Week 2: tuesday (hemodynamics and capillary function)

Question 1

which of the following could increase cardiac output (in healthy heart)
a.) increase afterload
b.) decrease end-diastolic volume
c.) increase preload
d.) increase parasympathetic activity
e.) decrease stroke volume

Answer 1

c. increase preload

Question 2

based on your understanding of heart sounds and blood flow through the heart, where on the phonogram would you hear a murmur from mitral valve incompetence

Answer 2

systolic murmur between S1 and S2

Question 3

based on your understanding of heart sounds and blood flow through the heart, where on the phonogram would you hear a murmur from PDA

Answer 3

continuous murmur

Question 4

where is pressure greater, arteriole or venous side

Answer 4

arteriole

Question 5

what is mean circulatory filling pressure

Answer 5

the pressure in the static circulation (~7 mmHg)

Question 6

what is the fundamental equation for flow

Answer 6

change in pressure/resistance

Question 6

what is the change in pressure across the systemic circuit

Answer 6

mean arterial pressure

Question 7

what is the change in pressure in the pulmonary circuit

Answer 7

pulmonary arterial pressure

Question 8

the pressure gradient in the systemic circuit is much greater than the pressure gradient in the pulmonary circuit, however, flow through both circuits is equal…

what can you conclude about resistence in the circuits?

Answer 8

higher resistance in systemic circuit

Question 9

what are factors affecting resistance to flow

Answer 9

1. radius of vessel
2. length of vessel
3. viscosity of fluid

Question 10

Q

Answer 10

flow

Question 11

P

Answer 11

pressure

Question 12

R

Answer 12

resistance

Question 13

n

Answer 13

viscosity

Question 14

L

Answer 14

length of tube

Question 15

r

Answer 15

radius of tube

Question 16

pi

Answer 16

3.14

Question 17

what is total peripheral resistance (TPR)

Answer 17

combined resistance of all blood vessels within the systemic circuit

Question 18

what is the subtituation equation for flow

Answer 18

CO = MAP/TPR

Question 18

large arteries have high elastin leading them to:

Answer 18

1. expand as blood enters during systole
2. recoil during diastole

Question 19

what is the consequence of the elasticity of the aorta

Answer 19

increased flow

Question 20

what is the dicrotic notch

Answer 20

brief increase in pressure in aorta when aortic valve closes

Question 21

what is pulse pressure

Answer 21

difference between systolic pressure and diastolic pressure

Question 22

what are three factors increasing pulse pressure

Answer 22

1. increased SV
2. decreased HR
3. decreased arterial compliance

Question 22

what is laminar blood flow

Answer 22

flow velocity increases from the wall to the central axis of the tube

Question 23

what is reynolds' number

Answer 23

predicts flow patterns in different flow conditions

Question 24

how is blood pressure recorded

Answer 24

systolic over diastolic

Question 25

arterioles provide resistance to ___ ___

Answer 25

blood flow

Question 26

more than ____% of total peripheral resistance is from arterioles

Answer 26

60

Question 27

how is resistance regulated

Answer 27

action on smooth muscle

Question 28

what is equation for velocity | capillaries

Answer 28

flow/area

Question 29

what are the two purposes of material across capillary walls

Answer 29

1. exhange materials between blood and cells 2. maintain normal distribution of extracellular fluid through filtration and absorption

Question 30

what is filtration

Answer 30

movement out of capillary into interstitial space

Question 31

what is absorption

Answer 31

movement into capillary from interstitial space

Question 32

what is hydrostatic pressure gradient

Answer 32

force due to blood pressure

Question 33

what is oncotic pressure

Answer 33

osmotic force of proteins

Question 33

what happens when fluid is shifted into the capillaries

Answer 33

* decreased intracapillary hydrostatic pressure * circulatory shock

Question 34

what happens when fluid is shifted into the interstitium (edema)

Answer 34

* increased intracapillary hydrostatic pressure * renal retention of Na and H2O (kidney failure) * high venous blood pressure (standing too long; heart failure)

Question 35

what are venules

Answer 35

* smaller than arterioles * connect capillaries to veins * little smooth muscle in walls * some exchange of material between blood and interstitial fluid

Question 36

what do valves in veins allow

Answer 36

unidirectional blood flow

Question 37

what do veins function as

Answer 37

volume reservoir

Question 38

what are the two mechanisms of venous return

Answer 38

1. skeletal muscle pump 2. respiratory pump

Question 39

what are two factors that influence venous pressure and venous return

Answer 39

1. blood volume 2. venomotor tone

Question 40

what are the 3 things that increase in venomotor tone leads to

Answer 40

1. increased central venous pressure 2. decreased venous compliance 3. increase venous return

Question 41

what is the lymphatic system

Answer 41

* system of vessels, nodes, and organs * returns excess filtrate (lymph) to circulation * open system * has immune functions