BIOL 216 Integumentary System

alopecia

hair loss or baldness

androgenic alopecia

hair loss caused by genetic and hormonal factors; commonly called male/female pattern baldness

cutaneous

relating to the skin

cuticle

the thin outer layer of a hair or nail

daughter cell

a new cell produced when a parent cell divides

dermal

relating to the dermis, the deeper layer of skin

dermal papillae

small projections of the dermis that extend into the epidermis; contain blood vessels and help form dermal ridges

dermal ridges

ridges formed by the dermal papillae that create fingerprints and improve grip

dermis

the deeper layer of skin beneath the epidermis; contains blood vessels, nerves, glands, and hair follicles

eccrine gland

a sweat gland that produces watery sweat to help cool the body

eczema

a condition causing inflamed, itchy, irritated skin

epidermal ridges

ridges of the epidermis that interlock with dermal papillae and form fingerprints

eponychium

the cuticle of the nail; the skin overlapping the base of the nail

granular cells

cells in the stratum granulosum that contain keratin granules and help form keratin

hair follicle

a tube-like structure in the skin where a hair grows

hair root

the portion of a hair below the skin surface, inside the follicle

hair shaft

the portion of the hair that extends above the skin’s surface

integument

the skin and its accessory structures, including hair, nails, and glands

keratin

a tough, water-resistant protein found in the skin, hair and nails

keratinocyte

most common epidermal cell that produces keratin

lamellated (Pacinian) corpuscle

a sensory receptor that detects deep pressure and vibration

langerhans cell

an immune cell in the epidermis that helps detect and fight pathogens

lunula

the whitish, crescent-shaped area at the base of the fingernail

matrix

the growth region of a hair or nail where cells rapidly divide to produce new cells

medulla

the innermost layer of a hair

melanin

a pigment that gives skin, hair, and eyes their color and helps protect skin from UV radiation

melanocyte

a cell that produces melanin

melanosome

a small organelle in a melanocyte that stores and transports melanin

merocrine

a type of secretion in which substances are released from a cell by exocytosis, without damaging the cell

nail blanch/capillary refill test

pressing the nail until it turns white, then releasing in; normal color should return quickly, a sign of blood flow to the tissue

nevus/mole

a localized collection of pigment-producing cells that creates a small colored spot on the skin

palmoplantar

relating to the palms of the hands and soles of the feet

papillary layer

the superficial layer of the dermis; contains dermal papillae, capillaries, and sensory receptors

psoriasis

a chronic condition in which skin cells are produced too quickly, causing thick, scaly, and inflamed patches

reticular layer

the deeper and thicker layer of the dermis; contains dense connective tissue, blood vessels, glands, nerves, and hair follicles

rule of nines

a method used to estimate the percentage of the body’s surface affected by a burn

sebaceous gland

an oil gland that usually attaches to a hair follicle and produces sebum

sebum

an oily substance that lubricates and waterproofs the skin and hair

slough

to shed or peel off dead cells or tissue

squamous cell carcinoma

a type of skin cancer that develops from abnormal squamous cells, usually in the epidermis

stratum basale (germinativum)

the deepest layer of the epidermis; contains dividing cells and melanocytes

stratum corneum

the outermost layer of the epidermis, made mostly of dead, keratin-filled cells

stratum granulosum

the epidermal layer where cells produce substances that help make the skin water-resistant and begin to die

stratum lucidum

a thin, clean layer found only in thick skin, such as the palms and soles

stratum spinosum

the epidermal layer above the straum basale; contains keratinocytes connected by strong desmosomes and provides strength

sudoriferous gland

sweat gland; includes eccrine and apocrine glands

sweat pore

an opening on the skin’s surface through which sweat is released

tactile (Meissner’s) corpuscle

a sensory receptor that detects light touch

tension line

a line showing the natural direction of tension in the skin; also called a cleavage line

thermoregulation

the body’s process of maintaining a stable internal temperature