Lecture 10: Overview of Circulation

Question 1

What is systolic arterial pressure in the systemic circulation?

Answer 1

120 mm Hg

Question 2

What is the diastolic arterial pressure in the systemic circulation?

Answer 2

80 mm Hg

Question 3

What is the pulmonary artery systolic pressure?

Answer 3

25 mm Hg

Question 4

What is the pulmonary diastolic pressure?

Answer 4

8 mm Hg

Question 5

What are the functional parts of the arteries?

Answer 5

arteries
arterioles
capillaries
venules 
veins

Question 6

What do the arteries do in circulation

Answer 6

transport under high pressure

Question 7

What do the arterioles do in circulation?

Answer 7

control conduits

Question 8

What do capillaries do in circulation?

Answer 8

exchange between blood and extracellular fluid

Question 9

What percent of blood volume is in the systemic circulation?

Answer 9

84%

Question 10

What percent of blood is in the veins?

Answer 10

64%

Question 11

What percent of blood is in the arteries?

Answer 11

13%

Question 12

What percent of blood is in the systemic arterioles and capillaries?

Answer 12

7%

Question 13

What percent of blood is in the heart and lungs?

Answer 13

16%

Question 14

What is the equation for velocity of blood flow?

Answer 14

V= F/A

F= volume of blood flow
A= cross sectional area

Question 15

Rate of blood flow to each tissue of the body is almost always precisely controlled in relation to what?

Answer 15

to the tissue need

Question 16

The cardiac output is controlled mainly by _______

Answer 16

sum of all the local tissue flows

Question 17

Arterial pressure regulation is generally independent of either ________ or _________

Answer 17

local blood flow

cardiac output control

Question 18

What is pressure gradient?

Answer 18

pressure difference between the two ends of a vessel

Question 19

What is resistance?

Answer 19

impediment to blood flow through the vessel

Question 20

Ohm’s law

Answer 20

F= change in pressure/ resistance

Question 21

What is the overall blood flow of an adult at rest?

Answer 21

5000 ml/min

Question 22

Laminar blood flow = _________ flow

Answer 22

streamline

Question 23

In laminar flow, the velocity of fluid flowing in center is _______ than that of fluid flowing towards outer edge

Answer 23

greater

Question 24

what is turbulent flow?

Answer 24

nonlayered flow

Question 25

Turbulent flow creates _____ and produces more _____ than laminar flow

Answer 25

murmurs; resistance

Question 26

When does turbulent flow occur?

Answer 26

when flow is too great
when blood passes an obstruction with the vessel
when blood has to make a sharp turn
when flood passes over a rough surface

Question 27

Tendency for turbulent flow increases in ______ proportion to velocity of blood flow

Answer 27

direct

Question 28

Tendency for turbulent flow increases in ______ proportion to diameter of the vessel

Answer 28

direct

Question 29

Tendency for turbulent flow increases in ______ proportion to density of the blood

Answer 29

direct

Question 30

Tendency for turbulent flow increases in ______ proportion to viscosity

Answer 30

inverse

Question 31

Laminar flow equation

Answer 31

Re= (vdp)/ n

v= mean velocity of blood flow
d= vessel diameter
p= density
n= viscosity

Question 32

What is Re?

Answer 32

Reynolds number, the measure for the tendency for turbulence to occur

Question 33

When Re rises above 200-400, turbulent flow will occur in _____ regions of a vessel

Answer 33

some

Question 34

When Re rises above 2000, turbulence will even occur in _____ vessels

Answer 34

straight

Question 35

What is blood pressure?

Answer 35

the force exerted by the blood against any unit area of the vessel wall

Question 36

What can pressure be measured with?

Answer 36

mercury manometer

electronic transducers

Question 37

What is resistance?

Answer 37

impediment to blood flow in a vessel

Question 38

What variable determine resistance?

Answer 38

vessel radius
blood viscosity
vessel length

Question 39

What is cardiac output?

Answer 39

rate of blood flow through entire circulatory system, 100 ml/sec

Question 40

What is the pressure difference from systemic arteries to systemic veins?

Answer 40

100 mm Hg

Question 41

In conditions when vessels are strongly constricted, total peripheral resistance may rise to _____

Answer 41

4 PRU

Question 42

When vessels are greatly dilated, the resistance can fall to as little as _____

Answer 42

0.2 PRU

Question 43

What is the mean pulmonary arterial pressure?

Answer 43

16 mm Hg

Question 44

What is the mean left atrial pressure?

Answer 44

2 mm Hg

Question 45

What is conductance?

Answer 45

measure of blood flow through a vessel for a give pressure difference

Question 46

conductance is ______ proportional to diameter

Answer 46

directly

Question 47

What is Poiseuille’s Law?

Answer 47

V = π p r4 / 8 η l

Question 48

What is the equation for resistance for blood vessels arrange in parallel

Answer 48

1/Rtotal= 1/R1 + 1/R2 +1/R3…..

Question 49

What does amputation of a limb or removal of a kidney do?

Answer 49

removes a parallel circuit:
reduces total vascular conductance
reduces total blood flow
increases total peripheral vascular resistance

Question 50

What circulations are arranged in parallel?

Answer 50

brain
kidney
muscle
gastrointestinal
skin
coronary circulation

Question 51

What is viscosity?

Answer 51

measure of the fluid’s internal resistance

Question 52

Greater the viscosity, ______ the resistance

Answer 52

greater

Question 53

What is the prime determinant of blood viscosity?

Answer 53

hematocrit

Question 54

Anemia _____ viscosity

Answer 54

decreases

Question 55

Polycythemia _____ viscosity

Answer 55

increases