UNIT 3 - EPIDERMIS

Question 1

what are the characteristics of cutaneous membrane?

Answer 1

1. aids production of VIT D
2. supports removal of waste (sweat)
3. senses changes in env
   - nocireceptors pain
   - mechanoreceptors - pressure
   - Meissner corpuscle = fine touch

Question 2

what are the 2 layers of the skin?

Answer 2

1. epidermis = epithelial tissue

2. dermis = connective tissue

Question 3

where is there innervation and vascularisation?

Answer 3

innervation ( PACCINI CORPUSCLE) in the both epidermis and vascularisation (SUPERFICIAL + DEEP) only in the dermis

Question 4

what is in the hypodermis?

Answer 4

adipose tissue + areolar ct

Question 5

what is the epidermis?

Answer 5

Keratinized stratified squamous epithelium

Question 6

what is the dermis?

Answer 6

dense irregular CT

Question 7

what are the 4 different types of epidermal cells?

Answer 7

1. keratinocytes
2. merkel cells
3. melanocytes
4. langerhan cells

Question 8

characteristics of keratinocytes?

Answer 8

1. 90% in skin

2. continuous renewal - at different stages of development

Question 9

what do keratinocytes produce?

Answer 9

produce keratin = fibrous protein for abrasion and heat

+lamellae granuels

Question 10

characteristics of melanoocytes?

Answer 10

• 8% of cells
• develop in ectoderm
• produce melanin (color + UV)

Question 11

where are melanocytes found?

Answer 11

stratum basal or dermis

Question 12

what is 1. ectoderm

2. mesoderm
3. endoderm?

Answer 12

1. outer layer
2. middle
3. inner

Question 13

where are langerhan cells?

Answer 13

stratum spinosum

Question 14

where are merkel cells?

Answer 14

stratum basale

Question 15

how do melanin granules protect keratinocytes?

Answer 15

They shield the nuclear DNA from damage by UV

Question 16

what are MELANOSOMES?

Answer 16

melanin granules Transferred to keratinocytes by dendritic like extensions

Question 17

characteristics of langerhan cells?

Answer 17

1. 4% cells
2. dendritctic cell - imminuty
3. from BONE MARROW

Question 18

what are merkel cells?

Answer 18

• nerve terminals

- tactile sensations

Question 19

the 5 stratas in order= least deepest–> deepest

CLGSB

Answer 19

1. corneum
2. lucidum
3. granulosum
4. spinosum
5. basale

Question 20

skin grafts need a healthy what?

Answer 20

stratum basale

Question 21

stratum basale Is attached to wear?

Answer 21

1. monolayer of cuboidal cells attached to basement membrane by desmosomes

Question 22

what is function of stratum basale?

Answer 22

structural support

Question 23

characteristics of stratum spinosum=

Answer 23

1. 8-10 layers keratinocytes via desmosomes
2. in live skin round + big opposite in histological preps
3. strength + flex

Question 24

characteristics of GRANULOSUM?

Answer 24

1. 3/5 layers keratinocytes = apoptosis
2. prevents water loss via keratinocyte lamellae granules + microrg barrier
3. dark kertohyalin

Question 25

stratum lucidum charac=

Answer 25

1. . 3/5 layers no nucelus
2. . only palms, fingertips, soles
3. ALOT KERATIN

Question 26

stratum corneum characs=

Answer 26

1. 25/30 layers
2. continuous shredding
3. barrier light, bact, chems
4. friction = callus =abnormal thickening

Question 27

stratum basale characs=

Answer 27

1. high proliferation

2. ontop of basement membrane

Question 28

abrasions + burns inc mitotic rate where?

Answer 28

stratum basale

Question 29

how long does scaling + replacement take

Answer 29

2-3 weeks