Blood Vessels

Question 1

What are arteries?

Answer 1

Conducting vessels

carry blood away from the heart

Question 2

What are arterioles?

Answer 2

resistance vessels
mini arteries that branch out into the capillaries
smooth muscle–> for redistributing blood
decrease blood pressure going into the capillaries
Smooth muscle controls the lumen
have pre capillary sphincters which provide a gateway

Question 3

What are veins?

Answer 3

capacitance vessels

carry blood towards the heart

Question 4

What are venules?

Answer 4

capacitance vessels

smallest vein components that suck blood out of the capillaries

Question 5

What is the tunica intima?

Answer 5

inner layer of the blood vessel
endothelial lining and surrounding layer of connective tissue with a variable number of elastic fibres
arteries contain a thick layer of elastic fibres called the internal elastic membrane

Question 6

What is the tunica media?

Answer 6

middle layer of the blood vessel
contains concentric sheets of smooth muscle tissue in a framework of loose connective tissue
the collagen fibres bind the tunica media with the tunica intima and externica
separated from the externica by a thin band of elastic fibres called the external elastic membrane
smooth muscle cells encircle the endothelium
vessel decreases in diameter when the smooth muscle contracts

Question 7

What is the tunica external?

Answer 7

outer layer of the blood vessel
in arteries it contains collagen fibres with bands of elastic fibres
in veins it is is thicker than tunica media and contains networks of elastic fibres and bundles of smooth muscle cells
connective tissue fibres blend into the adjacent tissues which stabilises the blood vessel