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