B2.2.2 - Circulatory System Flashcards
1
Q
What does the circulatory system do?
A
Carries oxygen + nutrients to cells and removes waste
2
Q
Explain the double circulatory system
A
There are two systems in the heart. On the left, oxygenated blood is sent to the whole body. On the right, deoxygenated blood is sent to the lungs only. This is why the left side has thicker muscle
3
Q
What do arteries do?
A
Carry (oxygenated) blood AWAY from heart
4
Q
What do veins do?
A
Carry (deoxygenated) blood TOWARDS the heart
5
Q
What do capillaries do?
A
Allows blood flow close to cells, enabling substances to move between them
6
Q
Describe the structure of an artery (4)
A
- small lumen
- thick layers of muscle/elastic fibres
- muscle in walls make it strong
- elastic fibres allow stretching, withstand high pressure
7
Q
Describe the structure of a vein (4)
A
- large lumen (allows low pressure blood)
- thin layer of muscle/elastic fibres
- valves to prevent back flow
8
Q
Describe the structure of an capillary
A
- very small lumen
- single cell thick wall -> creates short diffusion pathway
- permeable walls allowing substance movement
