Blood, Tissue Fluid & Lymph Flashcards
What can be found in blood?
Red blood cells
White blood cells & platelets
Plasma - composed of: gases, nutrients, ions, water, proteins, wastes
What is blood plasma
55% of blood
It’s made of water (95%), and as H2O is a good solvent, it’s good for transport
How does blood plasma lead to tissue fluid forming (short)
As blood passes through capillaries, some plasma leaks out through gaps in capillary cell walls, to surround the cells of the body, therefore, tissue fluid forms
What it’s tissue fluid?
E.g. composition
What is does
- similar composition to plasma, but T.F. = way less proteins (as proteins are too large to fit through gaps in through capillary walls, & so remind in the blood.
T. F. bathes almost all the cells of the body outside of the circulatory system
Therefore the exchange of substances between cells and the blood occurs via the tissue fluid
What does the amount of liquid that leaves the plasma to form tissue fluid depend on
- Hydrostatic pressure = the pressure exerted by a fluid
- Oncotic pressure - the osmotic pressure exerted by plasma proteins within a blood vessels: it usually pulls water into the circulatory system
What happens at the arterial end of the capillary during tissue fluid formation
What happens at the venous end of the capillary during tissue fluid formation
Extra details about tissue fluid formation in the capillary
Not all tissue fluid returns to the capillaries… only 90%
The excess 10% goes where?
To form what?
Drains into the lymphatic system
To form lymph
What is lymph
A colourless, yellow, pale, fluid similar to tissue, but containing more lipids
How does the lymphatic system drain into the circulatory system, near the vena cava
Via the thoracic duct
How does tissue fluid into the lymph system
Through valves & nodes
These valves are even large enough to allow large protein molecules to pass through
What would happen without the lymph system
You would die as the rate of water loss in the blood would be too high
This would lead to oedema, build up of tissue fluid
What does the lymphatic system consist of
