The Integumentary System

By: Me and Luciano

What is it?

• It is the system composed of hair, skin and nails.

• A system is an association of two or more organs that work together to do something

Hair Skin Nail

Skin• Largest organ of the body• 2 layers: dermis (lower)

and epidermis (upper)• SA of 1 to 2 meters• 16% of body weight A: common sweat gland

B: hair follicle

C: arrector pili

D: sebaceous gland

E: hair shaft

F: epidermis

G: dermis – pars papillaris

H: dermis – pars reticularis

I: hypodermis

Skin Parts• Arrector Pili – Erects hair during cold or emotional stress

• Sebaceous Gland – Oil gland; Keeps skin from drying out

• Epidermis – Upper layer of skin; Protects dermis and rest of body

• Dermis – Below epidermis; Contains nerve-endings, sweat and subaceous glands, and blood and lymph vessels

• Hypodermis – Independent fat cells below dermis

A: common sweat gland

B: hair follicle

C: arrector pili

D: sebaceous gland

E: hair shaft

F: epidermis

G: dermis – pars papillaris

H: dermis – pars reticularis

I: hypodermis

Skin Functions in Homeostasis

• Protection

• Body temperature regulation

• Sensory reception

• Water balance

• Syntheses of vitamins and hormones

• Absorption of materials

Common Skin Pathology• Apocrine glands produce a solution that bacteria act upon to

produce body odor• If the sebaceous glands become plugged and infected, it

becomes a blemish or pimple• Cancer: carcinoma and melanoma• Contact dermatitis (e.g. poison ivy)• Burns – First, second and third degree• Wrinkles • Calluses• Moles• Psoriasis• Hair loss• Frostbite

Common Pathology PicturesPart 2 Melanoma

Warts

Dermatitis

Nickel Allergy

Kaposi’s Saracoma

Wrinkles

• Major difference between young and old

• Loss of elasticity

• More common in light-skinned people

• Cross-linking collagen fibers

Thick vs. Thin

Thin Skin = Thin EpidermisThick vs. Thin Part II

• Epidermis of thick skin is 10x epidermis of thin.

• The different is in the thickness of the st. corneum

• Thickest skin on body is the thin skin on the back

Miscellaneous Skin Info

• Epidermis replaces itself every 15-30 days

Sweat Glands(Common)

A: Common sweat gland (duct)

B: Myoepithelial cell

C: Common sweat gland (secretory unit)

•Classification-Simple coiled tubular

•Secretory Units-Shape like tubules

•Ducts-Unbranched

•Found through out the body

•Most common in forehead

•Begin functioning at birth

Sweat Gland ‘apocrine’(Large)

• Classification-Simple coiled tubular

• Secretory Units-Shape like tubules

• Ducts-Unbranched• Secretory units much larger than in

common glands

Skin Color (pigment)

• Melanin (yellow-brown-black)

• Carotene (yellow- orange)

- accumulates in corneum

• Hemoglobin (red)

• Erythema vs. Cyanosis

-Influenced by blood flow, liver (jaundice)

Hair

• Derived from skin

• Extends above the skin surface

• Made of Keratin

D: Cortex

E: Medulla

Hair follicle

Hair Diseases

• Baldness –Loss of hair

• Hair thinning – thinning of hair

• Hair graying –graying of hair

Nails

• Highly Keratinized, modified epidermal cells

• Arises from nail bed.

• Rate of growth depends on finger length

Nail Diagram

Nail Pathology

• Nail Fungus

• Ingrown nail

Bibliography

Jason’s Bibliography• Body Systems• The Human Body (its structure

and operation)• http://www.exn.ca/human/home

.cfm• http://www.dermnet.org.nz• http://www.kidinfo.com/

health/Human_Body.html• http://www.dictionary.com• http://

www.medicaldictionary.com/

Luciano’s Bibliography

• How the Body works

• The Human Body

• http://gened.emc.maricopa.edu/bio/bio181/BIOBK/BioBookINTEGUSYS.html

• http://www.med.sc.edu/hightower/askinnoBG/sld001.htm

• http://www.anatomy.gatech.edu/aging/skin/tsld001.htm