The Skin Flashcards
What are the functions of the skin
protection, temperature maintenance, sensory reception
How many layers does the skin have
3
What are the three layers of the skin
dermis, epidermis, hypodermis
What are the accessory structures in the skin
glands, hair, nails
What are the two types of skin
thick, thin
How many layers in thick skin
5
How many layers in thin skin
4
Where is thick skin found
palms, feet
Describe the epidermis
stratified, squamous, keratinised epithelium
Where are keratinocytes born
lower layer of epidermis
What are the five layers of the epidermis
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
What is the deepest layer of the epidermis
stratum basale
What is the stratum basale anchored onto
basement membrane
What separates stratum basale from underlying dermis
basement membrane
What is the main cell type in stratum basale
keratinocytes
What cell types are located in the stratum basale
keratinocytes, melanocytes, tactile cells
Describe the keratinocytes in stratum basale
highly proliferative
What do melanocytes produce
melanin pigment
What are the two types of melanin
eumelanin, pheomelanin
What is the thickest layer of epidermis
stratum spinosum
Describe the keratinocytes in the stratum spinosum
flattened shape, produce keratin, detached from BM
What are the two cell types in stratum spinosum
keratinocytes, dendritic cells - langerhans
What is the function of langerhans - dendritic cells
fight infection
What is the last layer of epidermis to have live cells
stratum granulosum
What is present in the stratum granulosum
glycolipids, keratinocytes
What is the function of glycolipids in stratum granulosum
water resistant layer
Describe the keratinocytes in the stratum granulosum
post-mitotic
What does keratin form in stratum granulosum
durable filaments - elasticity
What does stratum lucidum only exist in
thick skin
What is the appearance of stratum lucidum
translucent
What is the most superficial layer of skin
stratum corneum
Describe the composition of the stratum corneum
high lipid content, dead cells
How do keratinocytes migrate
travel upwards, die in most superficial layer
What do keratinocytes produce
keratin
What are the two layers of the dermis
papillary layer, reticular layer
TRUE or FALSE - the dermis has a regular shape
FALSE
How is the dermis attached to the epidermis
anchored through papillary layer
Describe the papillary layer
superficial, in contact with epidermis
What is the papillary layer made of
connective tissue
Describe the reticular layer
irregular
What is the reticular layer made of
dense connective tissue rich in collagen
What is the function of the reticular layer
protects internal organs
What does the reticular layer contain
accessory structures, blood vessels, muscles, sensory nerves
What is the deepest layer of the skin
hypodermis
What does the hypodermis consist of
fat cells - adipocytes
What is the function of the hypodermis
protect against heat loss
What are some cutaneous glands
mammary glands, ceruminous glands, sweat glands
What causes acne
excess sebum
What are the two types of sweat glands
apocrine, merocrine
Where are apocrine glands present
armpits
What is the function of apocrine glands
secrete sweat
Describe the merocrine glands
have a duct that directly secretes into the skin
What are the functions of the merocrine glands
responsible for perspiration, thermoregulation
What are the functions of the skin as a barrier
prevents infection and entry, biochemical barrier, immunological barrier
How is vitamin D3 made
sun
What is required for synthesis of provitamin D3
UV
Where does provitamin D3 travel to
liver
What does vitamin D3 act as
transcription factor
What is the function of vitamin D3
anti-tumour proliferation, blocks proliferation
