integumentary system Flashcards
what organs make up the integumentary system?
skin, hair, nails, sweat glands, sebaceous glands
what percent of body weight is skin?
12-15%
what are functions of skin?
1st barrier against infection and disease, and prevents fluid loss from organs
what are the functions of the integumentary system?
maintain internal temp (sweating and shivering), excrete excess fluid and waste, receive stimuli for pressure, pain, heat, and cold, produce and secrete melanin and vitamin D, protect body from infection, maintain fluid balance
what are the 3 main layers of skin?
epidermis, dermis, hypodermis
what are the layers of the strata in the dermis?
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
what cells make up the epidermis?
melanocytes, keratinocytes, merkel’s cells, langerhans’ cells
what is the function of melanocytes?
produce melanin
what is the function of keratinocytes?
produce keratin (makes up hair and nails)
what is the function of merkel’s cells?
feel touch
what is the function of langerhans’ cells?
cells that form immunity
since the epidermis is avascular, how does it get its nutrients?
get it when basement membrane of dermis diffuse below it
what is the function of the stratum basale?
single layer of cells on basement membrane of dermis that divide and push up towards surface of skin
what is the function of the stratum spinosum?
spiny cells pushed out of stratum basale that lock together to form a support layer
what is the function of the stratum granulosum?
living cells w/o nutrients that produce keratin and die. the keratin protein makes up most of dead cells in next two layers
what is the function of the stratum lucidum?
dead keratinized cells found in thick skin areas (souls of feet) not thin
what is the function of the stratum corneum?
outer layer we can see made out of dead keratinized cells. tightly bound together, and keratin protects underlying cells from fluid loss while keeping skin elastic. does desquamation
what is desquamation?
when cells of stratum corneum are sloughed off and cells from epidermis shed every 35-45 days, so then you have new skin every month and a half
what types of proteins make up the dermis?
collagen, elastin, and reticular fibers
what structures can be found embedded in the dermis?
blood vessels, glands, hair follicles, and nerves
what is the function of sweat glands?
assist body in temp control
what is the function of sebaceous glands?
produce oils that keep outer layer of skin and hair moisturized
what are hair and nails made of?
highly keratinized epithelial cells
what is a skin biopsy, and what does it diagnose?
skin is removed and examined microscopically, diagnoses cancer or abnormal skin growth
what is a patch test, and what does it diagnose?
allergens are applied to skin to see what you are allergic to, diagnoses allergies leading to skin disorders
what is a skin culture, and what does it diagnose?
take sample of skin and let it grow, diagnoses bacterial, fungal, or viral infection
