capillaries, veins, venules

Question 1

Capillaries are

Answer 1

microscopic vessels that usually
connect arterioles and venules

Question 2

capillary walls are composed of

Answer 2

a single layer of cells
and a basement membrane

Question 3

capillary walls are so thin, and this permits the

Answer 3

exchange of nutrients and wastes between blood and
tissue cells

Question 4

Capillaries branch to form an extensive capillary
network throughout the tissues and are found

Answer 4

near almost every cell in the body

Question 5

small vessels that are formed by the union
of several capillaries

Answer 5

Venules

Question 6

Venules drain blood from

Answer 6

capillaries into veins

Question 7

How are veins formed?

Answer 7

Veins are formed from the
union of several venules

Question 8

How do veins differ from arteries and why?

Answer 8

veins have a thinner tunica
interna and tunica media
and a thicker tunica
externa.
- because veins have less elastic
tissue and less smooth
muscle than arteries

Question 9

Veins also contain

Answer 9

valves

Question 10

The tunica externa is often thicker in veins to prevent _____ and protection from

Answer 10

collapse of the blood vessel and provide protection from
damage since veins may be superficially located