the circulatory system Flashcards
1
Q
features of arteries
A
narrow tube to keep high pressure of blood flow
thick elastic layer of muscle fibres
2
Q
features of vein
A
Valves to prevent back flow
thin flexible wall
low pressure
wide tube
3
Q
Plasma
A
straw coloured fluid carrying glucose, CO2 and urea
4
Q
Red blood cells
A
packed with haemoglobin which binds with oxygen in lungs and releases it in tissues
5
Q
Why are red blood cells shaped like biconcaves
A
to increase the surface area for diffusion
