Anatomy Chapter 5
bronzing
a golden brown skin color; deficiency of hormones from the adrenal gland, such as occurs with Addison disease
hair follicle
a sheath of epidermis surrounding each hair
keratin
a tough, fibrous protein that provides structural strength to the skin, hair and nails
erythema
abnormal redness; increased blood flow in dilated blood vessels close to the skin's surface; may result from heat, exercise, sunburn, or emotions such as embarrassment or anger
papilla
at the base of the hair is a cluster of connective tissue and blood vessels called: nourishes each hair
arrector pili muscle
attached to each hair follicle; small budle of smooth muscle; cold temperatures or fear cause the muscle to contract; the hair becomes upright "standing on end"
Subcutaneous
beneath the skin
cyanosis
blue tint to the skin; a deficiency of oxygen in circulating blood
bruise (hematoma)
bluish, black or yellowish mark on the skin; breakdown of clotted blood under the skin
eumelanin
brown-black type of melanin
bulb; root
buried in the dermis is the hair: where growth occurs; lowest part of hair
first-degree burn
burn that causes redness, slight swelling and pain
third-degree burn
burn that extends into the subcutaneous layer
first-degree burn
burn that involves only the epidermis
second-degree burn
burn that involves the epidermis and part of the dermis
second-degree burn
burn that may appear red, white or tan
third-degree burn
burn that may appear white or black and leathery
third-degree burn
burn that may not be painful intially; bc nerves are destroyed
second-degree burn
burn that may result in scarring
first-degree burn
burn that often results from sunlight (sunburn)
second-degree burn
burn that results in blisters, severe pain and swelling
keratinocytes
cells that replace the dead cells that flake away with daily wear
third-degree burn
complications: infection, fluid loss and lack of thermoregulation
dermis
composed of connective tissue; collagen fibers, elastin fibers, reticular fivers (bind collagen and elastin)
nails
consist of densely packed, heavily keratinized epithelial cells
stratum basale
consists of a layer of columnar stem cells that continually undergo mitosis to produce new skin cells
epidermis
consists of stratified squamous epithelial tissue
stratum corneum
consists of up to 30 layers of dead, flat, keratin-coated cells; makes skin's surface durable and resistant to abrasions
epidermis
contains no blood vessels
lunula
crescent-shaped white area at the base of the nail
eschar
dead tissue resulting from a burn
cerumen
ear wax
third-degree burn
eschar secretes toxins and promotes bacterial growth; can restrict circulation
sebum
has a mild antibacterial and antifungal effect
dermis
has an abundance of blood vessels
dermis
has sweat glands, sebaceous glands, nerve endings, and hair follicles
ceruminous gland
in the external ear canal that secretes waxy cerumen
nail bed
layer of epithelium under the nail; normally appears pink bc of the rich blood supply in the area
clubbing
long-term oxygen deficiency, usually due to lung disease; this causes the distal ends of the fingers to enlarge, making it look like a drumstick when viewed from above; at the same time the nail bed softens, causing the nail to angle downward, giving it a beaked appearance when viewed from the side
basal cell carcinoma
most common skin cancer; seldom metastasizes; least dangerous; arises from cells in the stratum basale; typically on nose or face; lesion first appears as a small, shiny bump as it enlarges, it often develops as a central depression and beaded "pearly" edge
malignant melanoma
most deadly of all skin cancers; sometimes develops from melanocytes of a preexisting moles; metastases quickly and is often fatal when not treated early; risk is greatest in individuals who had severe sunburns as children
newly keratinized cells
nails grow as________________ are added to the nail root from the nail matrix
keratin
new skin cells produce which tough fibrous protein?
hypodermis
not a true layer of skin tissue; made of areolar and adipose tissue; binds skin to underlying tissue
third-degree burn
often requires skin grafts
pallor
pale skin; decreased blood flow, such as occurs from cold temperatures, fear of emotion stress or low blood pressure
shaft
part of the hair that extends above the skin's surface
melanin
pigment produced by melanocytes that gives color to the hair and skin
sweat
plays a chief role in helping the body maintain a constant core temperature and also helps the body eliminate wastes
squamous cell carcinoma
skin cancer that arises on the epidermis and is slow growing; often occurs on the scalp, forehead, backs of the hands and top of the ears; has a raised, red, scaly appearance; some forms may metastasize
hypodermis
subcutaneous tissue composed mostly of fat lying under the dermis
nail body
the visible part of the nail
hypodermis
this layer of fat helps insulate the body from outside temperature changes; it also acts as an energy reservoir
asymmetry, border, color, diameter, evolving
ABC's of Skin Cancer
acne
Inflammation of the sebaceous glands, esp. during puberty, in which the follicle becomes blocked with keratinocytes and sebum. Whiteheads, blackheads, and pimples
dermatitis
Inflammation of the skin characterized by itching and redness, often the result of exposure to chemicals or toxins
psoriasis
A recurring skin disorder characterized by red papules and scaly silvery plaques with sharply defined borders.
urticaria
Allergic reaction resulting in multiple red patches that are intensely itchy
tinea
Any fungal infection of the skin; usually occurs in moist areas such as the groin, axilla, and foot
sebaceous glands
glands where production of sebum increases during adolescense; when excess sebum accumulates in the gland ducts, pimples and blackheads can form
impetigo
Contagious bacterial infection of the skin (usually caused by strep or staph), producing yellow to red weeping, crusted or pustular lesions around the nose, mouth, or cheeks or on the extremities.
eczema
Itchy, red rash caused by an allergy; lesions initially weep or ooze serum and may become crusted, thickened or scaly
papillae
_____ extend upward from dermis, where it interlocks with downward waves protecting from the bottom of the epidermis
alopecia
excessive hair loss
albinism
extremely pale skin, white hair, and pink eyes; a genetic lack of melanin
protection, barrier, vitamin d production, sensory perception, thermoregulation
five key functions of the skin
cuticle
fold of skin surrounds the nail body
stratum corneum
forms and effective barrier preventing water from entering the body from the outside whereas still allowing for evaporation
sensory perception
function of the skin; contains millions of ______ nerve fibers, allowing for perception of temp, touch, pressure, pain and vibration
Thermoregulation
function of the skin; contains nerves that cause blood vessels in the skin to dilate or constrict to regulate heat loss; when chilled, the skin retains heat by constricting blood vessels; this reduces blood flow through the skin and conserves heat; when overheated, the blood vessels in the skin dilate; this increases the flow of blood and increases heat loss; if the body is still overheated, the brain stimulates sweating, as sweat evaporates, cooling occurs
Vitamin D production
function of the skin; initiates the ___________________ when exposed to UV light
barrier
function of the skin; keeps the body from absorbing excess water; prevents dehydration by regulating the volume and content of fluid lost from the body; blocks UV radiation, keeping it from reaching deeper tissue
protection
function of the skin; prevents microorganisms and chemicals from invading the body; secretes a residue that helps block toxins and inhibit bacterial and fungal growth; absorbs the force of injuries, protecting delicate underlying structures
apocrine glands
glands located mainly in axillary and anogenital areas that secrete sweat in response to stress and sexual stimulation
eccrine glands
glands located throughout the body that secrete sweat directly onto the skin's surface, which helps control body temperature
eccrine glands
glands that are widespread throughout the body and are especially abundant on the palms, soles, forehead and upper torso
apocrine glands
glands that begin to function at puberty; located mainly in axillary and anogenital (groin) regions
eccrine glands
glands that contain a duct that leads from the secretory portion to the skin's surface
apocrine glands
glands that contain a duct that leads to a hair follicle; these are scent glands that respond to stress and sexual stimulation
sebaceous glands
glands that open into hair follicle; secrete an oily substance called sebum; helps skin and hair from drying out and becoming brittle
eccrine glands
glands that produce sweat, which contains potassium, ammonia, lactic acid, uric acid, and other wastes
sebaceous glands
glands that secrete an oily substance called sebum into each hair follicle
melanocytes
produces melanin
melanin
protects the nucleus from ultraviolet exposure
pheomelanin
reddish type of melanin
hair follicle
rich nerve and blood supply; each hair lies within a sheath of epidermis called:
apocrine glands
sweat produced by these glands does not have a strong odor unless it accumulates on the skin; when this occurs, bacteria begins to degrade substances in the sweat, resulting in body odor
stratum basale
the innermost layer of the epidermis, where new skin cells are germinated
the skin and all of its appendages (hair, nails, and skin glands)
the integumentary system includes:
dermis
the layer of skin lying immediately under the epidermis
sweat glands
the most numerous of the skin glands
stratum corneum
the outermost layer of the epidermis, consisting of dead, flattened cells called keratinocytes
epidermis
the outermost layer of the skin
nail root
the proximal end of the nail; it's hidden underneath overlying tissue
cutaneous
the skin is also called the _________ membrane
eccrine and apocrine
two types of sweat glands
basal layer
what layer of the epidermis are melanocytes scattered through
eccrine glands
which glands secrete sweat onto the skin's surface?
jaundice
yellow discoloration of skin and the whites of eyes; impaired liver function that allows bile to accumulate, which stains the skin