Animal Transport
Circulatory System
The circulatory system is a system of blood vessels and valves.
- Valves prevent the backflow of blood
- Most mammals have a double circulatory system
Double Circulation
Circulation occurs to both the lungs and to the body tissues in mammals. This gives the heart more control over blood pressure.
- Blood is pumped at a lower pressure to the lungs to not damange the delicate lung tissues
- Blood is pumped at a higer pressure to the rest of the body to supply organs with oxygen more quickly and frequently
Blood Components
Blood is made up of 3 main components:
- red blood cells
- white blood cells
- platelets
These components are carried by plasma which also contains nutrients and waste products such as:
- glucose
- amino acids
- carbon dioxide
- urea
Red Blood Cell
A red blood cell is a specialised cell that contains haemoglobin in its cytoplasm. Haemoglobin binds to oxygen during gas exchange. This helps red blood cells transport oxygen and deliver it to organs for respiration.
White Blood Cell
A white blood cell is a type of cell that is part of the immune system. White blood cells play a major role in:
- Phagocytosis: the process of ingesting and killing foreign microorganisms
- Antibody Production: the process of releasing antibodies to slow the movement of pathogenic cells