The circulatory system

Question 1

Continuous capillaries

Answer 1

intercellular clefts
Skin, muscle, lungs, CNS
Allows fluid and small solutes to enter/exit intercellular clefts

Question 2

Fenestrated capillaries

Answer 2

Pores - fenestrations
Kidney, small intestine, endocrine glands
Filtration, absorption or secretion

Question 3

Sinusoidal capillaries

Answer 3

Large fenestrations and spaces between - sinusoids
Liver, lymphoid, bone marrow, adrenal medulla
Very leaky - allow large proteins to enter/exit

Question 4

Blood pressure

Answer 4

Force exerted on a vessel wall by the blood in that vessel

Question 5

Mean arterial pressure MAP

Answer 5

Pressure that propels blood through the vessels
Declines with increasing distance to heart
Equation = Diastolic pressure (⅓ pulse pressure)

Question 6

Pulse pressure

Answer 6

Systolic pressure - diastolic pressure

Question 7

Arterial blood pressure

Answer 7

How much elastic artery can be stretched - compliance

Question 8

Regulation of blood pressure

Answer 8

1. Autoregulation
2. Neural regulation
3. Renal regulation
4. Endocrine regulation

Question 9

Cardiac output to control BP

Answer 9

Rapid, short term regulation of BP and blood flow
determines blood pressure

Question 10

Resistance to control BP

Answer 10

Peripheral resistance rapid, short term regulation of BP and blood flow
Change arterial diameter

Question 11

Blood volume to control BP

Answer 11

Slower, long term regulation of BP
Controlled by renal and endocrine mechanisms

Question 12

Autoregulation

Answer 12

Occurs within tissues
Altering arteriole diameter to regulate blood flow into capillary beds
Metabolic control - Co2 O2 and pH
Myogenic (muscle) control and reduced stretch