CVR 20 Capillaries

Question 1

Capillaries are composed of a single _____ cell rolled into a tube. They also have ____ which increase transport in the certain capillaries

Answer 1

Squamous cell

Fenestrations

Question 2

Differences between arterioles and capillaries are?

Answer 2

Arterioles - control distribution of blood flood, have sphincters, have ANS innervated smooth muscle

Capillaries - single endothelial cell and no smooth muscle but do have contractile elements

Question 3

Where is the least permeable and most permeabe cappillary structures?

Answer 3

continuous in the msucle lungs and skin

Discontinous in the bone marrow liver and spleen is most permeable.

Question 4

What type of EC is the BBB

Answer 4

continuous

Question 5

How much water moves between capillaries into interstitial space?

Answer 5

8 L/dau

Question 6

Filtration is ____ + ______

Answer 6

reabsorbtion plus bloodflow

Question 7

Plasma osmolarity is?

Answer 7

300 mosmols

Question 8

What causes colloid pressure (oncotic)

Answer 8

poorly diffusable protiens in plasma

Question 9

The starling hypothesis describe the _____ in ______ exchange.
It states that the cap walls are ____ to water but are ____ to proteins.
The forces determining exchange are _______, ________ and ________.

Answer 9

forces

capillary

leaky

relatively impermeable

gradient hydrostatic pressure

colloid osmotic pressure

filtration coefficent related to density and permability of caps.

Question 10

In the starling hypothesis what is K?

Answer 10

product of the permeability and the surface area of the the caps.

Question 11

Where does the gradient favour filtration?

Answer 11

glomerulus, than alveolii, than skeletal

Question 12

Oedema can occur when there is an _____ in cap _______ pressure. A decrease in ______. A ______ in cap permeability or an obrstruciton in the _______.

Answer 12

increase 
hydrostatic pressure
plasma oncotic pressure
increase 
lymphatics

Question 13

What causes the oedema which occurs in children suffering from protein calorie malnutrition?

Answer 13

The extreme lack of protein causes an osmotic imbalance in the gastro-intestinal system causing swelling of the gut diagnosed as an edema or retention of water.

Question 14

Explain the mechanisms underlying the oedema which
occurs in heart failure (HF). Differentiate between the oedema
evident in left vs right-sided heart failure

Answer 14

HF causes increase peripheral resistance and strain on heart damaging the myocardium.
Vasoconstricion causes fluid retention and increase hydrostatic pressure in caps. This shifts to favour interstitial fluid into tissue. Right sided heart starts in ankle or sacral.
Left sided damage begins in lungs.

Question 15

If arm blood flow is obstructed for more than about 30
secs during measurement of blood pressure, blood flow in
the arm is temporarily increased on release of the cuff due
to ONE of the following:
A. An increase in total peripheral resistance
B. Active hyperaemia
C. By a shifting of blood flow from other organs
D. By vasodilation resulting from build-up of local metabolites
E. By a temporary increase in mean arterial pressure

Answer 15

E