transfer of materials between in the circulatory system

Question 1

why do red blood cell, platelets, plasma proteins and most white blood cells remain the blood ?

Answer 1

they are too large to he pushed through the gaps

Question 2

what is a tissue fluid ?

Answer 2

the fluid which leaves the blood consists of plasma with dissolved nutrients and oxygen

Question 3

explain the effects of hydrostatic pressure and oncotic pressure ?

Answer 3

• as the blood moves along the capillary towards the venule end, hydrostatic pressure falls
• the water potential in the blood is lower due to the higher concentration of plasma proteins left in the capillary, therefore water moves back into the capillary by osmosis - oncotic pressure

Question 4

what is the lymphatic system ?

Answer 4

made up of lymph vessels which allow tissue fluid to flow into them at low pressure via one way valves - like veins

Question 5

how much of the fluid leaks out of the capillaries at the arterial end and what does it do after ?

Answer 5

90 % which seeps back in at the venous end

Question 6

where is the remaining 10 % returned to the blood by ?

Answer 6

lymphatic system

Question 7

what happens of the B.P increases (hypertension) ?

Answer 7

more fluid is forced out
the fluid accumulates in the tissues causing oedema

Question 8

describe how tissue fluid is formed ?

Answer 8

• left ventricle contracts causing hydrostatic pressure in the capillary
• fluid consisting of water and solutes are pushed out through the permeable capillary