the integumentary system. skin, hair and nails now using the microscopes. examine your skin, hair...

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The Skin

The Integumentary System

Skin, Hair and Nails Now using the microscopes. Examine your skin, hair and nails.In your spiral, diagram what you see.

Organs of the integumentary systemskinhairnails

The name is derived from the Latin integumentum, which means a covering. Label and color the parts of the integumentary system

finger nailSkinThe largest organ in your bodyFunctionsCovers the body and prevents water lossProtects the body from injury and infectionRegulates body temperatureEliminates wastes (sweat)Produces vitamin DGathers information about the environmentStores fat for fuel and insulationPrevents Water LossSkin prevents water from leaking out of your body

Prevents InfectionSkins acts as a barrier to bacteria and viruses

Maintains HomeostasisHelps to keep the body temperature normalHas blood vessels that tell the body when it is hot or coldHot blood vessels get larger and sweating occursCold blood vessels constrict to keep blood in the bodys coreEliminates WasteSweating eliminates dissolved waste from your body

Gathers InformationSkin contains nerves that can feel pain or pressure

Provide Vitamin DWith the help of sunlight, your skin produces vitamin DVitamin D is essential in calcium absorption from food

Layers of SkinSkin consists of three main layersepidermisdermissubcutaneous layer

subcutaneous layerEpidermisOutermost layer30-60 cells thickNo nerves or blood vesselsTop layer is deadNew cells formed at the bottom of this layerSkin cells shed every 2 weeksWhere nails growContains melaninEpidermisWhere nails growContains melaninEvery minute, 30,000 - 40,000 skin cells fall off95% of your skin cells make new cells5% make melaninMore sun exposure = more melanin (tan)

DermisMiddle layerContains nerves and blood vesselsContains sweat glands, oil glands and hair folliclesContains collagen and elastin that allows skin to stretch

subcutaneous layerMade mostly of fatKeeps you warmAbsorbs shockAttaches your skin to the underlying tissue

hairMade of a strong, dead protein, called keratinGrows out of a tiny tube called a follicleHair growth is caused by rapid mitosis in the follicleHair follicles are everywhere exceptlipspalmssoleshairOver 100,000 follicles on the scalpEach follicle is attached to a gland that secretes sebum (oil)Color is partially determined by melanin

nailsModified hair that grows from your cuticleMade of keratinNo nerve endingsProtects the end of fingers and toesTakes 6 months to grow from cuticle to tip

nailsFingernails grow faster than toenailsNails grow faster on your dominant handNails DO NOT grow after death

Body systems that work with the integumentary system;respiratory system to get oxygen and remove carbon dioxidecirculatory system to deliver oxygenexcretory system to eliminate waste