Blood vessels




tissue fluid

HideShow resource information


Tunica externa

Contains elastic fibres and collagen fibres to provide strength and durability.

Tunica Media

-Contains smooth muscle that contract and constrict the artery which makes the lumen narrower.

-Contains elastic fibres which allow the artery to expand and recoil as there is a high pressure of blood there are very thick walls.

Tunica intima

collagen fibres, smooth muscle, inner endothelium (flat cells of squamous epithelium and elastic tissue which allows expansion and recoil without bursting or rupture.

Lumen - gap is small to keep the high pressure of blood

1 of 5

Diagram of the artery compared to vein


2 of 5


Pressure is low as veins carry blood back to the heart

Valves to prevent back flow and prevent blood flowing in the opposite direction. Large lumen to intake lots of blood

Tunica intima


Tunica media

Thinner layers of smooth muscle and elastic fibres as they dont need to stretch and recoil and are not actively consticted to reduce blood flow

Tunica externa

mostly collagen fibres

3 of 5

Veins compared to the artery


4 of 5


5 of 5


Sane Insanity


It is tunica externa and exterta. Not tunic



whoops thanks 

Similar Biology resources:

See all Biology resources »See all Biological molecules, organic chemistry and biochemistry resources »