LECTURE 2: anatomy of skin part 2

Question 1

sebaceous gland

Answer 1

produces sebum- natural moisturiser/water repellent

Question 2

5 accessory structures

Answer 2

1. hair
2. acne
3. sweat glands
4. receptors
5. nails

Question 3

hair as an accessory structure

Answer 3

located all over body (only prominent on head)

Question 4

what does hair consist of

Answer 4

hair shaft, hair follicle, arrector pili muscle, sebaceous gland

Question 5

acne as an accessory structure

Answer 5

blockage of hair follicles + infection

increased sebum increases acne risk

Question 6

sweat glands

Answer 6

eccrine and apocrine

Question 7

eccrine vs apocrine

Answer 7

eccrine (everywhere, thermoregulation)

apocrine (specialised): situated deeper in skin, release into base of hair follicle, oily

Question 8

receptors

Answer 8

• Tactile
• Lamellar
• Bulbous

Question 9

nails as an accessory structure

Answer 9

protects fingertips
Enhance sensation (sensory receptors requires deformation)

Question 10

what is melanin pigmentation

Answer 10

the melanin pigment absorbs UV light: protecting cells from UV damage

Question 11

what are melanocytes

Answer 11

where pigmentation is produced

Question 12

what are melanosomes

Answer 12

pigmentation transferred to epidermal cells by melanosomes which are vesicles containing melanin

Question 13

what is a mole

Answer 13

cluster of melanocytes

Question 14

what is overproliferation

Answer 14

can be caused by sun exposure

Question 15

what is a freckle

Answer 15

melanocytes overproducing melanosomes

Question 16

what is overproduction

Answer 16

triggered by sun exposure

Question 17

melanocytes are found…

Answer 17

in the stratum basale – (not shed)

Question 18

Melanosomes are found…

Answer 18

throughout the epidermis – (shed with keratinocytes)

Question 19

density of melanocytes…

Answer 19

varies throughout body but not between races

Question 20

why is vitamin D necessary

Answer 20

essential for normal calcium metabolism and strong bones – Vitamin D deficiency also affects mood

Question 21

vitamin D synthesis requires

Answer 21

UV exposure in skin

Question 22

what does UV exposure in skin explain about vitamin D synthesis

Answer 22

the greater incidence of lightly pigmented skin at higher latitudes

Question 23

what people are more susceptible to vitamin D deficiency?

Answer 23

highly pigmented people, particularly at extreme latitudes

Question 24

BASAL CELL CARCINOMA

Answer 24

Common but relatively benign

Originates in stratum basale

Metastasis is rare

Question 25

MALIGNANT MELANOMA

Answer 25

Rare but deadly if not treated

Originates in melanocytes (pigmented)

Highly metastatic

Mortality rate dependent upon tumour

Question 26

thickness of melanoma highly correlates with…

Answer 26

mortality rate

Question 27

what is a tattoo

Answer 27

Artificial pigmentation (usually ink) deposited deep within the skin: Dermal layer, ie. Not shed – captured (but not broken down) inside immune cells/scar tissue.

Question 28

what is a Lena tattoo

Answer 28

pigmentation of lymph nodes