CH8 blood vessels Flashcards
1
Q
What are three of the components of blood vessels
A
- elastic fibres
- smooth muscle
- collagen
2
Q
Function of elastic fibres
A
- composed of elastin
- can stretch and recoil
- provides vessel walls with flexibility
3
Q
Function of smooth muscle
A
- contracts or relaxes which changes size of lumen
4
Q
Function of collagen
A
- provides structural support
- maintains shape and volume of vessel
5
Q
Purpose of arteries
A
- carry blood away from heart to body tissues
- carry oxygenated blood except for pulmonary artery and umbilical artery
6
Q
Structure of arteries
A
- walls contain elastic fibres, smooth muscle and collagen
- elastic fibres allow them to withstand force of blood pumped out of heart and stretch
- in between contractions, fibres recoil and return to their original length which helps to even out surges of blood pumped from heart to give a continuous flow
7
Q
Structure and function of arterioles
A
- link arteries and capillaries
- more smooth muscle and less elastin
- can constrict and dilate to control blood flow
8
Q
Function of capillaries
A
- link arterioles and venules
- substances are exchanged through capillary walls
9
Q
Adaptions of capillaries
A
- large surface area
- one cell thick
- larger cross section than arterioles supplying them which slows down flow
10
Q
Function of veins
A
- carry blood towards the heart
- mostly deoxygenated except for pulmonary vein and umbilical vein
11
Q
Structure of veins
A
- valves
- walls contain lots of collagen and little elastic fibre
12
Q
Structure and function of venules
A
- link capillaries with veins
- thin walls with little smooth muscle
13
Q
How are veins adapted to move against gravity
A
- one-way valves to prevent backflow
- bigger veins run between active muscles and when they contract, veins are squeezed which forces blood in veins towards the heart
- breathing movements of chest act as a pump
