Chapter 5 The Integumentary System

Integumentary System

The skin, hair, nails, and glands that protect the body

Skin Functions

Protection, sensation, thermoregulation, excretion, and vitamin D production

Epidermis

Outer layer of skin made of epithelial tissue

Dermis

Inner layer of skin containing blood vessels, nerves, glands, and hair follicles

Hypodermis

Layer below the skin containing fat tissue for insulation and cushioning

Protection

Skin function that protects against injury, germs, water loss, and UV rays

Sensation

Skin function that allows the body to feel touch, pain, pressure, and temperature

Thermoregulation

Control of body temperature

Excretion

Removal of wastes through sweat

Vitamin D Production

Skin helps produce vitamin D when exposed to sunlight

Stratum Corneum

Outermost epidermis layer made of dead keratinized cells

Stratum Lucidum

Clear epidermis layer found only in thick skin

Stratum Granulosum

Epidermis layer where keratin production increases

Stratum Spinosum

Epidermis layer containing many living skin cells

Stratum Basale

Deepest epidermis layer where new skin cells are produced

Melanocyte

Cell that produces melanin

Melanin

Pigment that gives skin and hair color

Merkel Cell

Touch receptor cell in the epidermis

Langerhans Cell

Immune cell that helps protect against pathogens

Thick Skin

Skin found on palms and soles that contains all five epidermal layers

Thin Skin

Skin found on most of the body that lacks the stratum lucidum

Callus

Thickened area of skin caused by friction or pressure

Papillary Layer

Upper dermis layer made of loose connective tissue

Dermal Papillae

Structures that form fingerprints and nourish the epidermis

Reticular Layer

Deep dermis layer made of dense irregular connective tissue

Blister

Fluid-filled pocket formed when epidermis separates from dermis

Hair

Structure that protects the body, provides sensation, and helps reduce heat loss

Hair Follicle

Structure in the dermis where hair grows

Arrector Pili Muscle

Small muscle attached to hair follicles that causes goosebumps

Goosebumps

Raised hairs caused by contraction of arrector pili muscles

Nail

Keratinized structure that protects fingertips and toes

Keratin

Strong protein found in skin, hair, and nails

Nail Body

Visible part of the nail

Nail Root

Hidden portion of the nail beneath the skin

Nail Matrix

Region where nail growth occurs

Lunula

White half-moon shape at the base of the nail

Eponychium

Cuticle around the base of the nail

Eccrine Sweat Gland

Sweat gland that produces watery sweat for cooling

Apocrine Sweat Gland

Sweat gland found in armpits and groin that produces thicker secretions

Ceruminous Gland

Gland that produces earwax

Mammary Gland

Gland that produces milk

Sebaceous Gland

Oil gland associated with hair follicles

Sebum

Oily secretion that lubricates and protects skin and hair

Cellulite

Dimpled appearance of skin caused by fat beneath the skin

Basal Cell Carcinoma

Most common skin cancer that begins in the stratum basale

Squamous Cell Carcinoma

Skin cancer that begins in the stratum spinosum

Malignant Melanoma

Most dangerous skin cancer that develops from melanocytes

ABCDE Rule

Method for identifying possible melanoma

A in ABCDE Rule

Asymmetry

B in ABCDE Rule

Border irregularity

C in ABCDE Rule

Color variation

D in ABCDE Rule

Diameter greater than 6 mm

E in ABCDE Rule

Evolving or changing appearance

Blood Vessels in Skin

Located in the dermis, not the epidermis

Function of Sweat

Helps cool the body and remove wastes

Function of Sebum

Waterproofs and protects skin and hair

Function of Dermal Papillae

Increase blood supply and form fingerprints

Function of Melanin

Protects skin from UV radiation

Function of Hair

Protection, sensation, and heat retention

Function of Nails

Protection and assistance with grasping objects