INTEGUMENTARY SYSTEM SKIN& BODY MEMBRANES

MEMBRANES Structure: Thin, sheet like structureStructure: Thin, sheet like structure Functions:Functions: –Cover and protect the body surface –Line the body cavities –Cover the inner surface of the hollow organs (digestive, reproductive, respiratory) –Anchor organs to each other or to bones –Cover internal organs –Secrete lubricating fluids that reduce friction during organ movements

Two Types of Body Membranes Epithelial MembranesEpithelial Membranes –Cutaneous membrane (skin) –Serous membranes (protection/reduce friction for organs) –Mucous membrane (line body surfaces opening directly to the exterior– such as the esophagus; mucus secretion) Connective Tissue Membrane (no epithelium)Connective Tissue Membrane (no epithelium) –Smooth & slick, secrete synovial fluid –Reduce friction b/w opposing bones, line bursa sacs

SEROUS MEMBRANES Two Layers:Two Layers: –Visceral: covers the surface of the organ –Parietal: lines the walls of the body cavity Thoracic Cavity=PleuraThoracic Cavity=Pleura Abdominal Cavity=PeritoneumAbdominal Cavity=Peritoneum –Describe the following: Visceral pleura, parietal pleuraVisceral pleura, parietal pleura Visceral peritoneum, parietal peritoneumVisceral peritoneum, parietal peritoneum –What is pleurisy? What is peritonitis?

SKIN FUNCTIONSFUNCTIONS –Protection against microbes, UV rays, harmful chemicals, cuts & tears –Temperature regulations –Sense organ activity: touch, pressure, pain, temperature –Metabolic functions: synthesis of vitamin D

Skin: Structure Two Layers:Two Layers: –Epidermis outermost & thinnestoutermost & thinnest cells are very tightly packedcells are very tightly packed –Dermis deep & thickdeep & thick primarily connective tissueprimarily connective tissue loosely packedloosely packed Hypodermis (adipose tissue)Hypodermis (adipose tissue) –Deep to the skin/dermis –Layer of insulation

Epidermis Stratum corneumStratum corneum –Dry, dead, keratin filled cells Statum germinativum/basaleStatum germinativum/basale –Cells undergoing mitosis, move up

Epidermis Specialized cells within epidermis:Specialized cells within epidermis: –Melanocytes Melanin: pigment, inc. w/sun (protection)Melanin: pigment, inc. w/sun (protection) –Keratinocytes Keratin: tough, waterproof material; abrasion resistance for cellsKeratin: tough, waterproof material; abrasion resistance for cells –Langerhans cells Immune response against microbes invading the skinImmune response against microbes invading the skin

Dermis Collagen, elastin fibers– scatteredCollagen, elastin fibers– scattered

Dermal-epidermal junction Dermal papillae: parallel rows of peg-like projectionsDermal papillae: parallel rows of peg-like projections –Unique to each individual=Fingerprints

Dermis Specialized structures:Specialized structures: –Hair follicle: cells of the epidermis extend into the dermis forming a small tube –Hair bulb: base of the follicle –Hair papilla: cluster of cells (live); nourished by BV’s –Root: part of hair hidden in follicle –Shaft: visible part of hair

Dermis Specialized Structures (continued)Specialized Structures (continued) –Arrector pili: tiny, smooth muscle attached to base of dermal papillae & side of hair follicel Contracts: pulls on both simultaneously>>goosebumpsContracts: pulls on both simultaneously>>goosebumps

Specialized Structures of the Dermis Sebaceous GlandsSebaceous Glands –Secrete oil (sebum) for hair/skin –Ducts open into hair follicles –Accumulated sebum enlarges ducts>>white heads –Darkened sebum>>black head

Specialized Structures of Dermis Sudoriferous GlandsSudoriferous Glands –Eccrine Glands WidespreadWidespread Watery FluidWatery Fluid –Apocrine Glands Armpits/GenitalsArmpits/Genitals Thick/milky fluidThick/milky fluid

Pacinian Corpuscle: deep in the dermis; detects pressure

Close to the surface; light touch

Krause’s end bulb: touch/ low frequency vibration; cold

Thin Light Skin

Thick Light Skin

First Degree Burn: Epidermis only

First Degree Burn

Second Degree Burn: Epidermis and upper layers of the dermis

Second Degree Burn

Third Degree Burn: Complete destruction of the epidermis & dermis

Third Degree Burn

Third Degree Burns

Third Degree

Regeneration

Regeneration/Scarring

Skin graft donor site: about halfway through the initial healing stage

Papule Firm, raised lesion (less than 1cm in diameter)Firm, raised lesion (less than 1cm in diameter)

Papule

Plaque Large, raised lesion (greater than 1 cm in diameter)Large, raised lesion (greater than 1 cm in diameter)

Plaque

Vesicle Thin-walled blister filled w/ fluid, <1cmThin-walled blister filled w/ fluid, <1cm

Vesicle

Pustule Elevated lesion filled w/ pusElevated lesion filled w/ pus

Pustule

Crust Scab, area w/ dried blood or exudateScab, area w/ dried blood or exudate

Wheal Firm, raised area of irregular shape/light centerFirm, raised area of irregular shape/light center

Wheal

Macule Distinguished from surrounding skin by colorDistinguished from surrounding skin by color

Macule

Excoriation Epidermis is missing, dermis is exposedEpidermis is missing, dermis is exposed

Excoriation

Ulcer Craterlike lesion caused by disintegration of the skinCraterlike lesion caused by disintegration of the skin

Ulcer

Bed Sore

Fissure Linear crack or break from epidermis to dermisLinear crack or break from epidermis to dermis

Fissures