Tissue fluid Flashcards
What is tissue fluid?
The fluid that surrounds cells in tissues.
What is tissue fluid made up of?
Small molecules (e.g. oxygen and water).
How do substances move in and out of the capillary bed?
By pressure filtration.
What happens at the 1st step of pressure filtration?
At the arteriole end of the capillary bed, hydrostatic pressure in capillaries is greater than in tissue fluid.
What happens at the 2nd step of pressure filtration?
The difference in hydrostatic pressure forces fluid out of the capillaries forming tissue fluid.
What happens at the 3rd step of pressure filtration?
As the fluid leaves, the hydrostatic pressure reduces in capillaries so hydrostatic pressure lower at venule end.
What happens at the 4th step of pressure filtration?
Due to fluid loss and an increasing conc. of plasma proteins, water potential at venule end is lower than in tissue fluid.
What happens at the 5th step of pressure filtration?
Some water re-enters capillaries at venule end by osmosis.
What happens to excess fluid?
Drained by lymphatic system.
What is the lymphatic system?
A network of vessels through which lymph drains from the tissues into the blood.
What is the role of the lymphatic system?
Collects the excess fluid and returns it back to the circulatory system.
What is lymphedema?
Swelling (usually in the legs) caused by lymph accumulating in the tissues in the affected areas.
What is lymphedema caused by?
An obstruction that does not allow proper drainage of lymph from the body tissue.
