Skin Flashcards
What is the integumentary system
skin and other keratinous substances
How much of your body weight is skin
5-10%
What are the layers of skin
Epidermis, dermis, hypodermis
What are the strata of the epidermis
Basale, spinosum, granulosum, lucidum, corneum
Is the epidermis avascular?
Yes
What cells are in the epidermis
Melanocytes, dendritic cells and tactile cells
What is the skin classified as in term of epithelial cells
Stratidies squameous epithelium
What is the stratum baSALE
cONTinuously mitosic cells. Basement membrane
What is the stratum spinosum
Pre keratin filament
What is stratum granulosum
layer where keratination begins
What is lucidum layer
Layer where there are dead cells in thick skin
What is corneum
Layer where cells shed
How long does it take for epidermal cells to replace themselves
25 days to 8 weeks
What is dermis composed of
Composed of connective tissue and contains blood vessels
What does papillary layer compose of
Capillaries, nerve endings
What is the reticular layer compose of
Dense connective tissue, sebaceous and sweat glands produce hair follicles
What is the hypodermis composed of
Fat, primary purpose to store energy
what are flecure lines
dermal folds
what is striae
stretch marks
what is a blister
fluid filled pocket
What pigments contribute to skin colour
Melanin, carotene, haemoglobin
What triggers melanocytes
UV
What types of melanin are there
Eumelanin (black ppl)
Pheomelanin (white ppl)
Where is carotene from
Carrots
what affect does carotene have on your skin colour
Orange
How does hair work
An extension of the epidermis which comes from the hair root
what types of hair are there
vallus and terminal
what is vallus hair
Thin hair
what is terminal hair
thick hair
what is the function of the piloerector muscle
Used for goosebumps
how do nails work
Produced from the nail root, becomes keratinised and forms a thick form of keratin
how does the mericrine gland work
Secretes using exocytosis, through sweat
How soes the apocrine work
Part of cell explodes. makes it smelly via bacteria. Do not play a thermoregulatory role. Mostly in armpits. Sweat has fat in it
How does the holocrine gland work
The cell explodes producing sebum (oily lipids) into hair follicle
What are the functions of skin
Absorption, protection, sense organ, thermoregulation, communication, vitamin production, excretion
How does skin protect
Low PH retards multiplication of bacteria. Keratin blocks water. Dendritic cell recognise foreign antigen
What absorbs in the skin
Vitamins, drugs, gases (O2 and CO2)
How does skin function sensory
Thermoregulation, touch, pain
How does skin thermoregulate
Temp regulates theough sweat and blood vessel vasodilation and vasoconstruction
How does sensible perspiration work
Temps above 32 degrees you sweat
How does insensible perspiration work
random water loss
how does communication work
sensort receptors communicate to the CNS
How does skin produce vitamins
UV synthesises vitamin D
