Pathology and Disease

Question 1

Hyperkeratosis

Answer 1

Increased thickness of the keratin layer

Question 2

Parakeratosis

Answer 2

Persistence of the nuclei in the keratin layer

Question 3

Acanthosis

Answer 3

Increased thickness of the epithelium

Question 4

Papillomatosis

Answer 4

Irregular epithelial thickening

Question 5

Spongiosis

Answer 5

Intercellular oedema in the epidermis, manifested clinically as intraepidermal vesicles

Question 6

Histology of Lichenoid Disorders

Answer 6

Irregular sawtooth acanthosis as well as hypergranulosis and orthohyperkeratosis

Question 7

Acantholysis

Answer 7

Loss of desmosomes

Question 8

Mechanism of Aciclovir

Answer 8

Guanosine analogue

Incorporated into viral DNA, prevents replication

Question 9

Tuberous Sclerosis

- Cutaneous Features

Answer 9

1. Ash leaf spots
2. Shagreen patches - roughened patches over lumbar spine
3. Angiofibroma
4. Subungal fibromata

Question 10

Tuberous Sclerosis

- Genes

Answer 10

TSC1 and TSC2
= code for tuberin and hamartin
= tumour regulating genes

Question 11

Tuberous Sclerosis

- Neurological Features

Answer 11

Epilepsy
Intellectual impairment
Developmental delay

Question 12

Epidermolysis Bullosa

- Classification

Answer 12

Simplex - blistering on rubbing, failure of keratinisation
Junctional - affects lamina and collagen
Dystrophic - affects skin and other organs
Problems with Type VII collagen

Question 13

Type II Neurofibromatosis

• Mutation
• Features

Answer 13

On chromosome 22

1. Bilateral acoustic neuromas
2. Multiple intracranial schwannomas
3. Meningiomas

Question 14

Type I Neurofibromatosis

• Signs
• Mutation

Answer 14

1. Cafe au lait spots
2. Axillary freckling
3. Neurofibromas
   On chromosome 17 < neuofibromin

Question 15

Layers of the Epidermis

Answer 15

Keratin layer (stratum corneum)
Granular layer
Prickle cell layer
Basal layer

Question 16

Keratin Layer

• Function
• Contents

Answer 16

= form a tight waterproof barrier

• Made up of keratin and filaggrin as well as cell remnants
• Keratinocytes here should NOT have nuclei

Question 17

Granular Layer

• Function
• Contents

Answer 17

= thin layer of two-three layers of flatter cells

- Contains granules, filaggrin and proteins: high lipid content

Question 18

Prickle Cell Layer

• Function
• Contents

Answer 18

= allows dynamic movement and communication

- Lots of intermediate filaments, lots of desmosomes

Question 19

Keratinocytes

Answer 19

Migrate up from basement membrane

Question 20

Langerhan’s Cells

- Found

Answer 20

APC picks up antigen and circulates
Found: prickle cell level, dermis
- Present antigens to T cells

Question 21

Merkel Cells

• Found
• Function

Answer 21

Found: between keratinocytes and nerve fibres
Function: work to detect touch = mechanoreceptors

Question 22

Melanocyte

• Found
• Function

Answer 22

Found: basal layer and above
Function: in their melanosomes convert tyrosine to melanin

Question 23

Function of melanin

Answer 23

Protects DNA production from UV radiation

Question 24

Where to melanocytes come from?

Answer 24

Neural crest

Question 25

Th2 cells implicated in…

Answer 25

Atopic dermatitis

Question 26

Th17 cells implicated in…

Answer 26

Atopic dermatitis

Psoriasis

Question 27

Mast Cells

• Activation
• Pre-formed mediators

Answer 27

Activation = IgE binding

Pre-formed: chymase, tryptase, TNF and histamine

Question 28

Eccrine Gland

• Found especially
• Function

Answer 28

Found: palms, soles
Function: cooling by evaporation, moisten soles/palms to aid grip

Question 29

Apocrine Gland

• Found especially
• Depend on
• Function

Answer 29

Found: axillae, perineum
Depend: androgens
Function: produce oily fluid

Question 30

Sebaceous Gland

• Found especially
• Depend on
• Function

Answer 30

Found: chest, face
Depend: hormone sensitive
Function: produce squalene, wax