Skin and Breast

Question 1

Describe epidermis

Answer 1

Rests on basement membrane

Made of type IV collagen

Question 2

Describe stratum basale

Answer 2

Sits on basement membrane

Basal epithelial cells - stem cells

Melanocytes

Question 3

Describe melanocytes

Answer 3

Synthesise melanin and transfer it to surrounding keratinocytes in melanosomes in response to MSH and ACTH stimulation

Question 4

What is the role of melanin

Answer 4

Absorbs UV light protecting us from non-ionising radiation damage

Question 5

What can contain melanin

Answer 5

Epithelial

Melanocytes

Question 6

What is skin colour dependent upon

Answer 6

Melanocytes same in individuals

Depends on the amount and type of melanin

Question 7

What is usually the largest layer of the epidermis

Answer 7

Stratum spinosum

Question 8

Describe the stratum spinosum

Answer 8

Also called the prickle layer

Plump polygonal keratinocytes

Closely bound by desmosomes - Prominent intercellular adhesions (prickles between the cells)

Langerhans cells - antigen recognition

Merkel cells - sensory

Question 9

What is the role of langerhans cells

Answer 9

Antigen recognition

Question 10

What is the role of Merkel cells

Answer 10

Sensory

Question 11

Describe the stratum granulosum

Answer 11

Flattened squames

Eosinophilic cytoplasm

Haematoxophilic kerato-hyaline granules

Keratin forms in this layer

Question 12

Describe the stratum corneum

Answer 12

Acellular (cells are dead)

Plates of keratin

Prominent at certain sites - palms and soles

Question 13

What are epidermal adnexae

Answer 13

Downgrowths of the epidermis into the dermis

• hair follicles
• sebaceous glands
• eccrine sweat glands
• apocrine sweat glands

Question 14

Describe sebaceous glands

Answer 14

Accompany hair follicles

Produce sebaceous secretions which lubricate and waterproof hairs

Holocrine secretion - discharge entire cell

Question 15

Where are apocrine glands found

Answer 15

Armpits

Groins

Genitals

Anus

Produce ear wax

Question 16

Describe apocrine cells

Answer 16

Accompany hair follicles

Axillae and groins

Ceruminous glands in the ear

Simple coiled tubular glands

Eosinophilic cytoplasm

Apocrine secretions - cytoplasm of cells bud off from luminal surface

Function not entirely certain

Question 17

Describe eccrine glands

Answer 17

Thin watery secretions

Everywhere

Coiled tubes, 2 cell layers thick - inner secretory, outer myoepithelial

Eccrine (merocrine) secretion - exocytosis

Question 18

Describe the dermo-epidermal junction

Answer 18

Not flat

Epidermis protrudes downwards into the underlying dermis - rete pegs/ridges

Space between these is the papillary dermis

Question 19

Describe the dermis

Answer 19

Fibrous connective tissue containing elastin, blood vessels, nerves

Deepest layers see presence of fatty connective tissue

Irregular loose connective tissue

Question 20

What is the role of the meissners corpuscles

Answer 20

Fingers, palms and soles

Fine touch

Question 21

What is the role of the pacinian corpuscle

Answer 21

Vibration and tickle

Deep dermis

Question 22

Describe the subcutis

Answer 22

Adipose tissue and fibrovascular septa

Insulation

Shock-absorber

Food store

Question 23

Where do ducts of the breast all empty

Answer 23

Nipple

Question 24

Are there histological differences between male and female breasts

Answer 24

Yes

Males breast tissue only is the ductal system

Question 25

What is the functional component of the breast

Answer 25

Terminal duct lobular

Lobules are arranged around a terminal duct

Set in loose fibrous connective tissue

Question 26

How can you tell is a breast is in lactation

Answer 26

Cells become vacuolated