compliance of arteries

Question 1

compliance

Answer 1

describes how easy it is to actually expand a blood vessel

arteries have less compliance because of their muscle layer

veins high compliance –> apply a low pressure to expand need a higher pressure to expand?

Question 2

arteries

Answer 2

thick layer of smooth muscle

when blood flows through these arteries and there is a force and pressure on the walls of those smooth muscle, it can resist the expansion, gives them the ability to recoil their expansion. when blood tries to expand arteries they don’t actually expand
when blood fills arteries they expand only by a tiny amount

a very high pressure and force is needed in order to expand the arteries

Question 3

veins

Answer 3

tunica media is very thin and has a thin layer of smooth muscle

when blood flows through veins, the blood exert pressure on veins walls and veins cannot push back. this increase the volume of their veins that can pass.

veins have a high compliance

makes sure there isn’t a build up of pressure in veins
expansion taken in place and pressure remains in a relatively low pressure

veins double in their size (200%) and can store much more of the blood volume than arteries

skeletal muscles push blood up the body

Question 4

formula of compliance

Answer 4

c = change in volume of blood vessel/ change in pressure between inside and out

a small pressure increase of 25 mm Hg will increase by 400% in veins, they easily expand

Question 5

distend

Answer 5

means to expand

Question 6

start of surgery

Answer 6

intubate, put to sleep, give muscle relaxers

give muscle relaxers

what were doing with the HL machine

when you’re in laminar flow it will change the compliance in the capillary beds and influence the exchange, have a greater chance of having edema.

on venous size, you arent have the skeltal muscles contract. wont be as efficient as when you’re in pulsatile flow

how we combat that is the blood/fluid itself is staying in the third spacing

Question 7

third spacing

Answer 7

the blood in circulation, as it goes to tissue, is making the tissue endeminous

Question 8

doing arterial CABG

Answer 8

can take lima, rima, radial artery out,

artery grafts are more pulsatile, veins are less pulsatile when doing grafts

Question 9

4 factors of cardiac output

Answer 9

1. heart rate
2. myocardial contractility
3. preload
4. afterload

Question 10

factors that control cardiac output

Answer 10

Cardiac Factors
- heart rate
- myocardial contractility

Coupling Factors
preload
afterload

Question 11

coupling factors

Answer 11

preload and afterload determine cardiac output

due to starling curve

Question 12

frank starling curve

Answer 12

relationship which reflects the dependence of cardiac output on preload (CVP or right atrial pressure)

Question 13

vascular function curve

Answer 13

Vascular function curve
Dependence of CVP on cardiac output
Depends on certain vascular system characteristics
- PVR
- arterial and venous compliance
- blood volume

Independent of the characteristics of the heart

independent of frank starling relationship

Defines changes in CVP evoked by changes in CO

CO is independent variable (stimulus)
CVP is dependent variable (response)

Question 14

essential components of the cardiovascular system

Answer 14

1. Pump: right and left side of heart and
   the pulmonary vascular bed
   - contractility
2. Peripheral resistance
   high resistance in microcirculation
3. Arterial (Ca) compliance
4. venous (Cv) compliance

Compliance is the increment of volume accommodated per unit change of pressure
C = V/P
change in volume/ change in pressure

Question 15

measuring peripherasl resistance

Answer 15

resistance is 20 x difference

Question 16

static pressure

Answer 16

pressure in the circulatory system in the absence of flow

Reflects the total volume of blood in the system and the overall compliance of the entire system

as pressures change they cant moved from left side of body to right side of body