HUBS192 Lecture 1 - Skin Anatomy of the Skin part I

Question 1

3 primary layers of the skin

Answer 1

1) epidermis
2) dermis
3) hypodermis

Question 2

epidermis

Answer 2

stratified squamous epithelium composed of mostly keratinocytes that has no circulation (avascular)

Question 3

what is the dermis composed of and what are the features of the dermis?

Answer 3

composed of protein fibres (collagen and elastin) for strength and is vascular (nourishes epidermis)
- not shed

Question 4

hypodermis

Answer 4

composed of adipose tissue

Question 5

cutaneous membrane

Answer 5

composed of the epidermis and the dermis

Question 6

subcutaneous membrane

Answer 6

composed of the hypodermis

Question 7

2 layers the dermis is composed of

Answer 7

1) papillary layer

2) reticular layer

Question 8

5 layers of the epidermis

Answer 8

1) stratum corneum
2) stratum lucidum (only found in ‘thick skin’)
3) stratum granulosum
4) stratum spinosum
5) stratum basale

Question 9

stratum corneum (horny layer)

Answer 9

composed of keratin, dead, dried-out hard cells without nuclei (most superficial layer)

Question 10

stratum granulosum (granular layer)

Answer 10

• contains granules that promote cell dehydration and cross-linking of keratin fibres
• waxy material is secreted into intercellular spaces

Question 11

stratum spinosum (spiny cell layer)

Answer 11

• desmosomes (intercellular bridges) link cells together

- cells become increasingly flattened as they move upward

Question 12

stratum basale (basal layer)

Answer 12

• columnar (tall) regenerative cells

- as the basal cell divides, a daughter cell migrates upwards, replenishing the above layer

Question 13

feature of the stratum corneum

Answer 13

can be completely removed by strip-taping

Question 14

function of the epidermis

Answer 14

to act a a keratinocyte conveyor

Question 15

main tissue type that dominates the epidermis

Answer 15

epithelial tissue

Question 16

3 types of simple epithelial cell types

Answer 16

1) simple epithelia squamous
2) simple epithelial cuboidal
3) simple epithelia columnar

Question 17

3 types of stratified epithelia

Answer 17

1) stratified epithelia squamous
2) stratified epithelia cuboidal
3) stratified epithelia columnar

Question 18

thick skin

Answer 18

• present of palms of hands and soles of feet
• no hair
• extra epidermal layer

Question 19

skin aging

Answer 19

• thin epidermis/ dermis because of reduced collagen
• slower skin repair
• drier epidermis (less sebum)
• impaired cooling (less sweat)
• less pigmentation

Question 20

how skin anatomy relates to skin ageing

Answer 20

as the skin ages, its functions are diminished therefore pigmentation is decreased

Question 21

relationship between stratum lucidem and ‘thick skin’

Answer 21

stratum lucidem is only found in ‘thick skin’

Question 22

composition of ‘thick skin’

Answer 22

‘thick skin’ has a large deposit of stratum corneum

Question 23

function of the reticular layer in the dermis

Answer 23

reticular layer helps give the dermis strength

Question 24

8 functions of the skin

Answer 24

1) protect underlying tissues and organs against impact, fluid loss and chemical attack
2) excrete salts, water and organic wastes by glands
3) maintain normal body temp through thermoregulation
4) produce melanin, which protects from UV radiation
5) produce keratin, which protects against abrasion and repells water
6) synthesises vitamin D3
7) stores lipids in adipocytes in the dermis and adipose tissue in the subcutaneous layer
8) detects stimuli and relays to the nervous system

Question 25

vitamin D3 function

Answer 25

steroid that is converted into calcitriol, a hormone important for normal calcium metabolism

Question 26

function of pigmentation

Answer 26

1) protection from UV radiation

2) vitamin D production