blood pressure and capillary function

Question 1

left side of the heart

Answer 1

high pressure system approx 120/80 mmHg

Question 2

right side of heart

Answer 2

low pressure system 25/10 mmHg

Question 3

blood vessels are said to be…

Answer 3

1 elastic is disstensible (able to swell)
2conductive as large arteries 1 and 2 sum to 11% of volume
3resistive as large arterioles as these resist flow
4distributive as capillaries…3 and 4 account for 7% of volume
5capacatitive as veins …make up 70% of volume
6 heart and pulmonary circulation make up 22% of volume

Question 4

capillary beds

Answer 4

normally in parallel with resistances adding in parallel as reciprocals

unusually they are in series and their resistances are summed e.g. in hepatic portal

Question 5

aorta

Answer 5

pressure 120/80 mmHg

Question 6

arterioles

Answer 6

experience greatest fall in pressure from 75 down to 30 mmHg

Question 7

veins

Answer 7

pressure in veins is low

Question 8

vena cava

Answer 8

pressure is low and close to nil

Question 9

capillary recruitment

Answer 9

due to increased metabolism requires closed arterial veins shunts

Question 10

vasoconstriction

Answer 10

reduces hydrostatic pressure in capillaries and promotes fluid absorbtion

Question 11

vasodilatation

Answer 11

increased capillary pressure and promotes fluid production

Question 12

capillaries can be

Answer 12

a. continuous as in the cranial capillary beds Innervation
b. fenestrated (‘windowed’) to allow rapid fluid movement
c. Discontinuous with gaps with no fenestral membranes across them

Question 13

kfx

Answer 13

the capillary filtration coefficient