3-Hemodynamics

Question 1

laminar flow

Answer 1

streamlined, efficient flow
-parabolic bc slower/more friction/resistance close to vessel wall + highest velocity in middle

Question 2

turbulent flow

Answer 2

irregular eddy currents with more shear stress on endothelial cells
-more energy to move blood
-thrombi more likely to devel

Question 3

most important factor driving turbulent flow

Answer 3

velocity

blood flow = cross section area x velocity

Question 4

atherosclerosis

Answer 4

narrowing vessels from plaque build up
-from turbulent flow
-hear bruits

Question 5

law of laplace

Answer 5

wall tension = (transmural pressure x vessel radius) / wall thickness

Question 6

inc wall tension from

Answer 6

transmural pressure + radius

Question 7

thicker walls = ? tension

Answer 7

wall thickness dec wall tension bc better able to withstand

Question 8

wall tension balanced by

Answer 8

elastic + smooth muscle in vessels

if mismatch then rupture/aneurysm

Question 9

aneurysm

Answer 9

wall tension inc as vessel radius inc + transmural pressure inc = rupture

can be undetectable with just inc wall tension and radius until the pressure maximizes

Question 10

most prominent effect on flow

Answer 10

vessel radius

Question 11

artery structure

Answer 11

large lumen + thick walls

Question 12

arterioles structure

Answer 12

small lumen + thick innvervated wall

Question 13

capillaries structure

Answer 13

smallest lumen + very thin walls (1 cell)

Question 14

venules structure

Answer 14

small lumen + thin walls

Question 15

vein structure

Answer 15

large lumen + thick walls

Question 16

arterials as resistors

Answer 16

small changes in volume = large shift in pressure

Question 17

venous as capacitors

Answer 17

small changes in pressure = large shift volume

Question 18

venous compartment

Answer 18

largest volume of blood
-pressure direct to blood amount

if veins constrict then more vol pushed into circulation back to heart (symp stim)

Question 19

flow =

Answer 19

change in pressure / resistance

direct relation, move same direction

Question 20

if constant flow then ? velocity

Answer 20

velocity dec as total cross sectional area inc

why aorta has highest velocity bc smallest total cross section

Question 21

where pressure drop is greatest

Answer 21

across arteriolar compartment, corresponds with inc resistance

Question 22

arteriolar vasodilation = ? flow

Answer 22

inc capillary pressure and blood flow

Question 23

arteriolar vasoconstriction = ? flow

Answer 23

dec capillary pressure and blood flow
-inc afterload in LV

Question 24

resistance differences

L and R

Answer 24

left heart = systemic circulation resistance is 1 TPR
right heart = pulmonary circulation resistance is 0.1

total resist of systemic circ x10 higher than pulmonary

Question 25

velocity trends

Answer 25

1. highest in large arteries
2. drops dramatically as approach capillaries
3. rise slowly towards veins

Question 26

volume trends

Answer 26

1. highest in capacitor vessels of veins
2. lowest in high resistance structures (arterioles and caps)

Question 27

pressure trends

Answer 27

1. highest in arteries and arterioles
2. lowest in veins

Question 28

resistance trends

Answer 28

1. peaks in arterioles
2. low in arteries, caps, and veins