The Integumentary System By: Me and Luciano

What is it? Nail Skin Hair 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 Nail Skin Hair

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 Pictures Part 2 Dermatitis Melanoma Nickel Allergy Warts 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 Epidermis Thick 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) Classification-Simple coiled tubular Secretory Units-Shape like tubules Ducts-Unbranched Found through out the body Most common in forehead Begin functioning at birth A: Common sweat gland (duct) B: Myoepithelial cell C: Common sweat gland (secretory unit)

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 D: Cortex E: Medulla 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

Luciano’s 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