Chapter 3 all

dermatology

medical specialty that studies the anatomy and physiology of the skin

integumentary

pertaining to the skin or body covering

cutaneous

pertaining to the skin

epidermal

pertaining to the thin, outermost layer of skin

dermal

pertaining to the thick, connective layer of skin beneath the epidermis

melanocyte

a black-pigmented cell that produces melanin to absorb UV light

piloerection

action or condition of a hair standing up, causing a goosebump

subcutaneous (sub Q / subcu)

pertaining to the loose, fatty connective tissue layer below the dermis

lipocyte

a fat cell found within the subcutaneous tissue layer

dermatitis

infection or inflammation of the skin layer

hemorrhage

excessive discharge or flow of blood into the skin from ruptured vessels

neoplasm

a new, abnormal growth of benign or malignant tissue on the skin

xeroderma

excessive dryness of the skin layer

cyanosis

abnormal process or condition of bluish-purple skin discoloration from oxygen deficiency

necrosis

abnormal condition of gray-to-black skin discoloration where tissue cells have died

cyst

elevated circular skin mound with skin color or erythema, filled with semisolid or partly fluid material

fissure

small, cracklike crevice with erythema and no fluid exudate; example includes dry, chapped skin

macule

flat circle with pigmented brown or black coloration containing no internal fluid; example includes a freckle

papule

elevated solid lesion with skin color or erythema; example includes an acne pimple

pustule

elevated lesion with a white top containing pus; example includes an acne whitehead

scale

flat to slightly elevated thin white flake containing no internal fluid; examples include dandruff and psoriasis

vesicle

elevated lesion with a pointed, transparent top containing clear fluid; examples include herpes, chickenpox, and shingles

wheal

elevated lesion with a broad, flat, pale top surrounded by erythema and containing clear fluid; examples include insect bites and urticaria

Dermatology

Medical specialty that studies the anatomy and physiology of the integumentary system

Integumentary System

The body system consisting of the skin, nails, and subcutaneous tissue

Skin

The largest organ in the human body, consisting of the epidermis and dermis layers

Epidermis

The thin, outermost layer of the skin made up of epithelial tissues

Dermis

The thick layer of skin lying below the epidermis made up of connective tissue

Squamous Layer

The upper part of the epidermis composed of both living and dead cells

Keratin

A fibrous protein found in epidermal cells that makes the skin waterproof and strong

Exfoliation

The continuous process of shedding dead skin cells from the skin surface

Basal Layer

The deep part of the epidermis composed of living cells that constantly divide

Melanocytes

Cells in the epidermis that produce the pigment melanin to absorb UV light

Melanin

The dark pigment produced by melanocytes that colors the skin and hair

Collagen

Firm, white proteins within the connective tissue of the dermis providing structural support

Elastin

Elastic, yellow proteins within the dermis layer providing skin flexibility

Dermatome

An area of skin that sends sensory information to a nerve in the spinal cord

Sebaceous Glands

Exocrine oil glands in the dermis that produce a moisturizing oil called sebum

Sebum

The oily secretion produced by sebaceous glands that coats and moisturizes the skin and hair

Sudoriferous Glands

Exocrine sweat glands that secrete sweat through a duct to a skin pore

Sweat

An odorless, watery secretion containing sodium and small amounts of body waste

Hair Follicle

A structural cavity in the dermis layer where an individual hair forms

Piloerection

The action of a hair standing up to cause a goosebump when the skin is cold

Nail Plate

The hard, flat protective part of the nail composed of hardened dead cells

Nail Root

The structure located under the skin on the upper finger surface that produces living nail cells

Lunula

The white, half-moon-shaped area located at the base of the fingernail

Cuticle

The protective tissue edge surrounding the base of the nail

Nail Bed

The pink vascular tissue layer that lies directly under the nail plate

Subcutaneous Tissue

Loose, connective adipose (fatty) tissue located directly beneath the dermis layer

Lipocytes

Fat cells found within the subcutaneous tissue layer

Thermoregulation

The process of controlling, adjusting, and maintaining a stable body temperature

Homeostasis

The biological process of maintaining balance and stability across body systems

Dermatitis

Any infection or inflammation of the skin layer

Edema

Excessive amounts of fluid moving from blood into the dermis or subcutaneous tissue causing swelling

Pitting Edema

Severe swelling where fingertip pressure leaves a deep, persistent indentation in the tissue

Hemorrhage

An injury to the blood vessels that releases blood directly into the skin

Lesion

Any observable damage, injury, or structural variation from normal healthy skin

Neoplasm

Any new, abnormal skin growth that can be either benign or malignant

Pruritus

An intense itching sensation caused by the release of histamine during an allergic reaction

Rash

Any temporary pink, red, purplish, or darkened skin lesion that may be flat, raised, or itchy

Xeroderma

A medical condition characterized by excessive dryness of the skin

Albinism

A genetic mutation causing a complete lack of pigment in skin, hair, and the eyes

Cyanosis

A bluish-purple discoloration of the skin and nails indicating a lack of oxygen

Erythema

A localized or widespread red discoloration of the skin layer

Jaundice

A yellowish discoloration of the skin, palms, soles, or whites of the eyes

Necrosis

A gray-to-black skin discoloration occurring in areas where tissue cells have died

Vitiligo

A progressive autoimmune disorder where melanocytes are slowly destroyed, causing white patches

Abrasion

A sliding or scraping injury that mechanically strips away the epidermal layer

Blister

A fluid-filled sac formed when repetitive rubbing separates the epidermis from the dermis

Burns

Skin damage to the epidermal or dermal layers caused by heat, electricity, chemicals, or radiation

Superficial Burn

A first-degree burn involving only the epidermis, causing redness, pain, and swelling

Full-thickness Burn

A third-degree burn destroying the epidermis, dermis, and sometimes sub Q tissue or muscle

Rule of Nines

A clinical tool used to estimate the total percentage of a burn over the body surface

Callus

A wide, elevated pad of thickened epidermis caused by a repetitive rubbing injury

Cicatrix

A healing scar composed of a fibrous mesh of collagen tissue

Excoriation

A superficial linear scratch on the skin made by a sharp object like a fingernail or thorn

Keloid

A firm, abnormally large scar that grows past the original injury due to overproduced collagen