The INTEGUMENTARY System

The INTEGUMENTARY SystemFunctions of the Integumentary SystemGuard the bodys physical and biochemical integrity

Maintain a constant body temperature

Provide sensory information about the surrounding environment.

Your SkinA large organ composed of all 4 tissue types (connective, epithelial, muscular, nervous) Has an area of about 22 square feet

Approximately 1-2 mm thick Weighs about 10 lbs

STRUCTURE OF THE SKINThe two major layers of the skin are:

Epidermis: the top portion of the skin; composed of epithelial tissue.Dermis: the deeper layer of the skin; primarily composed of connective tissue

Your epidermis.Is Avascular (contains no blood vessels)

Contains 4 types of cells: ~keratinocytes, ~melanocytes, ~Langerhans cells, ~Merkel cells

Has 5 distinct layers of cellsOverview of Epidermis

Dermis

Connective tissue layer

Contains hair follicles, glands, nerves & blood vesselsTattoosTattooing is a permanent coloration of the skin in which a foreign pigment is injected into the dermis.

Skin Color PigmentsThe wide variety of colors in skin is due to three pigments -melanin, carotene, and hemoglobin (in blood in capillaries) -in the dermis.

Accessory Structures of SkinHair

Oil & Sweat glands

Nails

HAIRHairsalso known as pili, are present on most skin surfaces:except the palms, palmar surfaces of the digits the soles, and plantar surfaces of the digits.

HAIRHair consists of a shaft above the surface a root that penetrates the dermis and subcutaneous layer the cuticle a hair follicle

HAIRStructure of Hair

Shaft -- visible

Root -- below the surface

Follicle-- surrounds root

HAIRArrector piliIs the smooth muscle in the dermis that contracts with cold or fear.Forms goose bumps as thehair is pulled vertically

HAIR Hair GrowthThe hair growth cycle consists of a growing stage and a resting stage.

Growth stage lasts for 2 to 6 years

Resting stage lasts for 3 months

Old hair falls out as growth stage begins again. Normal hair loss is 70 to 100 hairs per day!

Stages of HAIR GROWTH

Hair ColorHair color is due primarily to the amount and type ofmelanin.

Graying of hair occurs because of a progressive decline intyrosinase.

Hair ColorDark hair contains true melaninBlond and red hair contain melanin with iron and sulfur addedGraying hair is result of decline in melanin productionWhite hair has air bubbles in the medullary shaft

Hormones influence the growth and loss of hair.Functions of HAIRPrevents heat loss

Decreases sunburn

Eyelashes help protect eyes

Touch receptors (senses light touch)

NAILSNails protect the tips of your fingers and toes so that they can remain soft and sensitive

Nails form from nail roots under the skin at the base and sides of nails

As new cells form, the nail grows longer

NAILS Fingernails and toenails are made of a tough protein called keratin, as are animals' hooves and horns.

NAILSThe nail consists of the nail plate, the nail matrix and the nail bed below it, and the grooves surrounding

A. Nail plate; B. lunula; C. root; D. sinus; E. matrix; F. nail bed; G. hyponychium; H. free margin Where does nail growth occur?The nail grows from a deep groove in the dermis of the skin. All nail growth occurs at the nails base, where the specialized cells that make up the nails plate are produced; these cells are pushed forward as new cells form behind them

NAIL GROWTHIn humans, nails grow at an average rate of 3 mm (0.12 in) a month. Fingernails require three to six months to regrow completely, and toenails require 12 to 18 months. Actual growth rate is dependent upon age, sex, season, exercise level, diet, and hereditary factors. Nails grow faster in the summer than in any other season.

Disorders of the NAILSONYCHOPHAGY

Bitten nails, often no free edge is visible. Nails look ragged and distorted, skin and nail bed can be exposed and raw.

Why do fingernails turn blue?When a person's hands are cool, it is possible for these blood vessels to constrict, causing the nails to become more pale or even take on a bluish hue. Not enough oxygen delivery through the blood it is also possible reason

Disorders of the NAILS Pseudomonasbacterial infection occur between the natural nail plate and the nail bed, and/or between an artificial nail coating and the natural nail platefeeds off the dead tissue and bacteria in the nail platemay also cause the nail plate to lift from the nail bed.

26 Disorders of the NAILSFungal or Yeast infection This type of infection is characterized by onycholysis (nail plate separation) Appears white or yellowish in color, and may also change the texture and shape of the nail.The fungus digests the keratin protein of which the nail plate is comprised.

Disorders of the NAILSTinea UnguiumRingworm of the nail (dermatophyte)

Can be scraped off from the nail plate

Spreads to the nail root

Highly contagious

Wacky Facts About Your Nails1.Nails and hair do not keep on growing after death contrary to what is often stated as fact. The truth is that the body dehydrates after death, resulting in an appearance of hair and nails that seem to grow.2.Finger nails grow faster than toe nails. Finger nails grow at the approximate rate of a half an inch every 100 days. If you bite your nails down to the flesh it takes at least a month to re-grow!3.Nails on longer fingers grow faster than nails on short fingers. Nails also grow faster on your dominant hand. So if you must bite your nails, concentrate on the middle finger of your right hand if you are right handed.4.Massaging your finger tips will stimulate nail growth. So does typing on a keyboard.5.Nails grow much faster during pregnancy Wacky Facts About Your Nails6.Dry nails are mostly the result of not drinking enough. Unfortunately only water helps.7.A mans nails grow faster than a womans. This does not make a man superior.8.Nails grow faster in warm sunny climates than in cold dark places. If you must bite your nails, move to Southern California.

9.The older you are, the slower your nails grow.10.People biting nails do this out of habit. There is no medical cure. The only way to stop nail biting is to break the habit!

Oil & Sweat GlandsSweat glands are known mostly to help regulate temperature by bringing warm moisture to the surface of the skin, which causes cooling as the water evaporates. Also as a detoxifier-rids the body of certain wastes

Sweat Sweat GlandsThey are simple tubular glands found in almost every part of the skin

There are two to four million sweat glands distributed all over our bodies

Sweating is controlled from a center in the hypothalamus

Stimulated in response to; 1-high temperature 2-exercise 3- hormones 4-emotional stress

Stress Sweating vs Temperature Induced Sweatingemotionally induced sweating is restricted to palms ,soles , armpits and forehead

temperature induced sweating causes sweating throughout the body

Sweat & Its FunctionSweat is the watery fluid produced and excreted by the sweat gland Thermoregulation: primary function, allows the body to rid itself of excessive heat productionForms part of the hydrolipid film which is the protective covering keeping the skin in good condition plays a minor excretory role (some drugs and toxins are excreted in sweat)

Eccrine Apocrine

Types Of Sweat GlandsEccrineEccrine sweat is composed mainly of water and small amounts of solutes

Found virtually in all skin

ApocrineApocrine sweat consists mainly of mucin which explains its viscosity and large amounts of protein and steroids.Found in the the axillae (armpits), areola and nipples of the breast, ear canal & eyelids

Sebaceous (Oil) GlandsSecrete oil or sebumFound everywhere except palms, solesUsually secretes into hair follicleLubricates hair and skinSoftens dead cellspliabilitySlows water lossBactericidalStimulated by hormones

Ceruminous glandsThis are modified (eccrine) sweat glands in the passageway of the external ear. Their secretions combine w/ sebaceous glands forming CERUMEN.or earwax. Together w/ tiny hairs traps foreign particles.