Integumentary System Chan

8/6/2019 Integumentary System Chan

1/19


2/19

Integumentary Systemy Consists of the skin and accessory structures, such as hair,nails and glands.

y Integument means covering.Functions:

a. Protection1. Prevents water loss. Lipids act as barrier to the diffusion ofwater.2. Prevents entry of microorganisms and other foreignsubstances into the body.

3. Stratified squamus epithelium protects underlyingstructure against abrasion.4. Melanin absorbs UV.5. Hair acts as heat insulator.6. Nails protect the end of the digits from damage and can beused in defense.


3/19

b. Sensation sensory receptors that candetect heat, cold, touch, pressure and pain.

c. Vitamin D production when exposed toUV light, produces a molecule that can betransformed into Vit. D.

d. Temperature Regulation Regulated bycontrolling blood flow through the skin andthe activity of the sweat glands.

e. Excretion Small amounts of wasteproducts are lost throught the skin and ingland secretions.


4/19

Hypodermis attaches to theunderlying bone and muscle andsupplies it with blood vessels andnerves.

- also known as Subcutaneous Tissue.

- functions as padding and insulation.

- responsible for some of the differencesin appearance between men and

women.


5/19

y Dermis has fewer fat cells and blood vessels.

y

Nerve endings, hair follicles, smooth muscles,glands and lymphatic vessels extend into thedermis.

y Collagen and elastic fibers responsible for most

of the structural strength of the skin.y Striae/Stretch marks overstretched skin and

damaged dermis.

y Dermal Pappilae contains many blood vesselsthat:

y Supply nutrients

y Remove waste products

y

Aids in regulating body temperature


6/19

yEpidermis Stratified squamous

epithelium.yStratum Basale deepest stratum

y consists of cuboidal or columnar cells

y

Stratum Corneum

most superficialstratum of the epidermis.

y Dandruff- Excessive stratum corneum cellssloughed from the surface of the scalp.

y Callus skin is exposed to friction = increasedlayers in the stratum corneum = producing athickened area.

y Corn A cone-shaped structure over a bonyrominence.


7/19


8/19

Skin Colory Determined by:y Pigments in the skin

y Blood circulating

y

Thickness of the stratum corneumy Melanin group of pigments responsible for skin, hair, and

eye color.

y Most are brown to black pigments, some are yellowish or

reddish.y Provides protection against UV light from the sun.

y Produced by melanocytes

y Occurs in some regions of the skin: Freckles, moles, genitalia,

nipples and areola.


9/19

yProduction is predetermined by:

y Genetic factors

y Albinism recessive genetic trait that causes adeficiency or absence of melanin.

y Have fair skin, white hair and unpigmented irises

in the eyes.y Exposure to light Sunlight stimulates melanocytes

to increase melanin production.

y Hormones

ySkin Colors:

y Erythema

y Cyanosis

yJaundice


10/19

yCarotene yellow pigment in plantssuch as squash and carrots.

yLipid soluble, accumulates in the

lipids of the stratum corneum and inthe fat cells of the dermis and

hypodermis.yGives the skin a slight yellowish tint.


11/19


12/19

Hairy Produced in the hair bulb, which rests on a dermal

papilla.

yPartsy Shaft protrudes above the surface of the skin

y Root and Hair Bulb below the skin

y Cortex hard bark

y Medulla softer center surrounded by Cortex

y Cuticle covers the Cortex

y Extension of the epidermis deep into the dermis.

y Plays an important role in tissue repair.


13/19

MusclesyArrector Pili contraction causes

the hair to become moreperpendicular to the skins surface,or to stand on the end

yProduces a raised area of skin=goose flesh


14/19

y Major glands of the skin:y Sebaceous

y Produces sebum

y lubricates the hair and the surface of the skin

y Prevents drying and protects against some bacteria.

y Sweat Glands

y Merocrine

y coiled tubular glands located in almost every part of the

skin

y Most numerous in the palm and soles

y Have ducts that open onto the surface of the skin throughsweat pores.

y Produce sweat which evaporates and cools the body.

Glands


15/19

yApocrineySimple, coiled tubular glands that produce

a thick secretion rich in organic

substances.yOpen into hair follicles = axillae and

genitalia

yBecomes active at puberty because of theinfluence of sex hormones


16/19


17/19

Nailsy Is a thin plate, consisting of layers of dead stratum

cornum cells that contain a very hard type of keratin.

y Parts:

y

Nail body

visible part of the naily Nail Root part of the nail covered by the skin

y Eponchium/Cuticle a stratum corneum that extendsonto the nail body.

y Nail Bed where the nail root and nail body areattached.

y Lunula whitish, crescent-shaped area at the base ofthe nail.


18/19


19/19

Effects ofAging on the

Integumentary SystemyMore easily damaged

ySkin sags/Wrinkles

y Impaired thermoregulation

ySkin becomes drier

yDecrease number in melanocytes butincrease in some areas cause Age Spots

yGray/white hair

Integumentary System Chan

Documents

Transcript of Integumentary System Chan