Circulation Part 1

Question 1

What is the main function of systemic circulation?

Answer 1

deliver O2 and remove CO2 and wastes

Question 2

What part of circulation is designed to carry blood under high pressure out to the tissue beds?

Answer 2

systemic arteries

Question 3

What parts of circulation act as control valves to regulate blood flow?

Answer 3

arterioles and pre capillary sphincters

Question 4

How thick are capillaries?

Answer 4

1 cell layer thick

Question 5

Where does exchange occur between tissue and blood?

Answer 5

capillaries

Question 6

What do venules do?

Answer 6

collect blood from capillaries

Question 7

What structures return blood to heart/dynamic storage?

Answer 7

systemic veins

Question 8

T/F: blood flow is proportional to metabolic demand.

Answer 8

True

Question 9

T/F; cardiac output is controlled by local tissue flow.

Answer 9

true

Question 10

T/F: Arterial pressure control is dependent on local flow or cardiac output.

Answer 10

False; arterial pressure is independent of local flow or cardiac output.

Question 11

how many layers of endothelium exist in blood vessels?

Answer 11

1

Question 12

What are the components of blood vessels?

Answer 12

endothelium, elastic tissue, smooth muscle, and fibrous tissue

Question 13

What vessel is composed moreso of smooth muscle, aorta or typical arteries?

Answer 13

typical arteries

Question 14

What vessel is composed more so of elastic tissue, aorta or typical arteries?

Answer 14

aorta

Question 15

What vesel is composed more so of fibrous tissue, aorta or typical arteries?

Answer 15

aorta, but its still more elastic tissue than fibrous.

Question 16

T/F: veins are pretty much equally composed of elastic fibers, smooth muscle, and fibrous tissue.

Answer 16

True

Question 17

What are capillaries composed of?

Answer 17

only endothelium

Question 18

What is Ohm’s Law?

Answer 18

-V=IR (analogous to deltaP=FR)

Question 19

Flow, Pressure gradient, resistance and Ohm’s Law are all components of what?

Answer 19

Hemodynamics

Question 20

What is the term for the volume of blood that passes a certain point per unit time (eg. ml/min)?

Answer 20

Flow (F)

Question 21

T/F: At a given flow, the velocity is inversely proportional to the total cross sectional area.

Answer 21

True F=velocityX

Question 22

T/F: Flow is inversely proportional to the change in Pressure and directly proportional to resistance.

Answer 22

False; vice-versa: F=deltaP/R

Question 23

The driving force of blood and the difference in pressure between two points, are both ways to define what?

Answer 23

Pressure gradient

Question 24

T/F: Pressure gradient is proportional to flow.

Answer 24

True

Question 25

What happens to resistance of flow when the pressure drops?

Answer 25

the resistance increases equally

Question 26

What kind of circuit is systemic circulation (predominately)?

Answer 26

parallel circuit

Question 27

What is usually solved for indirectly by measuring flow and deltaP?

Answer 27

Resistance

Question 28

What is TPR?

Answer 28

Total peripheral resistance

Question 29

What are the 3 advantages of systemic circulation being predominately parallel circuitry?

Answer 29

Independence of local flow control, minimizes TPR, and O2 rich blood supply to every tissue

Question 30

What is the term for internal friction of a fluid associated with the intermolecular attraction?

Answer 30

viscosity

Question 31

What is the viscosity of blood?

Answer 31

3

Question 32

Viscosity of plasma?

Answer 32

1.5

Question 33

Viscosity of water?

Answer 33

1

Question 34

What is mostly responsible for the viscosity of blood?>

Answer 34

RBCs

Question 35

what happens to blood viscosity when velocity is decreased?

Answer 35

increases

Question 36

T/F:Fibrinogen decreases flexibility of RBCs.

Answer 36

False, actually increases flexibility

Question 37

Cells can get stuck at constriction points momentarily. What does this do to the apparent viscosity?

Answer 37

increases

Question 38

What is Hematocrit?

Answer 38

% of packed cell volume (primarily RBCs)

Question 39

What is the normal range of hematocrit?

Answer 39

38-45%

Question 40

Streamline, silent, most efficient, and normal all describe what kind of flow?

Answer 40

Laminar

Question 41

Cross mixing, vibrational noise, least effective, and frequently associated with vessel disease (bruit) all describe what kind of flow?

Answer 41

Turbulent

Question 42

What does Reynold's number tell us?

Answer 42

the probability for turbulent flow (the great the R# the great the probability for turbulence)

Question 43

velocity*tube diameter*density/viscosity=?

Answer 43

Reynolds numbers | R# = vDp/n

Question 44

If R# is less than 2000 what kind of flow is it typically?

Answer 44

laminar

Question 45

If R# is greater than 3000 what kind of flow is it typically

Answer 45

turbulent

Question 46

T/F: Ultrasound is commonly used to determine velocity of flow.

Answer 46

true

Question 47

During Doppler Ultrasound, if RBCs are moving toward the transmitter and therefore compressing sound waves, what is happening to the frequency of returning waves?

Answer 47

increase (Doppler frequency shift)

Question 48

What kind of flow is a Broad band (ultrasound) associated with?

Answer 48

turbulent flow

Question 49

What kind of flow is a narrow band associated with?

Answer 49

laminar flow