3.2 Transport In Animals (blood Vessels) Flashcards
What are the three types of blood vessels?
Artery
Vein
Capillary
Why do Arteries have a narrow lumen?
Maintains a high blood pressure
Why do arteries and veins have collagen?
Strengthens walls to withstand high blood pressure
What is the purpose of an artery?
To transport oxygenated blood away from the heart
What are the purpose of veins?
Transport deoxygenated blood back to the heart
Why do arteries have elastic fibres?
Allows walls to stretch and recoil
What is the purpose of a folded endothelial layer in blood vessels?
Can expand when they stretch
Smooth layer reduces frictiom
What is vascular shunting?
Allows the body to prioritise where blood should flow
What are the purpose of capillaries?
They link arteries and veins
Only place where exchange takes place
What are the features of a capillary that makes them good for exchange?
Single layer of endothelial cells=very thin walls- Reduces diffusion distance for exchange of substances
Lots of them = Large surface area
Which blood vessels contain valves?
Veins. Arteries and Capillaries do not
