Cardio Lec 8

Question 1

Factors affecting resistance

Answer 1

tube length (fixed) & viscosity (thickness)

Question 2

An increase in tube length or viscosity __ flow

Answer 2

decrease

Question 3

Can blood viscosity change?

Answer 3

yes; (in polycythemia & anemia)

Question 4

Most important regulator of blood flow

Answer 4

diameter & MAP

Question 5

Small changes in vessel radius have large effects on resistance & flow

Answer 5

t

Question 6

As vessel length or blood viscosity go up -> resistance will go

Answer 6

up

Question 7

As vessel radius goes up -> resistance will go

Answer 7

down

Question 8

By doubling radius, you DECREASES resistance by

Answer 8

a factor of 16 -> INCREASE flow by a factor of 16

Question 9

Flow is the __ of resistance

Answer 9

inverse

Question 10

as pressure gradient goes up blood flow goes

Answer 10

up

Question 11

as the radius is increased blood flow goes

Answer 11

up

Question 12

as vessel length increases blood flow goes

Answer 12

down

Question 13

as viscosity increases blood flow goes

Answer 13

down

Question 14

Blood viscosity doesn’t change in healthy individuals

Answer 14

t

Question 15

Velocity measured by

Answer 15

distance per time

Question 16

Flow measured by

Answer 16

volume per time

Question 17

Which vessels have the largest cross sectional area & therefore slowest velocity of blood movement

Answer 17

capillaries

Question 18

Which vessel has the smallest cross sectional area & therefore the greatest velocity

Answer 18

aorta

Question 19

Arterioles aka

Answer 19

resistance vessels

Question 20

Arterioles act like a

Answer 20

clamp

Question 21

Total peripheral resistance =

Answer 21

sum of all vascular resistances w/in systemic circulation

Question 22

Stress causes tpr to go

Answer 22

up

Question 23

Tpr main determinant of

Answer 23

afterload

Question 24

Bp resistance greatest in

Answer 24

arterioles

Question 25

Pressure & flow reduced most in

Answer 25

capillaries (have smallest diameter)

Question 26

BP =

Answer 26

CO x TPR

Question 27

What organ control blood vol

Answer 27

kidneys

Question 28

Baroreceptors detect

Answer 28

stretch/pressure

Question 29

Baroreceptor reflex

Answer 29

maintain relatively constant pressure on a min by min basis

Question 30

How do baroreceptors respond to bp elevation

Answer 30

fire more to inhibit SNS -> lower bp

Question 31

How do baroreceptors respond to bp drop

Answer 31

fire less -> SNS more active -> bp rises

Question 32

Valsalva maneuver used to break

Answer 32

SVT

Question 33

Pulse pressure refers to

Answer 33

diff between systolic & diastolic (ex: 120/180=40)

Question 34

Myoglobin

Answer 34

binds 02 when 02 levels are high but doesn't release its 02 until levels are dangerously low

Question 35

Aortic compliance decreases greatly w/ age, systolic press gets higher & diastolic gets lower & pulse pressure gets bigger w/ age

Answer 35

t

Question 36

MAP =

Answer 36

diastolic press + 1/3 (pulse pressure) -> Ex: 120/90 -> 90 + 1/3 (30) = 90+10= 100 mmHg

Question 37

TPR due to

Answer 37

alpha receptor stimulation

Question 38

myogenic mechanism: When bp goes up -> increased flow to brain -> to oppose..

Answer 38

cerebral vessels constrict (keeps flow the same)

Question 39

myogenic mechanism: When bp goes down -> decrease flow to brain -> to oppose..

Answer 39

vessels dilate (keeps flow the same)

Question 40

Myogenic control refers to

Answer 40

vessels regulate their own flow

Question 41

Reactive hyperemia

Answer 41

accumulated end products BC FLOW WAS DIMINISHED to an area

Question 42

Active hyperemia

Answer 42

BC TISSUES ARE MORE ACTIVE

Question 43

In both reactive & active hyperemia you get an increase in flow due to

Answer 43

accumulation of end products

Question 44

Cerebral flow remains constant due to the

Answer 44

myogenic mechanism

Question 45

Heart must use __ respiration

Answer 45

aerobic

Question 46

Alpha receptors

Answer 46

constriction & bind NE

Question 47

Beta receptors

Answer 47

dilate & bind Epi

Question 48

During exercise, as heart exceeds 180 bpm, CO will

Answer 48

fall due to reduction of filling time

Question 49

EDV decreases during exercise

Answer 49

f; increases

Question 50

Hypoventilation

Answer 50

co2 levels rise -> vessels dilate

Question 51

Hyperventilation

Answer 51

co2 levels fall -> vessels constrict

Question 52

Most active areas of brain receive most blood

Answer 52

t

Question 53

Most people have 2ndary htn

Answer 53

f; most have primary/essential htn

Question 54

We try to keep bp under

Answer 54

120/80