hemodynamics 2

Question 1

systolic pressure

Answer 1

peak aortic pressure

Question 2

diastolic pressure

Answer 2

minimun aortic pressure

Question 3

blood pressure is expressed as

Answer 3

systolic/diastolic

Question 4

Pulse pressure =

Answer 4

Psys – Pdias = 120 – 80 = 40 mmHg

Question 5

Mean arterial pressure (MAP)=

Answer 5

~ Pdias + ⅓(Psys – Pdias) = 80 + ⅓(40) = 93 mmHg

approximate because it depends on heart rate

Question 6

Pulse pressure, mean pressure, and velocity all _____ through the vasculature.

Answer 6

decrease

Question 7

C (vascular compliance) =

Answer 7

C= ΔV / ΔP

C= compliance
V is volume
P is pressure

Question 8

compliance represents the

Answer 8

elastic properties of the vessels or chambers

Question 9

compliance of arteries

Answer 9

absorbs energy and transforms pulsatile flow to continuous flow

Question 10

____ are more compliant

Answer 10

veins are more compliant that arteries

Question 11

compliance is determined by

Answer 11

relative properties of elastin versus smooth muscle and collagen in vessel walls

Question 12

arteriosclerosis

Answer 12

when vessels lose compliance with age

older people have higher systolic pressure and higher pulse pressure than younger people

Question 13

Law of LaPlace represents the

Answer 13

relationship between wall tension and transmural pressure

Question 14

Law of LaPlace equation

Answer 14

T = (ΔP x r) / u

T is wall stress/tension
P is Transmural pressure
r is radius
u is wall thickness

Question 15

tension in the wall increases as

Answer 15

pressure and radius increase

Question 16

walls of larger vessels are subject to

Answer 16

greater tension

Question 17

hypertension increases

Answer 17

stress on walls of vessels and chambers

Question 18

an aneurysm increases

Answer 18

the radius of the vessel and thus increases the stress on the wall. This is why it can lead to a rupture or dissection

Question 19

Law of LaPlace in the heart chambers

Answer 19

1. decreased wall thickness causes an increased tension

2. increased radius causes an increased tension

Question 20

Cardiovascular transport occurs by

Answer 20

1. bulk transport

2. transcapillary transport

Question 21

Bulk transport

Answer 21

refers to movement of a substance through the cardiovascular system from point A to point B

Question 22

Transcapillary transport

Answer 22

describes the movement of a substance between capillaries and tissue

Question 23

bulk transport equation

Answer 23

x = Q • [x]

x = rate of transport of substance x
Q= flow 
[x]= concentration of substance x

Question 24

how much O2 carried to a muscle in a minute?

Answer 24

Delivery in ml O2/min = cardiac output x O2 concentration

Question 25

Fick's principle is the

Answer 25

application of the bulk transport idea to substrate consumption by a capillary bed, a tissue, or the whole body. simple conversion of mass: amount used is the amount in minus the amount out

Question 26

Fick's equation

Answer 26

``` Xused = Xi - Xo Xused = (Q •[x]i) - (Q •[x]o) Xused= Q ([x]i - [x]o) ```

Question 27

Q is constant through

Answer 27

CV system, so it is the same for initial and final conditions.

Question 28

Fick’s Principle is commonly used to determine

Answer 28

cardiac output and myocardial O2 consumption

Question 29

Ficks equation for myocardial oxygen consumption

Answer 29

mVo2 = CO ([O2]a - [O2]v) ``` mVo2 = myocardial oxygen consumption (ml/min) CO = cardiac output (L/min) [O2]a = arterial O2 concentration [O2]v = venous O2 concentration ```

Question 30

Fick's equation for cardiac output

Answer 30

CO = mVo2/ ([O2]a - [O2]v)