Veins Flashcards
1
Q
What direction do veins carry blood?
A
Towards heart
2
Q
What are 3 features of veins?
A
Wider lumen than arteries
Thinner layers of muscle & elastic tissue
Valves
3
Q
Why do veins have a wider lumen than arteries?
A
Blood is at low pressure
4
Q
What do valves do?
A
Ensure that blood does not flow backwards
5
Q
What do skeletal muscles do when they contract?
A
Compress veins, helping increase pressure & push blood along
6
Q
What do closed circulatory systems increase?
A
Pressure & speed of blood flow
