Histology IV - Cardiovascular system

Question 1

Describe the structure of the heart

Answer 1

Surrounded by pericardium, fibrous (outer) and serous (inner). Pericardial cavity between parietal pericardium and epicardium coated by visceral pericardium. Myocardium then endocardium.

Question 2

Endocardium structure

Answer 2

Inner epithelial layer
Middle dense connective tissue/smooth muscle
Subendocardial: connective tissue, conducting tissue.

Question 3

The heart’s conductive structure

Answer 3

Sinoatrial (SA) node -> Atrioventricular (AV) node -> Bundle of His -> Purkinje fibers

Question 4

Histological characteristics of conducting cells

Answer 4

PAS-positive (bundles).

pacemaker-cells. nodes.

Question 5

Layers of arteries and veins

Answer 5

intima>media>adventitia
Intima: endothelial, basallamina, loose connective tissue.
Media: smooth muscle + elastin and reticular fibers. to external elastic embrane.
Adventitia: Vasa vasorum, vascularisation to the artery itself. Nervi vascularis. Connective tissue?

Question 6

What capillaries?

Answer 6

Continuous
Fenestrated
Sinusoid

All have basalmembrane

Question 7

Histological difference between vein and artery

Answer 7

Tunics less well-defined in veins.
Thinner walls
Media thin
Poorly defined internal elastic membrane
Collapsed.