Blood Vessels And Their Function Flashcards
What are the four types of blood vessel?
Arteries
Artérioles
Capillaries
Veins
What do arteries carry?
Blood away from the heart and into artérioles.
What are artérioles?
These are smaller arteries that control blood flow from arteries to capillaries.
What are capillaries?
These are tiny vessels that link artérioles to veins.
What do veins do?
They carry blood from capillaries back to the heart.
What is the structure of blood vessels?
From the outside in: Tough fibrous outer layer Muscle layer Elastic layer Thin inner lining. (Endothelium) Lumen
What differs between each type of blood vessel?
The proportions of each layer.
What does the tough fibrous outer layer resist?
Pressure changes from both within and outside.
What can the muscle layer do?
It can contract which allows it to control the flow of blood.
What does the elastic layer help to maintain?
It helps to maintain blood pressure by stretching and springing back (recoiling).
Why is the inner lining (endothelium) smooth?
To reduce friction.
Why is the endothelium thin?
To allow diffusion.
What is the lumen?
The central cavity of the blood vessel through which blood flows.
What is the difference between artérioles and arteries?
Artérioles are smaller in diameter and have a relatively larger muscle layer and lumen.
What has the biggest lumen?
Veins
What layers do capillaries have?
Lumen and lining layer.
Is the elastic tissue a muscle?
No
Which is bigger the lining of the artery or the vein?
The vein.
What is the function of a n artery?
To transport blood rapidly under high pressure from the heart to the tissues.
In what four ways are arteries adapted to their function?
They have a thick muscle layer compared to veins.
The elastic layer is relatively thick compared to veins.
The overall thickness of the wall is great.
There are no valves.
How does the thick muscle layer aid the function of arteries?
This means that smaller arteries can be constricted and dilated in order to control the amount of blood passing through them.
Why is it important that the elastic layer of arteries is thick?
This is because the blood pressure is high.
When is the elastic layer stretched?
During systole.
When does the elastic layer spring back?
During diastole