The Heart and Blood Vessels (arteries and veins) Flashcards
What blood vessels carries blood away from the heart?
Arteries
What are arterioles?
The smaller vessels which arteries are divided into
What is the name given to arteries which have been divided into smaller vessels?
Arterioles
What blood vessels carry blood to the heart?
Veins
What are venules?
Small veins
What are small veins called?
Venules
How many similar layers do both arteries and veins have in their walls?
They have three similar layers in their walls
What is the basic, main difference between an artery and a vein?
Veins have a thinner middle layer than arteries
Why do veins have a thinner middle layer than arteries?
As veins have a larger lumen
What are the three layers of both arteries and veins?
Inelastic protein
Muscle and elastic fibres
Endothelium
Describe the inelastic protein layer of both veins and arteries.
(4)
This is the outer layer
It is tough
It is made of inelastic protein called collagen
This layer prevents the walls from over-expansion
Describe the middle layer of both veins and arteries?
4
It is made of muscle and elastic fibres
The muscle is involuntary and can alter the size of the vessel
This allows arteries to expand during exercise which allows more blood to enter certain muscles and helps keep us cool as heat is lost
The elastic fibres bring the vessel back to shape when the muscle relaxes
Describe the inner layer of both arteries and veins?
2
It is a single layer of living cells called the endothelium
It surround the lumen
