1.7 Formation of tissue fluid and lymph Flashcards
What happens when blood passes through the capillaries?
Some plasma leaks out the gaps in the walls of the capillaries to surround cells in the body, forming the formation of tissue fluid consumption of plasma.
What is the high pressure known as at the end arteriole?
Hydrostatic pressure.
What does hydrostatic pressure force?
Forces blood plasma out of the capillary, causing water and dissolved substances in blood plasma out the capillary walls, into surrounding tissue causing tissue fluid.
What happens to the substances?
They are picked up by cells, and waste substances are deposited into the tissue fluid.
Given and example using oxygen and carbon dioxide.
Oxygen is absorbed by the cells from the tissue fluid for respiration, and carbon dioxide released by the cells will dissolve in the tissue fluid to be removed as waste.
Why does tissue fluid contain fewer proteins?
Because proteins are too large to fit through the gaps in the capillary walls so they remain in the blood.
What would happen if the fluid were to stay in the tissue?
It would cause swelling, known as oedema, so at the venule end, water in the fluid is returned to the blood through a process known as osmosis.
Why does osmosis happen?
Because the proteins that remain in the blood have a higher solute concentration, creating osmotic pressure, meaning that the water is drawn back through the capillary walls and into the blood.
What happens after the water has been drawn back into the blood?
Anything that is left of the tissue fluid (about 10%), drains into the lymph vessel.
What is the lymphatic system?
A drainage network of vessels that transports nutrients to the cells and collapse their waste products.
What happens to any tissue fluid that is not absorbed back into the lymphatic system?
It is absorbed into the lymphatic system.
What do the lymphatic tubes do and what is their structure?
They are very fine and carry a colourless liquid called lymph.
What does lymph contain?
A high number of white blood cells called lymphocytes.
What does the lymph flow through?
The lymph vessels into the lymph nodes, which filter out any bacteria or damaged cells.
What happens from the lymph nodes?
Lymph moves into larger lymphatic vessels at the base of the neck called the thoracic duct.
