Btec applied science unit 5 biology revision booklet

Structure Function

Arteries Thick muscular tube lined by smooth tissue, to control the Carry blood away from the heart, at high pressure.
volume of blood, and prevents the vessels bursting under the
Delivers oxygenated blood to the body from the heart.
high pressure.

Made up of small lumen, so blood is under high pressure.

In addition to endothelium, elastic fibres, smooth muscles, and
collagen muscles.

Veins Veins Carry blood to the heart at low pressure.
Large in diameter. Carry deoxygenated blood from the body to the heart.

Have thinner walls in proportion to their lumen.

Little elastic tissue in the wall - low pressure will not cause them
to burst

Capillaries Walls made up of: Links arterioles to ventricles

Inner layer of one cell thick endothelial cells for rapid diffusion Responsible for facilitating the transport and exchange of
gases, fluids, and nutrients in the body.
Outer layer of epithelial cells.

Have very small lumen to reduce the diffusion distance

Have numerous highly branched providing big surface area for
diffusion.