skin and its accessory structures make up the ____
function of integumentary system: homeostatic control of body temperature due to release of sweat, and flow of blood in dermis
function of integumentary system: include touch, pressure, vibration, tickle, heat, cold, and pain.
transdermal drug administration
function of integumentary system: method of hydrophobic drug passage across epidermis and into blood vessels. Ex) hormones, contraceptives
synthesis of Vitamin D
function of integumentary system when UV light stimulates cells to convert a steroid into Vit D3, which is used to synthesis the hormone calcitrol
storage of nutrients
function of integumentary system when adipose tissue in the dermis and subcutaneous layer store fat soluble vitamins
medical speciality dealing with diagnosing and treating skin disorders
superficial portion of skin composed of epithelial tissue and is avascular
primarily composed of connective tissue such as collagen, elastin, and nerve endings
hypodermis that is below the dermis
not part of integumentary system; stabilizes skin as fat storage area, area for blood vessels, and area of pressure nerve endings
composed of stratified squamous epithelium/ contains four types of cells: keratinocytes, melanocytes, Langerhans cells, and Merkel cells
produce protein keratin which helps protect skin the underlying tissue from heat, microbes, and chemicals, and lamellar granules which release water resistant sealant
produce pigment melanin, contributes to skin color, and absorbs damaging UV light
these cells participate in immune responses to attack cancerous cells as well as pathogens that manage to penetrate the skin
cells that are sensitive to touch and release chemicals that stimulate a sensory structure called a tactile Merkel disc
most superficial layer, consists of 15-30 layers of dead keratinized cells.
these are in the stratum corneum and make the layer water repellant.
when water from inside the body slowly penetrates the surface of the stratum corneum and evaporates. (lose approximately 500mL/day)
abnormal thickening of the epidermis
layer of skin only present in thick skin on fingers, palms, and soles. contains keratinized cells.
these increase friction for better grasping and provide the basis for fingerprints. they fit together with the dermal papillae of the dermis
layer that marks the transition between the deeper, metabolically active strata and dead cells of superficial strata. has a high concentration of keratinocytes
process of replacing cell contents with the protein keratin
layer that provides strength and flexibility to the skin. Contains Langerhan cells
stratum basale (germinativum)
deepest layer of epidermis. contains some stem cells. forms new cells
this is needed when the germinal portion of the epidermis is destroyed.
fastest growing form of cancer
This is due to epidermal pigmentation and dermal circulation
produces brown, yellow-brown, black pigment stimulated by UV light
inherited inability of an individual to produce melanin
orange-yellow pigment that accumulates in epidermal cells. Contained in carrots, squashes, sweet potatoes
contained in erythrocytes and provides color to the skin
sustained reduction of blood supply causes blue nail beds and lips
yellowish whites of eyes and skin due to build up of billirubin
this layer lies between the epidermis and subcutaneous layers; is composed of connective tissue containing collagen and elastic fibers. Has TWO regions.
layer of the dermis: is loose areolar connective tissue containing fine elastic fibers, dermal papillae, corpuscles of touch, and free nerve endings
layer of dermis: consists of dense, irregular connective tissue containing bundles of collagen fibers and some elastic fibers.
branching networks of arteries for dermal circulation
caused by a constant deficiency of blood to tissues overlying a bony projection that has been subjected to prolonged pressure (decubitus ulcers)
inflammation of the dermis due to infection, allergy, etc.
a chronic skin disorder characterized by a more rapid division and movement of keratinocytes through the epidermal strata. NOT an inflammatory condition
fluid accumulation due to damage to connections between the superficial and deep layers of epidermis or epidermis and dermis
variety of pigment patterns, a high concentration of pigment, usually a concentration of blood vessels
hairs or pili
an accessory structure present on most skin surfaces except for palms, digits, soles.
part of hair that we can see
this anchors hair in the dermis
this is the organ that the hair is produced in
outer surface of the hair shaft
smooth muscle that contracts to make hair stand erect when body is cold or scared. attached to hair
this is due primarily to the amount and type of melanin (genetically determined)
sebaceous (oil) glands
these are usually connected to hair follicles; they are absent in palms and soles; produce sebum
sudoriferous (sweat) glands
divided into two types of sweat glands
eccrine (merocrine) sweat glands
sweat glands that have an extensive distribution; ducts terminate at the pores at the surface of epidermis. FUNCTION: regulate body temperature & eliminate wastes like NaCl and urea
apocrine sweat glands
sweat glands that are limited in distribution to skin of the axilla, pubis, and areola. Ducts open into hair follicles. Produce secretions that play a role in sexual attraction and reproduction
modified sudoriferous glands that produce a waxy substance called cerumen
hard, keratinized epidermal cells over the dorsal surfaces of the terminal portions of the fingers and toes. Provides protection against trauma to ends of digits
this can be caused by excessive exposure to sunlight. Most predominant kind of cancer
basal cell carcinoma
cancer of stratum basale that rarely metastasizes
squamous cell carcinoma
cancer of epidermis that rarely metastasizes
melanocytes are close to blood vessels and lymph so are likely to metastasize
tissue damage from excessive heat, electricity, radioactivity, or corrosive chemicals that destroys or denatures proteins in the exposed cells
(partial thickness effected) only superficial epidermis is damaged and cells can be replaced
(partial thickness effected) entire epidermis and some dermis are damaged and cells can be replaced (blisters and swelling). Hair follicles and glands usually not affected. May have some scar tissue
(full-thickness effected) entire epidermis and dermis are damaged and no integumentary tissue is left. Accessory structures (hair and glands) are destroyed. Grafts must be used. These are less painful because because pain sensory nerves in dermis are destroyed
each limb is 9% of total body surface area
both arms burned is ___%
trunk/torso front and back is ____%
one leg is ___%
most of the effects of this do not occur until an individual reaches late 40's.
effect of skin aging: lose collagen and reticulum fibers
effect of skin aging: color changes, lose ability to produce melanin. forms air pockets in the shaft
decreased Langerhans cells
effect of skin aging: decreased immune responsiveness, wounds take longer to heal.
decreased vitamin D3 production
effect of skin aging: decreased calcium and phosphate absorption resulting in weaker bones and muscles
epidermal growth factor
stimulates basal cells to divide and replace ones that have moved into the wound. (initiate of wound healing)
pigment goes deep into dermis, inflicting damage into the dermis. Transparent dermis grows over ink