Blood vessels and types

Question 1

State structure and functions of the Arteries

Answer 1

Structure:
Thick wall
Smooth muscle
elastic fibres
Lined with smooth layer of endothelial cells

Function:
Withstand high blood pressure
Alter diameter of lumen to vary blood flow
Allow walls to stretch when blood is pumped into the artery and then recoil, smoothing blood flow
Low friction surface to ease blood flow

Question 2

State the structure and function of the Capillaries

Answer 2

Structure:
Very thin wall, one cell thick
Small lumen

Function:
Allow rapid exchange between blood and tissues
Link arteries and veins

Question 3

State the structure and function of veins

Answer 3

Structure:
Relatively thin wall
Very little smooth muscle or elastic fibres
Wide lumen
Valves

Function:
Blood under low pressure
No pulse of blood so no stretching and recoiling
Large volume acts as blood reservoir
Valves stop backflow, ensuring a one-way flow of blood toward the heart