3.2.4: Tissue fluid

Question 1

describe the composition of tissue fluid in comparison to plasma

Answer 1

tissue fluid has fewer proteins as proteins are too large to fit through gaps in the capillary walls

Question 2

what is hydrostatic pressure?

Answer 2

pressure exerted by fluid

Question 3

what is oncotic pressure?

Answer 3

osmotic pressure exerted by plasma proteins within a blood vessel

Question 4

what occurs at the arterial end of capillary?

Answer 4

the hydrostatic pressure is great enough to force fluid out of the capillary, proteins will stay in blood creating a water potential gradient (osmotic pressure) between capillary and tissue fluid, at the arterial end the HP is greater than the OP do net movement of water is out go capillaries into tissue fluid

Question 5

what occurs at the venous end of capillaries?

Answer 5

HP inside capillary is reduced due to increased distance from heart, the water pot. gradient between capillary and tissue fluid remains the same as arterial end, however at venous end the OP is greater than the HP and water flows back into capillaries from tissue fluid

Question 6

describe the formation of lymph

Answer 6

some tissue fluid enters the lymph vessels which are separate from the circulatory system. Larger molecules unable to pass capillary wall will also enter lymphatic system as lymphs.

Question 7

how is the composition of tissue fluid different to composition of plasma?

Answer 7

in plasma there is a higher concentration of glusoce, amino acids and plasma proteins.
in tissue fluid the water potential is greater.