Skin Physiology

Question 1

4 main skin fns

Answer 1

nerve sensation
radiation protection
physical barrier
injury repair

Question 2

3 skin layers

Answer 2

epidermis
dermis
subcutis

Question 3

4 layers of epidermis, superficial to deep

Answer 3

stratum corneum
stratum granulosum
stratum spinosum
stratum basale

Question 4

cell division occurs..

Answer 4

in the basal layer, keratinocytes start here and move up

Question 5

spinous layer fn

Answer 5

lots of desmosomal junctions causing spiny appearance, hold keratinocytes together

Question 6

granular layer fn

Answer 6

keratinocytes produce lipids, secrete into extracellular space to form water barrier in corneum

keeps water in skin

Question 7

fn of stratum corneum

Answer 7

barrier

made of desquamating keratinocytes, non nucleated cells

Question 8

filaggrin fn and dysfn

Answer 8

found in granular layer, retains water w/i keratinocytes

mutations cause atopic dermatitis and asthma

Question 9

3 cell types in epidermis

Answer 9

keratinocytes, melanocytes, langerhans cells

Question 10

keratinocyte fn

Answer 10

make up majority of cells, held together by desmosomes

Question 11

melanocyte location and fn

Answer 11

along basal layer, one for every 10 keratinocytes

produce melanin, transfer to basal layer keratinocytes

Question 12

contrast nevi and melanoma

Answer 12

nevi: moles, benign collection of melanocytes
melanoma: malignancy of melanocytes

Question 13

langerhans cell fn

Answer 13

dendritic cells in mid epidermis, afferent limb of immune response- present antigens to T cells

key for delayed type hypersensitivity (play a role in contact dermatitis)

Question 14

two layers of dermis

Answer 14

papillary- envaginated epidermis

reticular- below papillary

Question 15

contents of dermis

Answer 15

blood/lymphatics/nerves

sweat glands and hair follicles

Question 16

cells of dermis

Answer 16

fibroblasts (keloids) and mast cells (immediate type hypersensitivity, major effector in urticaria)

Question 17

subcutis fn

Answer 17

fat layer, separates dermis from fascia and muscles

insulation, energy supply, cushion, mobility

Question 18

erythema nodosum is a disorder of…

Answer 18

subcutis inflammation, typically on shins

Question 19

components of pilosebaceous unit

Answer 19

hair follicle
sebaceous oil gland
apocrine sweat gland
arrector pili muscle

Question 20

acne vulgaris is disorder of

Answer 20

pilosebaceous unit: plugging of follicle, bacteria causes inflammation, hormones contribute, sebaceous gland activity

Question 21

eccrine glands are

Answer 21

open directly onto skin surface, throughout the body

not involved w/ hair follicles, regulate body temp w/ sweat excretion