Copyright © 2010 Pearson Education, Inc. INTEGUMENTARY SYSTEM What is the function of the integumentary system?

Copyright © 2010 Pearson Education, Inc. Incredible Human Machine: Skin Write down 3 interesting facts, be prepared to share your responses with the rest of the class. v=fXIcwm1oqQw

Copyright © 2010 Pearson Education, Inc. Integumentary System Major parts: 1.Cutaneous membrane (skin) epidermis (epithelium) dermis (CT) subcutaneous layer (hypodermis) –loose CT, attaches integument to structures 2. Accessory Structures – hair, nails, exocrine glands Anchored in dermis & extend up thru epidermis

Copyright © 2010 Pearson Education, Inc. Integumentary System 6 major functions: 1.Protects & prevents H 2 0 loss 2.Temp. maintenance (insulation & evaporation) 3.Synthesizes vitamin D 3 4.Storage (adipose tissue) 5.Sensory reception 6.Excretion & secretion of salts, water, wastes by glands

Copyright © 2010 Pearson Education, Inc. Figure 5-1

Copyright © 2010 Pearson Education, Inc. BR: Write down the following words. Subcutaneous fat Epidermis Dermis Melanin Oil glands Sebum Pores Hair Erector Pili Pilometer reflex Sweat glands

Copyright © 2010 Pearson Education, Inc. Epidermis Stratified squamous epithelium –nutrients & O 2 diffuse from capillaries in dermis Thin Skin - 4 layers (strata) Thick Skin - 5 layers –Palms & soles of feet

Copyright © 2010 Pearson Education, Inc. Epidermis 5 strata: (CELL LAYERS) 1.Stratum germinativum 2.Stratum spinosum 3.Stratum granulosum 4.Stratum lucidum 5.Stratum corneum

Copyright © 2010 Pearson Education, Inc. Stratum corneum Stratum granulosum Stratum lucidum Stratum spinosum Dermis Epidermal Ridge Dermal papillae Stratum germinativum

Copyright © 2010 Pearson Education, Inc. Epidermis 1.Stratum germinativum –contains germinative (stem) cells & melanocytes –forms epidermal ridges (extend into dermis) & dermal papillae (extend toward surface) ↑ SA for diffusion 2. Stratum Spinosum –cells may continue to divide

Copyright © 2010 Pearson Education, Inc. Epidermis 3. Stratum Granulosum –cells produce keratin – durable, H 2 O-resistant protein forms hair, nails, calluses 4. Stratum Lucidum (ONLY in thick skin) –thin cells filled w/ keratin

Copyright © 2010 Pearson Education, Inc. Epidermis 5. Stratum corneum –15-30 layers of dead keratinized cells –shed & replaced every 2 weeks –dry, oily surface inhibits microbial growth

Copyright © 2010 Pearson Education, Inc. BR Turn in Bell Ringers & Epidermis Chart

Copyright © 2010 Pearson Education, Inc. Skin Color Carotene (orange-yellow) –converted to vitamin A Melanin (yellow-brown or black) –stored in melanosomes –produced by melanocytes protects skin by absorbing UV radiation –causes DNA mutations & burns –skin color depends on amount of melanin production

Copyright © 2010 Pearson Education, Inc. Figure 5-3

Copyright © 2010 Pearson Education, Inc. Skin Color Blood vessels dilate from heat  skin reddens Blood flow to surface ↓’s  skin pales Cyanosis: bluish skin tint –caused by severe ↓ in blood flow or oxygenation

Copyright © 2010 Pearson Education, Inc. Effects of Sunlight Vitamin D 3 –produced by epidermal cells –liver & kidneys convert vitamin D 3 into calcitriol aids absorption of Calcium –insufficient vitamin D 3 can cause rickets (abnormally weak, flexible bones)

Copyright © 2010 Pearson Education, Inc. Effects of Sunlight Skin Cancers a.Basal cell carcinoma – most common –originates in stratum germ. b.Squamous cell carcinoma –superficial layers of epidermis c.Malignant melanoma – more dangerous –cancerous melanocytes metastasize thru lymphoid system

Copyright © 2010 Pearson Education, Inc.

The Dermis 1.Papillary Layer Loose CT 2. Reticular Layer dense irregular CT Collagen & elastin Both contain blood & lymph vessels, nerve fibers.

Copyright © 2010 Pearson Education, Inc. Hypodermis: Subcutaneous –Allows independent movement –Shock absorption & E storage –has few capillaries & no vital organs  site of subcutaneous injections

Copyright © 2010 Pearson Education, Inc. Hair Fxns: –protects & insulates –Guards against foreign particles –Sensitive to very light touch (warning system)

Copyright © 2010 Pearson Education, Inc. Figure 5-5 papilla: CT containing capillaries & nerves –stem cells surrounding hair papilla form hair root: anchors hair into skin shaft: part of hair on surface arrector pili muscle: causes goose bumps

Copyright © 2010 Pearson Education, Inc. Hair Follicles Figure 5-5

Copyright © 2010 Pearson Education, Inc. Exocrine Glands 1.Sebaceous (Oil) Glands (holocrine) –discharge sebum into hair follicles or directly onto skin Lubricates and inhibits bacterial growth Cause Acne

Copyright © 2010 Pearson Education, Inc. Exocrine Glands 2.Sweat Glands Apocrine secrete products into hair follicles sticky, cloudy secretion can cause odors Armpits, groin, & around nipples Merocrine (Eccrine) discharge directly onto skin, cool the body H 2 0 (99%), electrolytes, organic nutrients, waste products (urea), dermicidin (antibiotic) flush microorganisms & chemicals from skin

Copyright © 2010 Pearson Education, Inc. Figure 5-7

Copyright © 2010 Pearson Education, Inc. Nails Nail body consists of dead, keratinized cells nail growth occurs at nail root (epidermal fold below surface) Figure 5-8

Copyright © 2010 Pearson Education, Inc. Repair Figure 5-9

Copyright © 2010 Pearson Education, Inc. Repair Figure 5-9

Copyright © 2010 Pearson Education, Inc. Repair of Skin Injuries

Copyright © 2010 Pearson Education, Inc. Effects of Aging epidermis thins  skin injuries & infections more common dermis thins  sagging & wrinkling of skin vitamin D 3 production ↓’s  weaker muscles & bones melanin production ↓’s gland activity ↓’s  skin becomes dry & scaly hair thins & loses color blood supply to skin ↓’s, sweat glands less active  ability to release heat ↓’s skin repairs more slowly

The Integumentary System in Perspective Functional Relationships Between the Integumentary System and Other Systems Copyright © 2010 Pearson Education, Inc.

The Skeletal System  provides structural support The Integumentary System synthesizes vitamin D 3, essential for calcium and phosphorus absorption (bone maintenance and growth) The Skeletal System Copyright © 2010 Pearson Education, Inc.

The Muscular System The Muscular System’s facial muscles pull against skin of face, producing expressions important in communication The Integumentary System synthesizes vitamin D 3, essential for normal calcium absorption (calcium ions play an essential role in muscle contraction) Copyright © 2010 Pearson Education, Inc.

The Nervous System The Nervous System controls blood flow and sweat gland activity for thermoregulation; stimulates contraction of arrector pili muscles to elevate hairs The Intergumentary System’s receptors in dermis and deep epidermis provide sensations of touch, pressure, vibration, temperature, and pain Copyright © 2010 Pearson Education, Inc.

The Endocrine System The Endocrine System includes the sex hormones that stimulate sebaceous and apocrine gland activity, and develop secondary sexual characteristics; suprarenal hormones alter blood flow to skin and mobilize lipids from fat cells The Integumentary System synthesizes vitamin D 3, precursor of calcitriol, a hormone produced by the kidneys Copyright © 2010 Pearson Education, Inc.

The Cardiovascular System The Cardiovascular System provides oxygen and nutrients; delivers hormones and cells of immune system; carries away carbon dioxide, waste products, and toxins; provides heat to maintain normal skin temperature The Integumentary System’s mast cells produce localized changes in blood flow and capillary permeability Copyright © 2010 Pearson Education, Inc.

The Lymphatic System The Lymphoid System assists in defending the integument by providing additional macrophages and mobilizing lymphocytes The Integumentary System provides physical barriers that prevent pathogen entry; macrophages resist infection; mast cells trigger inflammation and initiate the immune reponse Copyright © 2010 Pearson Education, Inc.

The Respiratory System The Respiratory System provides oxygen and eliminates carbon dioxide The Integumentary System’s hairs guard entrance to nasal cavity Copyright © 2010 Pearson Education, Inc.

The Digestive System The Digestive System Provides nutrients for all cells and lipids for storage by adipocytes The Integumentary System synthesizes vitamin D 3, needed for absorption of calcium and phosphorus Copyright © 2010 Pearson Education, Inc.

The Urinary System The Urinary System excretes waste products, maintains normal body fluid pH and ion composition The Integumentary System assists in elimination of water and solutes; keratinized epidermis limits fluid loss through skin Copyright © 2010 Pearson Education, Inc.

The Reproductive System The Reproductive System’s sex hormones affect hair distribution, adipose tissue distribution in subcutaneous layer, and mammary gland development The Integumentary System covers external genitalia; provides sensations that stimulate sexual behaviors; mammary gland secretions provide nourishment for newborn infant Copyright © 2010 Pearson Education, Inc.