Define identify key terms Discuss the structure and function of the skin, hair, nails and mucous membranes Discuss the functions of the three major.

Define identify key termsDiscuss the structure and function of the skin, hair, nails and mucous membranes

Discuss the functions of the three major glands located in the skin

State the effects of aging on the integumentary system

The integumentary system is the largest and most visible system in the body.

Maintenance of this system is important to both physiological and psychological well-being

The integumentary system includes:

SkinHairScalpNailsMucous membranes

The skin is the largest organ of the body. It covers the entire outside of the body. Its main functions are homeostasis and protection of the internal organs.

It is the first line of defense against infection and injury.

It is pliable, yet tough, It insulates and cushions deeper organs.

It prevents loss of body fluids and regulates body temperature.

It is the body’s sensory contact with the environment because it is sensitive to heat, cold , touch, pressure and pain.

Vitamin D synthesis. See Box 3-1 in your Adult Health Nursing

book.

Protection Temperature regulation Vitamin D synthesis Maintains fluid and electrolyte balance Screens out Ultraviolet Radiation Serves as a sensory organ Temporarily stores fat, glucose, water and

salts Absorbs certain drugs and chemical

substances

Sensory receptors within the skin receive information about the environment. Messages about heat, cold, pressure and touch are received and relayed to the central nervous system for interpretation.

Healthy skin absorbs many chemicals and foreign substances. As long as it remains intact, it provides protection from many microorganisms.

The internal organs are cushioned by a subcutaneous layer of adipose (fat) tissue.

The skin aids in the elimination of waste products, prevents dehydration and serves as a reservoir for food and water.

It does this by allowing blood vessels near the surface to constrict when the environment is cold to preserve heat, and allowing them to dilate when it is too hot to release excess heat.

Sweat glands release moisture, which results in cooling as the moisture evaporates.

A layer of adipose tissue works as an insulator by retaining heat.

Hyperthermia -Core body temperature 106 F -Sweating stops, skin becomes flushed and dry -Causes confusion and eventually coma and death Hypothermia -Core body temperature drops below 95 F -Causes confusion, disorientation -Leads to coma and death

COLD HEAT

Cholesterol compounds located in the skin are converted to Vitamin D when exposed to the ultraviolet rays of the sun.

Two layers of the skin:

◦Epidermis

◦Dermis

EPIDERMIS: -the superficial layer

-avascular -outer, dead, cornified portion, and a deep, living cellular portion -made up of stratified squamous epithelium - layers are called strata.

-cells are tightly packed -have no distinct blood supply Inner layer-stratum germinativum -only layer that can undergo cell

- division and reproduce itself -receives its blood supply and nutrition from the dermis - process called diffusion

-The process of diffusion -a constant new supply of cells to the upper layers. -this allows the skin to repair itself from injury. -When these cells are pushed to the surface, they undergo changes. -When they reach the outermost layer (stratum corneum), they are flat

and are filled with a protein called keratin

(horn).

Keratin -makes the cells dry, tough, and somewhat waterproof Melanocytes -specialized cells which give rise to the pigment called melanin. Melanin -a black or dark brown color that occurs naturally in the hair, skin, iris, and choroid of the eye -the greater the concentration of

melanin, the darker the skin.

-outermost covering of epithelial cells with no blood vessels

-the outer layer of the skin

-no blood supply – cells are packed tightly

-divided into strata or layers

The amount of melanin that one has, is inherited from the parents.

Even though the skin color is inherited, exposure to the sun can darken the skin.

-well supplied with blood vessels, nerves, sweat glands, and hair follicles. -varies in thickness throughout the body -thickest in the palms of the hands and the

soles of the feet. -connective tissue with cells scattered among collagen and elastic fibers

-collagen gives strength. -elastic connective fibers give it flexibility. -cells in this layer are bathed in interstitial fluid -with the normal aging process, these cells in the dermis lose some elastic connective fibers.

Papillae -upper portion -finger-like projections -project into the epidermal layer

-also called the superficial fascia -layer directly under the dermis -connects the skin to the muscle surface -layer is composed of adipose tissue and loose connective tissue

FUNCTIONS -Stores water and fat. -Insulates the body. -Protects the organs lying beneath it. -Provides a pathway for nerves and blood vessels. -Gives the body its shape and contour.

SUDORIFEROUS GLANDS -sweat glands - coiled tubelike structures in the dermis and subcutaneous layers. -open into pores on the skin surface. -excrete sweat which cools the body’s surface.

-Sweat -composed of water, salts, uric acid, ammonia, sugar, lactic acid, and ascorbic acid

-modified sudoriferous glands. -secrete a waxlike substance called cerumen. -located in the external ear canal. -protects the canal from foreign body invasion.

-oil glands -secrete sebum (an oily substance) through the hair follicles distributed in the body. -lubricates the skin and hair that covers the body. -inhibits bacterial growth.

-Hair - is composed of dead epidermal tissue, mainly keratin. -distributed all over the body in varying amounts. -hair follicle (root) is in the dermis. -hair shaft protrudes from the skin.

-a band of muscle tissue (called arrector pili) surrounds the follicle. -these muscles contract when they sense fear or cold. -hair stands upright and the skin dimples around it. -gooseflesh/goosebumps (piloerection)

-composed of keratin -closely compressed -base (root) of the nail is composed of living cells, and is covered by the cuticle. -part of the root (lunula) is exposed. It looks like a crescent moon. -nail body -appears pink because of the blood vessels lying beneath it.

-composed of a thin layer of epithelial cells -an underlying layer of connective tissue for strength -secrete mucus, -a thick, slippery material which keeps the membranes moist and soft and protects against bacterial invasion. -line body surfaces that open to the outside environment.

-nose, mouth, gastrointestinal, and reproductive tracts. -acts as a lubricant for food as it moves along the digestive tract. -respiratory tract, it acts as a sticky trap for contaminants.

-Adult -20% of the skins thickness is reduced -blood flow is reduced Elderly clients (over 65 years old) -skin breaks down more easily and quickly from prolonged pressure -immobile clients should be turned every 2 hours and if ill, may need turned more frequently to prevent skin breakdown

-skin becomes thinner and easily injured -subcutaneous tissue loss causes sagging and wrinkling -decreased activity of sebaceous and

sweat glands -age spots and gray hair occur

Reduced vascularity Diminished inflammatory response Hyperthermia Hypothermia Diminished pain perception Thinning epidermis Delayed wound healing