31/01/2023
The Blood vessels
→Substances transported in the blood need to reach the individual cells. Every cell in
your body within 0.05mm of a capillary - the tiniest blood vessel in the body.
→There are 3 main types of blood vessels:
Arteries
→Carry blood away from your heart to the
organs of the body. This is oxygenated
blood.
→They stretch as blood is forced through
and go back to shape afterwards.
→They have a pulse →where the arteries
run close to the skin's surface (e.g; at your
wrist).
→Have thick walls containing muscle and
elastic fibres.
→As the blood in the arteries is under
pressure, it is very dangerous if an artery
is cut, because the blood will spurt out
rapidly every time your heart beats.
Veins
→Carry blood away from your organs towards your
heart. This is deoxygenated blood.
→ Do not have a pulse.
→Have much thinner walls than arteries and often have
valves to prevent the backflow of blood.
↳Valves open as blood flows through them towards the
heart, but if the blood starts to flow backwards, they clove
and prevent a backflow of blood.
↳Blood is squeezed back towards the heart by the action
of skeletal muscles.
The Blood vessels
→Substances transported in the blood need to reach the individual cells. Every cell in
your body within 0.05mm of a capillary - the tiniest blood vessel in the body.
→There are 3 main types of blood vessels:
Arteries
→Carry blood away from your heart to the
organs of the body. This is oxygenated
blood.
→They stretch as blood is forced through
and go back to shape afterwards.
→They have a pulse →where the arteries
run close to the skin's surface (e.g; at your
wrist).
→Have thick walls containing muscle and
elastic fibres.
→As the blood in the arteries is under
pressure, it is very dangerous if an artery
is cut, because the blood will spurt out
rapidly every time your heart beats.
Veins
→Carry blood away from your organs towards your
heart. This is deoxygenated blood.
→ Do not have a pulse.
→Have much thinner walls than arteries and often have
valves to prevent the backflow of blood.
↳Valves open as blood flows through them towards the
heart, but if the blood starts to flow backwards, they clove
and prevent a backflow of blood.
↳Blood is squeezed back towards the heart by the action
of skeletal muscles.
