cardio 2.2

Question 1

what is the Ohm equation for flow

Answer 1

Q=DP/R (diastolic pressue, resistance)

Question 2

how is blood flow driven

Answer 2

pressure differences (gradients)

Question 3

what is poiseuille’s law

Answer 3

R=8VL/pr^4
V=velocity
L - vessel length
r= vessel radius
p=Pie

Question 4

what has the greatest infuence on resistence

Answer 4

Radius

Question 5

define blood pressure

Answer 5

the force with which the blood is pushed against the walls of the blood vessels

Question 6

why does the blood pressure decrease through the curculation

Answer 6

distance from the heart

Question 7

systolic pressure

Answer 7

highest amount of pressure reached during ventricular constriction (first sound heard when measuring BP)

Question 8

Diastolic pressure

Answer 8

minimum amount of pressure just before ventricular ejection begins (last sound when checking blood pressure)

Question 9

what is the wind kessel effect

Answer 9

Storing of potential energy in the arterial wall to allow a more continuous blood flow as the heart is relaxing (diastolic runoff)

Question 10

Formula for Mean arterial Pressure and define

Answer 10

pressure that propels blood into tissue (avarage pressure in the cardiac cycle
MAP=2/3 DP + 1/3 SP

Question 11

what is Total periperal resistance

Answer 11

the sum of all resistance in the vasculature

Question 12

what are three factors that increase resistance in a single vessel

Answer 12

• blood viscosity
• -vessels length (only constant
• vessel Diameter

Question 13

what does blood viscosity depend on

Answer 13

• concentration of suspended meduim (formed elements)
• velocity of flow
• radius of the vessel

Question 14

what occurs in low hematocrit states (ie Anemia)

high state?

Answer 14

viscosity decreases and

vascular resistance decreases

Question 15

what could the RBC do to increase viscocity

Answer 15

aggregate into stacks called rouleaux formation (thick blood)

Question 16

how much will the blood flow increase if the vessel dialates twice its radius

Answer 16

16 Fold (4x increase radius = 256 fold increase flow)

Question 17

what occurs in Venoconstriction

Answer 17

pressure increses more then resistance —->blood flow increases—–>venous return increases

Question 18

where are bororeceptors placed

Answer 18

in th carotid sinus and aortic arch (measure pressure)

Question 19

can bororeceptor change to BP

Answer 19

not, they do participate in baroreceptor reflex (tell the body what the blood pressure is)

Question 20

Baroreceptor communicate with what

Answer 20

CNs IX and X, which carry the signal to the medullarty cardiovasular (aka cardioregulatory) center in the brain

Question 21

how does the medullary cardiovasular center function

Answer 21

• consist of individual muni-center such and the vasomotor are and cardioinhibitory area
• makes desisions about what to do about hypertension and hypotension
• and then employs services using SNS and ParaNS

Question 22

what occurs when the blood pressure is to high

Answer 22

deacrease in SNS activity and increase in PNS activity to lower HR

Question 23

what occurs when the blood pressure is to low

Answer 23

Increase in SNS activity and decrease in PNS activity to rais HR

Question 24

what occurs to blood pressure when you get out of bed

Answer 24

blood pressure rises

Question 25

what are the limitation to baroreceptors

Answer 25

Can not correct extreem hypo and hypertension issues

Question 26

what is a common example of a baroreceptor reflex slowing down

Answer 26

orthostatic hypotension, slow baroreceptor reflex