12. Skin And Breast

Question 1

5 layers of epidermis

Answer 1

Stratum corneum= dead keratinising squamous
Stratum lucidem
Stratum granulosum = flattened squames produce keratin
Stratum spinosum = polygonal keratinocytes, sensory Merkel cells and antigen recognising Langerhan cells
Stratum basale = single stem layer

Question 2

Melanocyte function

Answer 2

MSH and ACTH stimulates melanocyte formation from tyrosine and transport to keratinocytes.

Question 3

What are epidermal adnexae?

Answer 3

Downgrowths of epidermis into dermis
(Dermal papillae = boundary)
Sebaceous glands produce sebaceous secretion to lubricate + waterproof fair
Eccrine = most common gland
Apocrine

Question 4

Nails

Answer 4

Compacted keratin from nail matrix cells firmly attached except at distal

Question 5

Hair

Answer 5

Hair arise from germinative epithelium within bulb and contains melanocytes for hair colour
Epidermis root sheath surrounded by collagenous follicle sheath. Erector pills muscle causes hair to stand

Question 6

2 layer of dermis

Answer 6

Papillary dermis = few collagen fibres
Reticular dermis = rich collagen fibres

Question 7

Subcutis structure

Answer 7

White adipose connective tissue and fibrovascular septa = provides insulation, food store and shock absorber

Question 8

Meissner’s corpuscle bs Pacinian Corpuscle

Answer 8

M - Encapsulated unmyelinated nerve endings under dermal papillae, surrounded by Schwann cells = fine touch
P - Encapsulated sensory receptors in deep dermis. Membrane lamellar separated by fluid = vibration + pressure

Question 9

Eyelid

Answer 9

Inner moist conjunctival surface of stratified columnar
Large Meibomian gland = modified sebaceous secretes lipid rich to reduce evaporation

Question 10

Breast

Answer 10

Myoepithelial system of ducts and lobules around terminal duct in fibroadipose connective tissue.

Outer myoepithelial, inner columnar

Question 11

Lactating breasts

Answer 11

Inner layer of secretory cells become vacoulated