Section 2

Question 1

What are the three tunics of blood vessels?

Answer 1

1. Tunic externa
2. Tunic media
3. Tunic intima

Question 2

What is the tunic externa of the blood vessel?

Answer 2

• Outside layer
• Tunic sterna or adventitia
• Composed of connective tissue with collagen and elastic fibres

Question 3

What is the tunic media of the blood vessel?

Answer 3

• Middle layer
• Composed of smooth muscle and elastic fibers

Question 4

What is the tunic intima of the blood vessel?

Answer 4

• Inner lining
• Composed of simple squamous epithelium, AKA endothelium

Question 5

What are the two different types of blood vessels in the cardiovascular system?

Answer 5

Arteries and veins

Question 6

Where are elastic arteries located, and what are their characteristics?

Answer 6

• they are large arteries near the heart (e.g aorta)

Characteristics:
- large lumen
- tunica media has more elastic fibres than smooth muscle
- exhibit stretching and recoil characteristics

Question 7

Where are muscular arteries located, and what are their characteristics?

Answer 7

• they deliver blood to the various regions and organs of the body

Characteristics:
- thick tunica media with a lot of smooth muscle
- exhibit contractile characteristics

Question 8

What are arterioles, and what are their characteristics?

Answer 8

• muscular arteries typically lead to large arterioles, which then lead to smaller arterioles.
• larger arterioles have three tunics, but the tunica media only consists of a few layers of smooth muscle
• smaller arterioles have a single layer of smooth muscle around the tunica intima

Question 9

What are capillaries, and what are their characteristics?

Answer 9

• they are the smallest blood vessels
• they are the transition between arterioles (arterial system) and venules (venous system)

Characteristics:
- diameters ranging from 8-10 micrometers
- consist of only the tunica intima (layer of endothelial cells plus a thin basement membrane)

Question 10

What are venules, and what are their characteristics?

Answer 10

• the smallest venules resemble capillaries in structure, and they consist of only one tunic
• smaller venules give rise to larger venules that have three tunics, but each tunic is extremely thin
• venules have much larger lumen and diameter compared to capillaries and arterioles

Question 11

What are veins, and characteristics?

Answer 11

• venules give rise to small veins, and ultimately large veins

Characteristics:
- larger lumen compared to arteries
- far less muscle in the tunica media compared to arteries
- veins have one-way valves that prevent blood from flowing backwards

Question 12

Which is the correct blood vessel?
“Tunica media has more elastic fibres and as a result exhibits stretching and recoil characteristics.”

Answer 12

Elastic artery

Question 13

Which is the correct blood vessel?
“Consists of only a tunica intima and basement membrane.”

Answer 13

Capillary

Question 14

Which is the correct blood vessel?
“Three tunics, large lumen, and valves to prevent backflow of blood.”

Answer 14

Vein

Question 15

Which is the correct blood vessel?
“Tunica media has lots of smooth muscle and the vessel exhibits contractile characteristics.”

Answer 15

Muscular artery

Question 16

Which is the correct blood vessel?
“Three tunics but very thin.”

Answer 16

Venule

Question 17

Which is the correct blood vessel?
“Few to one layer of smooth muscle around an endothelium.”

Answer 17

Arteriole