Things I should know from other lectures

Question 1

What are the 3 layers of blood vessels? Describe their composition?

Answer 1

Tunica intima – Composed of endothelium and collagen
Tunica media – Composed of mainly smooth muscle (also have elastic fibres, giving a degree of flexibility)
Tunica adventitia – Composed of mainly connective tissue (also have nerves, fibroblasts etc.)

Question 2

Definitive features of elastic arteries?

Answer 2

Have very thick T. media with many elastic laminae which are well organised (sheets of elastin aka lamellae). This organization allow them to absorb systolic flow by stretching and continue blood flow in diastole by elastic recoil.

Question 3

What happens when you stain muscular arteries with EVG?

Answer 3

We see an internal elastic lamina separating the intima from media.

Question 4

Where are the elastic laminae located in the elastic and muscular arteries?

Answer 4

Elastic arteries have many elastic laminae in the T. media. Muscular arteries have a single internal and external elastic lamina, internal and external (at edges) to T. media (not in).

Question 5

Why is the T. media predominant in arterioles?

Answer 5

Arterioles are important in regulating blood pressure and flow, globally and locally. The T. media is predominant for contractility against high BP, the smooth muscle runs circularly.

Question 6

What is the composition of capillaries?

Answer 6

Composed of an endothelium only, with scattered pericytes (spindly cells suggested to be stem cells for repair).

Question 7

Name the different types of capillary?

Answer 7

Continuous capillaries have no holes in their walls.
Fenestrated capillaries have many tiny pores in the wall (going right through the cytoplasm). This makes them more permeable.
Sinusoids are wider fenestrated capillaries (pores are larger).

Question 8

What are the 3 layers of the heart?

Answer 8

Epicardium = Outer layer, composed of fatty loose connective tissue with nerves, blood vessels including coronary arteries. Also has a smooth lubricated epithelial covering on top called the mesothelium.
Myocardium = Beneath epicardium, contracts to give the heart beat.
Endocardium = Thin layer of endothelium and some loose connective tissue.