Artery and vein

Question 1

What is the vasa vasorum?

Answer 1

Small networks of blood vessels that deliver nutrients, oxygen and blood and remove waste. They’re found around larger blood vessels.

Question 2

What are the main layers of the artery/vein?

Answer 2

1. Tunica adventitia: longitudinal collagen fibres and vasa vasorum.
2. External Elastic Lamina
3. Tunica Media: 2-3 layers of smooth muscle cells (Media = Muscle)
4. Internal Elastic Lamina
5. Tunica Intima: Thin endothelial lining

Question 3

Where are the erythrocytes found?

Answer 3

The lumen of the artery/vein

Question 4

What are the differences between artery and vein in terms of structure?

Answer 4

• The external and internal elastic layers are not always present, if not tiny in veins as they don’t carry blood at high pressure.
• The lumen of the vein is flattened and collapsed (not circular).
• There are far fewer smooth muscle cells in the tunica media of veins, as it doesn’t need to contract as much as arteries. Thus, the tunica media is smaller in veins.
• The tunica externa/adventitia is larger in veins than arteries.

Question 5

What are the broadest layers in veins and arteries respectively?

Answer 5

• Veins = Tunica adventitia
• Arteries = Tunica media

Question 6

Scattered __?__ characterise the adventitia in arteries.

Answer 6

Elastic fibres

Question 7

What type of connective tissue is contained in the tunica externa?

Answer 7

Dense irregular

Question 8

What type of cells surrounds the lumen?

Answer 8

Flattened endothelial cells + simple squamous cells with a subendothelial later underneath.

Question 9

What cells are found in the tunica intima of arteries that increase in relation to ageing and atherosclerosis?

Answer 9

• Myointimal cells (that accumulate lipid with ageing, and the intima layer thickens increasing risk of atherosclerosis )
• The intima also has fibroblasts