Circulation Part 2

Question 1

What is determined by the fick principal and the indicator dilution?

Answer 1

determination of flow

Question 2

What do venous occlusion plesthymography, doppler ultrasonic flowmeter and vascular flow cuffs have in common?

Answer 2

all contribute to determination of vessel flow

Question 3

What is the 3 port system of the Fick Principal?

Answer 3

Input blood concentration of substance x
Output blood concentration of substance x
Addition/removal of substance x from tissue (see fig 20-18 in Guyton)

Question 4

amount of substance per min divided by the AV difference is equal to what?

Answer 4

Flow

Question 5

T/F: Indicator dilution is based on conservation of mass.

Answer 5

true

Question 6

Indicator dilution

Answer 6

See figure 20-19

Question 7

What is distensibility?

Answer 7

the ability of a vessel to stretch (distend)

Question 8

What is compliance?

Answer 8

The ability of a vessel to stretch and hold volume

Question 9

What is associated with a small change in volume in systemic arteries?

Answer 9

a large change in pressure

Question 10

What is a large change in volume in systemic veins associated with?

Answer 10

a small change in pressure

Question 11

T/F:Systemic arteries are about 8X more distensible and 24 X more compliant than veins.

Answer 11

False; swap veins and systemic arteries

Question 12

Local blood flow is regulated in proportion to what?

Answer 12

the metabolic demand in most tissues

Question 13

T/F: Short term control of blood flow involves changes in tissue vascularity.

Answer 13

False; this is true of long term control; short term control involves constriction/dilation of vessels

Question 14

Which type of control of blood flow is associated with vascular endothelial growth factor and angiotensin?

Answer 14

long term control

Question 15

T/F:Arterioles act as an integrator of multiple inputs regarding control of flow.

Answer 15

true

Question 16

T/F:Arterioles are richly innervated by SNS vasoconstrictor fibers and have beta receptors.

Answer 16

False; they have alpha receptors

Question 17

T/F: Short term Local control of flow involves vasoconstriction/vasodilation of precapillary resistance vessels.

Answer 17

True

Question 18

Explain the Local Vasodilator Theory.

Answer 18

Active tissue releases local vasodilator (metabolites) which relax vascular smooth muscle

Question 19

Explain Oxygen demand theory.

Answer 19

As tissue uses up oxygen, vascular smooth muscle cannot maintain constriction.

Question 20

Which is an older theory, local vasodilator theory of oxygen demand theory?

Answer 20

oxygen demand theory