circulatory system

Question 1

Main components

Answer 1

• blood
• heart
• arteries
• veins
• capilleries

Question 2

Functions of system and blood

Answer 2

Deliver oxygen and nutrients to cells and remove waste, via blood :
- transporting oxygen and nutrients to the lungs and tissue
- forming blood clots to prevent excess blood loss
- carrying cells and antibodies that fight infections
- bringing waste products to kidney and liver which then filter it

Structure of blood
- liquid: plasma (water, salts and protein)
- solid: red blood cells, white blood cells, platelets (form clots)

Question 3

Blood vessels

Answer 3

1. Arteries
   - distribute oxygen-rich blood to the entire body
2. Capillaries
   - where oxygen and nutrients are exchanged for carbon dioxide and waste
3. Veins
   - return oxygenated blood back to the heart

Question 4

Pathway of blood through the body

Answer 4

1. Right atrium accepts deoxygenated blood.
2. Deoxygenated blood passes through tricuspid valve in right ventricle.
3. Right ventricle contracts to push the blood through pulmonary valve into pulmonary artery.
4. Pulmonary artery transports deoxygenated blood to the lungs.
5. Gas exchange occurs.
6. Oxygenated blood returns to the left atrium through the pulmonary vein.
7. It drops down to left ventricle through mitral valve.
8. Left ventricles pushes blood through aortic valve into aorta.
9. Aorta transports oxygenated blood to all cells in the body via a network of blood vessels.
10. Deoxygenated blood returns to right atrium through superior and inferior vena cava.
    - Cycle starts again