22 Circulation

Question 1

9% of total blood flow. Site of oxygen and carbon dioxide exchange. Low pressure system

Answer 1

Pulmonary circulation

Question 2

Transports blood to tissues under high pressure (100 mmHg)

Answer 2

Aorta

Question 3

Arranged this way so that each organ system (GI, Muscle, Liver, etc) gets a stable blood supply (if the GI system is not functioning, the blood flow to the other systems is not affected)

Answer 3

Parallel arrangement

Question 4

Aorta, artery, arterioles, and capillaires appear in that order all the time

Answer 4

Serial arrangement

Question 5

aka resistance vessels. Have large amounts of smooth muscle. Also have a large diameter. Part of the high pressure system

Answer 5

Arteries

Question 6

aka conduit vessels
	Control site for blood flow
	Major resistance site of circulation
	Smaller diameter than arteries
	Have a higher proportion of smooth muscle in the wall than arteries (to provide resistance to blood flow, lowering local BP)

Answer 6

Arterioles

Question 7

Aka exchange vessels. Major site of water and solute exchange b/t blood and tissues.

Answer 7

Capillaries

Question 8

aka capacitance vessels. 64% of the blood in the body is found in veins & venules
 Returns bood to heart
 Under low pressure
 Serves as a reservoir of blood

Answer 8

Veins & venules

Question 9

Review all formulas & images

Answer 9

Do it

Question 10

o High pressure in the arterial tree
o Low pressures in the venous side of the circulation
o Large pressure drop across the arteriolar-capillary junction

Answer 10

BP profile of circulatory system

Question 11

Mainly controlled by local tissue flow

Answer 11

Cardiac output

Question 12

Controlled independent of either local blood flow control or cardiac output control

Answer 12

Arterial pressure

Question 13

___ to tissues is controlled in relation to tissue needs (parallel arrangement aids in this)

Answer 13

Blood flow

Question 14

o Blood usually flows in streamlines with each layer of blood remaining the same distance from the wall. This type of flow is called ___

Answer 14

Laminar flow. Note: When laminar flow occurs, the velocity of blood in the center of the vessel is greater than that toward the outer edge creating parabolic profile

Question 15

	High velocities
	Sharp turns in the circulation
	Rough surfaces in the circulation
	Rapid narrowing of blood vessels
Are all causes of \_\_\_

Answer 15

Turbulent blood flow

Question 16

T/F. Laminar flow is silent, whereas turbulent flow tends to cause murmurs

Answer 16

True

Question 17

___ or bruits are important in diagnosing vessel stenosis, vessel shunts, and cardiac valvular lesions

Answer 17

Murmurs

Question 18

Measure of the tendency for turbulence to occur
 When the RBC count is low, the ___ increases
 We will not be asked to calculate ___, but we will need to interpret it (i.e. if given a value for ___, be able to say if turbulent flow or laminar flow is occurring)

Answer 18

Reynold’s number

Question 19

The force exerted by the blood against any unit area of vessel wall. o Low pressures are sometimes reported in units of mmH20 (mm of water)
o 1mmHg = 13.6 mm of water

Answer 19

Blood pressure

Question 20

The overall resistance to flow through the entire systemic circulation

Answer 20

Total peripheral resistance

Question 21

: The CSA of ___ is 1000 times higher than the aorta

Answer 21

Capillaries