Skin Flashcards
What is the superficial layer of the skin called?
Epidermis
What is in below the epidermis?
Dermis
What’s the Two major classes of skin?
1) hirsute- thin hairy skin (head(
2) glabrous- surface of palms
5 layers of epidermis:
1- stratum basale
2- stratum spinosum
3- stratum granulosum
4- stratum lucidum
5- stratum corneum
Features about stratum basale:
-deepest layer
-single layer of basal cells
-merkel cells
- melanocytes
Function of merkel cells
Responsible for stimulating sensory nerves (touch)
Melanocytes function
Produces melanin
Features of stratum spinosum
- provides strength and flexibility to the skin
-8 layers of keratinocytes formed due to cell division
Function of keratinocytes
Beings synthesis of keratin and water repelling glycolipid
Location and function of dendritic cells
Amongst keratinocytes
Functions as a macrophage
Features of stratum granulosum
Represents transition between active strata and dead superficial strata
Features of stratum lucidum
-smooth translucent layer
-keratinocytes dead and flattened
What is the function of keratin
Produced by keratinocytes
Protect the skin and tissues from heat and microbes
Features of stratum corneum
-most superficial epidermal layer
- provides a protective layer against light
- regular shedding of cells
What produces keratinocytes
Division of stem cells
What hormone helps in epidermal growth?
Epidermal growth factor
Features of the dermis
- touch and elastic due to connective tissue and collages fibres interlaced
- dermal cells (fibroblasts and macrophages)
- dermal structures ( blood vessels, nerve ending, sweat glands)
What is the meissners corpuscle
Light pressure skin receptor
What is the pack Ian corpuscle
Deep pressure skin receptor
Types of sweat glands
- eccrine
- apocrine
- sebaceous glands
Features of eccrine glands
-present on palms and soles of feet
- open watery substance
Features of apocrine glands
-sweat glands active during puberty
- mixes with bacteria on the skin (body odour)
Sebaceous glands features
-secretes into hair follicles
- waterproof barrier
- bactericial and fungicidal
Functions of the skin:
- protection
- excretion
- absorption
- regulation of body temperature
- formation of vitamin D
What does the skin offer protection from:
- invasion
- dehydration
- mild trauma
- chemicals
Four methods of heat loss
- convection
- conduction
- radiation
- evaporation
How is 7-dehydrocholesterol converted into vitamin D?
Sunlight
What products get absorbed by the skin
- nicotine
- chemicals
- chemotherapy
What causes aging
The skin and membrane become thin
-fewer capillaries and decrease in cell proliferation
- decrease in collagen
Three stages of wound healing
-inflammation
- proliferation
-maturation
What happens in inflammation
Surface becomes inflamed and a blood clot forms
What happens during proliferation
Epithelial cells proliferate across the wound
Clot above the tissue becomes a scab
What happens during maturation
Granulation tissue is replaced by scar tissue
What is a pressure ulcer?
When a large amount of pressure is applied to a region over a short amount of time
