blood vessels Flashcards
1
Q
what is the function of the arteries?
A
carries blood away from the heart to the rest of the body
2
Q
describe the blood in the arteries
A
- oxygenated blood
- high pressure
3
Q
what are the adaptations of the arteries?
A
- lots of smooth muscle and elastin to withstand forces of blood flow and stretch to take large volumes
- between contractions they recoil to maintain continuous flow
- smooth endothelium for easy blood flow
- small lumen due to high pressure allows blood to be transported with great force over a long distance
4
Q
describe the arterioles
A
- more smooth muscle, less elastin
- constrict and dilate to control blood flow
5
Q
what is the function of the veins?
A
carries blood towards the heart
6
Q
describe the blood in the veins
A
- deoxygenated
- low pressure
7
Q
what are the adaptations of the veins?
A
- wide lumen, lots of collagen = large reservoir of blood
- valves = prevent backflow
8
Q
describe the venules
A
- thin walls
- less smooth muscle
9
Q
what are the capillaries?
A
an extensive network of microscopic vessels
10
Q
describe the adaptations of the capillaries
A
- small 1 cell thick lumen = increases diffusion rate
- large SA = diffusion
- large cross section = slow movement and more time for material exchange
11
Q
describe the process of blood passing through the capillaries
A
- oxygenated blood enters via arterioles
- oxygen level of the blood decreases
- deoxygenated blood enters venules
