Lecture 18

Question 1

continuous capillary

Answer 1

skin, CNS, muscle, lungs, CT. Endothelial cells are uninterrupted with continuous basal lamina therefore tight, not leaky. Large molecules and hydrophilic substrances transported via endo and exocytosis. Diffusion of gases and small molecules.

Question 2

Fenestrated capillaries

Answer 2

Endocrine glands, GIT. Important for fluid and metabolite absorption. 80nm hole in plasma membrane in endothelium but continuous basal lamina. Very small substances can move through.

Question 3

Discontinuous capillaries

Answer 3

AKA sinusoidal/sinusoids. Liver, bone marrow and spleen. Large, irregular luminal diameter. More in immune system. Gaps in endothelial cells and pores in plasma membrane. Partial/non basal lamina. Permeable to large molecules, leukocytes and erythrocytes.

Question 4

Endocardium

Answer 4

Tunica intima is in contact with blood. Endothelium, loose CT, Purkinje fibres (conducting system). Biggest giveaway that it is endocardium is Purkinje fibres

Question 5

Purkinje fibres

Answer 5

Modified cardiomyocytes with a neural function. Large, round nuclei, pale staining. Endocardium only.

Question 6

Epicardium

Answer 6

Visceral layer of serous pericardium. Adheres to outer surface of the heart. Mesothelium, adipose tissue and CT. Reflects back to form parietal serous pericardium