Lecture 6- Skin biology Flashcards
1
Q
Functions of the skin
A
- Protective against environmental insults
- Temp regulation
- Sensation
- Vit D synthesis
- Immunosurveillance
- Cosmesis
2
Q
three main layers of the skin
A
Epidermis, dermis and hypodermis
3
Q
Epidermis
- 4 major cell types- each with individual function
A
- Keratinocytes- protective barrier
- Langerhans- APCs
- Melanocytes- produce melanin which provides pigment to the skin and protects cell nuclei from UV DNA damage
- Merkel cells- contain specialised nerve endings for sensation
4
Q
layers of the epidermis
A
“Come Lets Get Some Beers”
- Each layer represents a different stage of maturation of keratinocytes
- Stratum Basale
- Stratum spinosum
- Stratum granulosum
- Stratum corneum
Extra layer = stratum
5
Q
extra layer of epidermis found in areas of thicker skin e.g. palms and soles
A
stratum lucidum
6
Q
Average epidermal turnover=
A
30 days
- Some conditions have much higher turnover = psoriasis
7
Q
pathology of the epidermis may cause
A
- change in epidermal turnover
- change in surface of the skin
- changes in pigmentation of the skin
8
Q
epidermal pathology examples
A
- stable plaque psoriasis
- vitiligo
9
Q
Stable plaque psoriasis
A
Typically found on torso, back of leg, extensor surfaces
10
Q
Vitiligo
A
- Autoimmne condition leading to depigmentation
- Hypopigmentation (partial loss) or depigmentation (complete loss of pigmentation)
11
Q
function of the dermis
A
- The cushion
- Composed of collagen, elastin and glycosaminoglycans
- Provides strength and elasticity
12
Q
what does the dermis contain
A
- Immune cells
- Nerve cells
- Skin appendages
- Lymphatics
- Blood vessels
- hair
- glands
- sebaceious
- eccrine and apocrine (found at the border of the hypo and dermis)
13
Q
Sebaceous glands
A
- Produce sebum through hair follicles (pilosebaceous unit)
- Secretes sebum on to skin which lubricates skin
- Active after puberty
- Stimulated by conversion of androgen to dihydrotestosterone
- Increased sebum production and bacterial colonisation in conditions such as:
Acne vulgaris
14
Q
sweat glands
A
- Sweat glands
- Regulate body temp
- Innervated by sympathetic system
- Two types: eccrine and apocrine
15
Q
eccrine sweat glands are found
A
widespread