Integumentary Systeggggggggggggfgvhhhhhhhhhhhhhm W-o Quiz

7/24/2019 Integumentary Systeggggggggggggfgvhhhhhhhhhhhhhm W-o Quiz

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Integumentary System

CMM News


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Functions Of The IntegumentCushionsand insulates deeper organs

Protectsbody from abrasion, trauma, chemicapathogens, temperature extremes and UV rays

Excretion and secretion

Contains sensory receptorsassociated with n

endingsSynthesis and storage of nutrients (vitamin D3)


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Integumen

System Largest bo

Skin Hair

Nails

Glands


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Integumentar

Epidermis

Outermost laye

the skin Dermis

Contains collag

Supports nervevascular netwo

Subcutaneous

Fat and loose

connective tiss


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Structure Epidermis: Thin avascular

superficial laye

Nourished bloovessels (dermi

Replaced ever

days

Types of cells:

Melanocyt

keratinocy


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Integumentary StructuresComponents of the Integumentary S


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Skin Structures


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The Epidermis- Four Main Cell Melanocytes - found in basal

layer, manufacture and secrete

pigment Merkel cells - basal layer,attached to sensory nerveendings

Keratinocytes Arise fromdeepest layer of epidermis to

stratum spinosum Produce keratin a toughfibrous protein

Produce antibodiesandenzymes

Keratinocytes are dead at skin'ssurface

Langerhans cells - stratum


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Stratified squamous epithelium

Several distinct cell layers

Thick skinfive layers on palms and soles

Thin skinfour layers on rest of body


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Layers of The Epidermis

Stratum corneum Most superficial layer

Dead, flattened(squamous) cells

Abundant keratin -Keratinized(cornified)tough, water-resistantprotein

Protects skin againstabrasion andpenetration

Stratum lucidum(clearlayer) Occurs only in thick skin

palms and soles

Composed of a few


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Layers of The Epidermis


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Layers of the Epidermis

Stratum basale

Deepest layer of epidermis Attached to underlying

dermis

Stem cells actively divide

Merkel cells associated

with sensory nerve ending Melanocytes secrete the

pigment melanin


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Epidermal Cells and Layers of the Epiderm


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Sources of Skin Color

Melanocytes Make melanin from tyrosine

Melanin provides UVprotection

Gives reddish-brown tobrown-black color

Carotene Contributes orange-yellow

color Provided from diet (carrots

and tomatoes)

Hemoglobin - bloodpigment Caucasian skin contains

little melanin


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Dermis

Richly supplied with nerves (sensory receptors), blood vessels, lymphatic vessels,

sebaceous glands derived from the epidermis. Contains two layers: papillary and

Papillary regionis composed of loose areolar connective tissue. This is n

fingerlike projections called papillae, that extend toward the epidermis and c

terminal networks of blood capillaries or tactile Meissner's corpuscles.

Reticular layeris the deep layer of the dermis and consists of the dense irre

tissue. Within the reticular region are the roots of the hair, sebaceous glands

receptors, nails, and blood vessels.


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Dermal Components


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Subcutaneous Layer - Hypodermis

Composed of loose connective tissue - areolar and adipose

Stabilizes skin position

Loosely attached to dermis

Loosely attached to muscle

Contains many fat cells

Provides thermal insulation

Cushions underlying organs

Safely receives hypodermicneedles


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Hair Filamentous strands of dead

keratinized cellsproduced by hairfollicles

Contains hard keratin which is tougherand more durable than soft keratin ofthe skin

Chief parts of a hair

Root imbedded in the skin

Shaft projects above skin's surface


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Hair Function and Distribution Functions of hair include:

Helping to maintain warmth

Alerting the body to presence of insects on the skin

Guarding the scalp against physical trauma, heat loss, and su

Hair is distributed over the entire skin surface except

Palms, soles, and lips

Nipples and portions of the external genitalia


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Glands

There are there exocrine (conts ducts) glands: sebaceous,

sudoriferous and;

These glands secrete their contents to the exterior unlike end

secrete their contents directly into blood.


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Sebaceous Glands (oil glands) Occur over entire body - Except palms and soles

Simple alveolar glands

Holocrine secretion entire cell breaks up to form secretion

Secretes an oily substance called sebum

Most are associated with a hair follicle

Functions of sebum

Softens and lubricates hair and skin

Skin waterproofing

Collects dirt


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Sudoriferous Glands (Sweat) Two types:

Eccrine (Merocrine) Most abundant sweat gland

True sweat

99% water with some salts

Contains traces of metabolic wastes ~ 2%

urea

Role in thermoregulation

Widely present in skin (up to 500/cm2)

Apocrine

Odorous secretion

Absent before puberty

Present in axillary, areolar, anal and genital

areas


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Ceruminous Gland

specialized sudoriferous glands

found only in the external auditory canal where they secrete

(earwax)

Cerumenis also an insect repellant and keeps the eardrum f

out.

However, an excess of this may cause blockage.


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Nails Scalelike modification of epidermis

made of hard keratin

Parts of the nail

Free edge

Body - dense mass of keratinizedcells

Root

Nail folds

Eponychium cuticle


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Skin Injury and Repair

Four Stages in Skin Healing1. Hemostasis

a. Blood flow increases

b. Phagocytes attracted

2. Inflammation

3. Proliferative Stage4. Remodeling


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Hemostasis

This process is the stoppage of bleeding


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Hemostasis

A special protein known as Fibrincross links on top of

which prevents blood from flowing out and pathogen

coming in


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Inflammation

Shows sign of redness and swelling

Phagocytosis

Vasodilation


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Inflammation: Phagocytosis

Occurs when the white blood cells known as Macroph

consume and destroy bacteria


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Inflammation: Vasodilation

Expansion of the blood vessels


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Proliferative Stage

Entry of Fibroblast Cells

Collagen Deposition


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Proliferative Stage: Collagen Deposition

The fibroblast cell release collagen which forms conne

tissue to replace fibrin

Dermis contacts to close the wound


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Remodeling

Collagen is then rearranged and converted to spe

Skin slowly return to its original state as best as it

Wound may then just end up as a scar


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Burns


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Effects of UV Radiation


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Types and Growth of Hair

Vellus hairs

Body hairs of women and children

Terminal hairs

Hair of scalp

Axillary and pubic area (at puberty)

Hair thinning and baldness Due to aging

Male pattern baldness


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Skin Cancer

Melanocytesare the

skin cells that have

clustered thus

forming a mole. They

are also melanin

producing cells


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Skin throughout life

Fetal skin

Well formed after the fourth month At 5-6 months the fetus is covered with lanugo (downy h

Fetal sebaceous glands produce vernix caseosa

Middle to old age

Skin thins and becomes less elastic

Shows harmful effects of environmental damage Skin inflammations become more common


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Integumentary Systeggggggggggggfgvhhhhhhhhhhhhhm W-o Quiz

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