4.2 The blood vessels Flashcards
1
Q
What are arteries
A
Carry oxygenated blood away from your heart to the organs of your body
2
Q
Adaptations of arteries
A
- Stretch as blood enters, back to shape after (Pulse)
- Thick walls containing elastic and muscle fibres
- small lumen to withstand pressure
3
Q
What are veins
A
Carry deoxygenated blood from body to heart
4
Q
Adaptations of veins
A
- Large lumen to assit blood flow
- Thin elastic walls
- Valves to prevent backflow
5
Q
What are capillaries
A
Tiny vessels linking arteries and veins, they carry nutrients/gases to tissues and remove waste products
6
Q
Adaptations of capillaries
A
- Walls a cell thick to allow nutrients and gases to diffuse through
- Tiny vessel with narrow lumen
7
Q
Features of pulmonary circulation
A
- Low blood pressure
- Thin walls with little smooth muscle
- Similar pressure
8
Q
Features of Systemic circulation
A
- High blood pressure
- Pressure varies according to distance from heart
- Thicker walls with abundant smooth muscles
9
Q
Do veins have a pulse?
A
No
10
Q
How is blood from the veins squeezed back toward the heart?
A
By the action of the skeletal muscles
11
Q
Why is a double circulatory system important in warm blooded, active animals
A
it makes the circulatory system very efficient, more areas of the blood can receive fully oxygenated blood more quickly
