what does angiotensin II do `

Answer 84

vasoconstriction

Question 85

what does aldosterone do

Answer 85

decrease sodium excretion

Question 86

what is vasoconstriction

Answer 86

when there is a drop in blood volume, decreases arterial going into kidney