formation of tissue fluid

How much of blood is plasma and what does plasma contain

55%

Dissolved glucose

Mineral ions

Proteins

Carries platelets

What percentage of. Blood is water

95%

What happens first when formating tissue fluid with the plasma and what does that cause tissue fluid to contain less of?

Some plasma leaks through fenestrations in capillary wall except large plasma proteins

Tissue fluid contains fewer proteins

Exchange substances pass through tissue fluid before it gets to cells/ blood

What does volume of liquid depend on

Hydrostatic pressure - pressure exerted by blood

Oncotic pressure - tendency of water to move into the blood by osmosis

Wat happens at the arterial end?

HS pressure is higher than osmotic (Blood pressure is high)

Exerts fluid out of blood vessel

Increased protein content in blood vessel lowers the WP

Creates osmotic pressure (conc gradient)

HP is greater so net movement of water is out

What happens at the venous end

HP decreases as fluid has moved out and pulse is completely lost

WP is same

O.P is higher than H.P

So net movement is water moves back in from tissue fluid

How much of blood goes back in and how much is left

90% of blood lost goes back in but 10% gets taken by lymph vessel

When can oedema occur

If B.P is higher (hypertension) - pressure at arterial end is greater

More tissue fluid outside and accumulates - oedema

What’s contained in tissue fluid

Same composition of plasma without RBC and plasma proteins

What is a lymph

Closed ends

Large pores to allow large molecules to pass

What is contained in a lymph

Less oxygen and nutrients than plasma and tissue fluid

Contains fatty acids - from villi in smal intestine

How do the lymph’s work

Opening are small valves in vessel walls (entry to lymphatic system)

Liquid moves along larger vessels by compression cause by body movement

Lymph returns to blood flowing under clavicle and collar bone

Escaped plasma proteins are now returned via lymph capillaries

What are lymph nodes and here are they?

Along lymph vessels are lymph nodes where lymph nodes build up (antibiotic production )

Enlarged lymph nodes - sign body is fighting off infection