Blood, Tissue fluid & lymph
Blood:
- Transport medium in the human circulatory system.
- 55% of the blood is plasma: a yellow liquid which contains...
- Glucose
- Amino Acids
- Mineral Ions
- Hormones
- Albumin (for maintaining oncotic pressure)
- Fibrinogen (for blood clotting)
- Globulins (for transport and immunity)
- The other 45% is:
- Erythrocytes (red blood cells)
- Platelets (cell fragments for blood clotting)
- Leucocytes (white blood cells)
- Functions of the blood include:
- Transport of oxygen and carbon dioxide, digested food, nitrogenous waste, hormones, platelets, cells and antibodies in the immune response.
- Maintains body temperature.
- Acts as a pH buffer.
Tissue Fluid:
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Key Terms: |
Lymph:
- 5-10% of tissue fluid drains into blind ended lymphatic capillaries.
- Lymph contains less oxygen and nutrients than tissue fluid, but more fatty acids which are absorbed from the small intestine.
- Like in veins, lymph is moved along lymph vessels by contraction of surrounding muscle. Lymph vessels, like veins, have one way valves to stop back-flow.
- Lymphocytes build up at lymph nodes along the lymph vessels, and produces antibodies.
- Lymph eventually re-enters blood.