skin

Question 1

epidermal appendages

Answer 1

hair follicles, nails, sweat glands, sebaceous glands

Question 2

epidermis

Answer 2

avascular component of the skin

keratinised, stratified squamous epithelium with basil laminar

Question 3

epidermal thickness

Answer 3

thick skin 1mm, thin skin 0.1mm

Question 4

5 strata of skin

Answer 4

1. stratum basale
2. stratum spinousum
3. stratum granulosum
4. stratum lucidum
5. stratum corneum

Question 5

stratum basale cells

Answer 5

columnar shaped epidermal stem cells

Question 6

stratum basale basal laminar

Answer 6

interfaces with the dermis

Question 7

rete ridge

Answer 7

epidermis invaginating into the dermis

Question 8

cells in stratum basal

Answer 8

melanocytes and Merkel cells

Question 9

Merkel cells

Answer 9

attach to non myelinated nerve ending, mechanoreceptor sensitive to light touch - mostly in thick skin

Question 10

melanocytes

Answer 10

have a space around them

Question 11

stratum spinosum cells

Answer 11

intracellular spinous cytoplasmic projections

Question 12

desmosomes

Answer 12

cell to cell adhesions, resistant to shear stress

Question 13

cells I stratum spinonosum

Answer 13

langerhans cells

- also present in papillary dermis

Question 14

langerhans cells

Answer 14

dendritic antigen presenting cells

Question 15

in stratum spinous, cell begin to

Answer 15

flatten and produce water proofing glycolipid - lammellar bodies
keratohyalin granules
and accumulate tonofilaments

Question 16

monofilaments

Answer 16

intracellular connector components

Question 17

stratum granulosum cells

Answer 17

squamous keratinocytes

2-3 layers

Question 18

what’s in stratum granulosum

Answer 18

more lamellar bodies and keratinohyaline granules

dehydrate the cells

Question 19

what happens at the stratum granulosum

Answer 19

cells begin to die

due to dehydration and not vascularised

Question 20

what happens when the cells die

Answer 20

lamellar Bodies are released, keratinohyaline granules fuse with monofilaments and form cross linked keratin

Question 21

keratin

Answer 21

tight water proof layer

UV protection and pH stabilisation

Question 22

stratum lucidum

Answer 22

only in thick skin
dead cell layer
several flattened cells thick and rich in eleidin

Question 23

eleidin

Answer 23

a lipid rich protein, gives the layer a lucid appearance

Question 24

stratum corneum

Answer 24

thick superficial layer, thicker in thick skin

Question 25

thick vs thin skin

Answer 25

``` corneum is thicker in thick skin only thick has stratum lucidum thick has no hair follicles thick has no sebaceous glands thick has pacinian (lamellar) corpuscles both have sweat glands ```

Question 26

papillary dermis

Answer 26

- loose irregular CT

Question 27

papillary skin

Answer 27

loose, irregular connective tissue | - loose so your skin can move around easily

Question 28

meissner's corpuscle

Answer 28

in dermis, modified nerve ending mechanoreceptor highest density thick skin like finger tips

Question 29

reticular skin

Answer 29

dense irregular connective tissue denser deposits of collagen and elastin fibres thicker than papillary dermis

Question 30

reticular skin houses

Answer 30

glands and roots of hair follicles from the epidermis

Question 31

kraissl lines

Answer 31

lines of tension | incisions parallel to these lines heal better

Question 32

subcutaneous tissue

Answer 32

subcutis/hypodermis from LP-m coiled secretory components from sweat glands nerves, vessels and capillaries in transit houses pacinian corpuscles

Question 33

pacinian corpuscles

Answer 33

large concentric rings of fibroblast cells separated by gelatinous fluid surrounding a nerve ending deep in the subcutis of thick skin only

Question 34

pacinian corpuscles detect

Answer 34

vibration | allows for sensation of textures

Question 35

melanocytes

Answer 35

sensitive to UV exposure | melanosomes are released

Question 36

melanosomes

Answer 36

absorbed by neighbouring cells blocks UV prevents DNA damage increases risk of vid D deficiency

Question 37

melanocyte density

Answer 37

equal across all humans

Question 38

types of melanin

Answer 38

eumelanin - brown and black | pheomelanin - yellow-red

Question 39

3 manners of secretion of glands

Answer 39

merocrine apocrine holocrine

Question 40

merocrine

Answer 40

exocrine gland that uses exocytosis

Question 41

apocrine

Answer 41

cell surface breaks off and moves away

Question 42

holocrine

Answer 42

whole cell is broken up in components

Question 43

2 types of sweat glands

Answer 43

merocrine and apocrine

Question 44

merocrine sweat glands

Answer 44

excrete sweat onto skin surface simple cuboidal/columnar with stratified cuboidal duct ductal cells capable to reabsorb electrolytes

Question 45

apocrine sweat glands

Answer 45

``` excrete in terminal hair follicles simple cuboidal/columnar milky because has a bit of fat in it larger lumens not thermoregulatory only found in terminal hair except for scalp ```

Question 46

holocrine glands example

Answer 46

``` sebaceous glands - excrete sebum (oily lipids) into hair follicles acing appearance (grapes) ```

Question 47

how sebaceous glands release sebum

Answer 47

cells closets to the duct explode, releasing sebum around the hair follicle

Question 48

vellus hair

Answer 48

wool/fleece

Question 49

terminal hair

Answer 49

on scalp | thicker

Question 50

hair shaft anchored at

Answer 50

root which has a bulb

Question 51

bulb

Answer 51

made up of epidermal stem cells

Question 52

bulb cell blood supply

Answer 52

from a papilla

Question 53

hair change during puberty

Answer 53

androgens convert vellus into terminal hair due to changes in blood supply

Question 54

hair as a sensory structure

Answer 54

nerve fibres surround hair and papilla

Question 55

erector pilli muscles

Answer 55

smooth muscle has autonomic control | sympathetic activation - contraction causes hair to stand on end