LC Biology- Lymphatic system

What is the lymphatic system?

A secondary transport system that returns tissue fluid form around the cells to the blood.

What is tissue fluid?

Plasma that has been forced out of capillaries due to high pressure, there is no red blood cells or platelets in it, also called extra cellular fluid

How is tissue fluid removed?

90% of tissue fluid returns naturally to the capillaries via osmosis

10% enters lymph vessels (lymph) contains white blood cells, proteins and fats.

Lymph vessels

Ensures lymph travels one way by use of valves.

Lymph vessels eventually combine to form thoracic duct and lymphatic duct.

These ducts empty lymph back into blood via subclavian veins

Lymph nodes

Swellings along lymph vessels

Filter bacteria

Store lymphocytes

3 functions of lymphatic system

1) to return tissue fluid to blood

2) to defend the body against infection

3) to transport fat

through what structures does lymph return to the blood stream?

subclavian vein

Explain why lymph nodes may sometimes be swollen

Due to fighting infection

Give 2 ways lymph differs from blood

lymph contains white blood cells and a higher level of fats