L46 Epithelial Defects and Disease

Question 1

What is metaplasia?

Answer 1

When a cell differentiates into a new cell type in response to environmental stimuli.

Most common in epithelial tissue.

Question 2

Why do many tissues become squamous epithelium when they undergo metaplasia?

Answer 2

It is the most protective tissue type.

But, this means the tissue loses its function.

Question 3

Is an adenoma benign or malignant?

Answer 3

Benign

The malignant form would be adenocarcinoma.

Question 4

True or false: Dysplasia is irreversible

Answer 4

False.

Dysplasia is reversible

Question 5

True or false: metaplasia is reversible

Answer 5

True

Question 6

True or false: anaplasia is irreversible and produces a tumour.

Answer 6

True

Question 7

What disease causes thickening and inelasticity of artery walls?

Answer 7

Atherosclerosis

Accounts for 50% of deaths in Western World

Question 8

What are the risk factors associated with atherosclerosis?

Answer 8

Age, sex (male), hyperlipidaemia, hypertension, diabetes mellitus, smoking

Question 9

What causes atherosclerosis?

Answer 9

Endothelium is damaged and LDL’s enter tunica intima (fatty streak) forming an atheroma.

As the atheroma grows and accumulates fatty material, platelet aggregation and thrombosis occur in the endothelium.

Cumulative effect is narrowing of vessels, ultimately leading to infarction.

Question 10

What is the pathophysiology associated with non-specific dermatitis (eczema)?

Answer 10

Red, itchy, tender skin.

Tiny blisters - vesicles form in epidermis due to fluid accumulation.

Vesicles erupt, releasing clear, yellow fluid that crusts over.

Question 11

What causes thickening of epidermis in chronic dermatitis?

Answer 11

Repeated trauma leads to:

• Increased cell population in epidermis
• Surface hyperkeratosis
• Elongation of rete ridges