Lecture 19

Question 1

Where is the adipose tissue located in the skin?

Answer 1

Hypodermis

Question 2

Skin layers?

Answer 2

Epidermis

Dermis- hair follicles, sebaceous glands etc

Hypodermis- adipose tissue…. hypodermis also known as sub cutaneous layer and injections are given here

Question 3

Hypodermis function?

Answer 3

Insulation
Energy store
Shock absorber
Makes hormones

Question 4

Dermis function?

Answer 4

Sweat glands and hair follicles

Gives structure to skin and so body shape

Question 5

Epidermis function?

Answer 5

Four layers of cells and 5 layers in thick skin. No blood vessels.

Prevents water loss
Prevents pathogen ingress makes keratin
Regents tissue loss from abrasion

Question 6

Stratum corneum layer?

Answer 6

Contain keratin

Thick on palms and soles of feet

Question 7

Stratum granulosum layer?

Answer 7

Stratified squamous

Makes keratin

Question 8

Stratum spinosum?

Answer 8

Cuboidal epithelium

Question 9

Stratum basale or basal cell layer?

Answer 9

Columnar cells
Renew keratinocytes
Where melanocytes found

Question 10

What causes psoriasis?

Answer 10

Keratin synthesised by keratinocytes. Transit type to surface (stratum corneum) usually 28-40 days but in psoriasis is 2-3 days. Results in silvery scales

Question 11

What are the important cells of the epidermis?

Answer 11

Melanocytes- produce melanin, don’t increase in number in black or tanned skin

Langerhans cells- present antigens to T lymphocytes= immune response

Merkel cells-mechanoreceptors responsible for touch

Question 12

What are the two skin types?

Answer 12

Hairy or think skin and non hairy or thick skin

Lips and parts of genitalia are exceptions

Main differences are just sweat glands and hair follicles

Question 13

What are the three types of hair?

Answer 13

Lanugo- covers foetus

Vellus- replaces lanugo eg back of hands

Terminal- thick hair on scalp and nasal passageway etc

Question 14

Functions of hair?

Answer 14

Thermoregulation

Sexual attraction- pheromones and hair style

Sensation- sensory nerve endings within the bulb

Protection- eg eyelashes

Question 15

What makes hair stand up?

Answer 15

The arrector pili muscle

Question 16

What mechanoreceptors can be found in the skin?

Answer 16

End bulbs- thermoreceptors

Free nerve endings- have nociceptors which register pain

Tactile discs- sense touch, pressure and texture

Ruffini’s corpuscle- joint movements and tissue stretch

Root hair plexus- vibrations in hair shaft

Question 17

What about nails?

Answer 17

Found on distal surface of pharanges

Enhances fingertip sensitivity

Enhances precise delicate movements

Protects distal phalanx

Finger nail growth is correlated to length of pharynx

Question 18

What protects against UV?

Answer 18

Melanocytes

Question 19

Skin functions summary?

Answer 19

Protection and repair

Thermoregulation

Sensation

Absorption

Storage

Vitamin D synthesis

Lubrication

Aesthetics

Question 20

What skin condition can be caused by vitamin A deficiency?

Answer 20

Hyperkeratosis- abnormal thickening of outer skin layer (keratin layer)