LECTURE 2: anatomy of skin part 2 Flashcards
sebaceous gland
produces sebum- natural moisturiser/water repellent
5 accessory structures
- hair
- acne
- sweat glands
- receptors
- nails
hair as an accessory structure
located all over body (only prominent on head)
what does hair consist of
hair shaft, hair follicle, arrector pili muscle, sebaceous gland
acne as an accessory structure
blockage of hair follicles + infection
increased sebum increases acne risk
sweat glands
eccrine and apocrine
eccrine vs apocrine
eccrine (everywhere, thermoregulation)
apocrine (specialised): situated deeper in skin, release into base of hair follicle, oily
receptors
- Tactile
- Lamellar
- Bulbous
nails as an accessory structure
protects fingertips Enhance sensation (sensory receptors requires deformation)
what is melanin pigmentation
the melanin pigment absorbs UV light: protecting cells from UV damage
what are melanocytes
where pigmentation is produced
what are melanosomes
pigmentation transferred to epidermal cells by melanosomes which are vesicles containing melanin
what is a mole
cluster of melanocytes
what is overproliferation
can be caused by sun exposure
what is a freckle
melanocytes overproducing melanosomes
what is overproduction
triggered by sun exposure
melanocytes are found…
in the stratum basale – (not shed)
Melanosomes are found…
throughout the epidermis – (shed with keratinocytes)
density of melanocytes…
varies throughout body but not between races
why is vitamin D necessary
essential for normal calcium metabolism and strong bones – Vitamin D deficiency also affects mood
vitamin D synthesis requires
UV exposure in skin
what does UV exposure in skin explain about vitamin D synthesis
the greater incidence of lightly pigmented skin at higher latitudes
what people are more susceptible to vitamin D deficiency?
highly pigmented people, particularly at extreme latitudes
BASAL CELL CARCINOMA
Common but relatively benign
Originates in stratum basale
Metastasis is rare
MALIGNANT MELANOMA
Rare but deadly if not treated
Originates in melanocytes (pigmented)
Highly metastatic
Mortality rate dependent upon tumour
thickness of melanoma highly correlates with…
mortality rate
what is a tattoo
Artificial pigmentation (usually ink) deposited deep within the skin: Dermal layer, ie. Not shed – captured (but not broken down) inside immune cells/scar tissue.
what is a Lena tattoo
pigmentation of lymph nodes
