chapter 5 the integumentary system and body membranes

Chapter 5Chapter 5The Integumentary System The Integumentary System

and Body Membranesand Body Membranes

Elsevier items and derived items © 2008, 2004 by Mosby, Inc., an affiliate of Elsevier Inc. Slide 2

CLASSIFICATION OF BODY CLASSIFICATION OF BODY MEMBRANESMEMBRANES

Classification of body membranes (Figure Classification of body membranes (Figure 5-1)5-1) Epithelial membranes—composed of epithelial Epithelial membranes—composed of epithelial

tissue and an underlying layer of connective tissue and an underlying layer of connective tissuetissue

Connective tissue membranes—composed Connective tissue membranes—composed largely of various types of connective tissuelargely of various types of connective tissue



Epithelial membranesEpithelial membranes Cutaneous membrane—the skinCutaneous membrane—the skin Serous membranes—simple squamous epithelium on a Serous membranes—simple squamous epithelium on a

connective tissue basement membraneconnective tissue basement membrane• TypesTypes

Parietal—line walls of body cavitiesParietal—line walls of body cavities Visceral—cover organs found in body cavitiesVisceral—cover organs found in body cavities

• ExamplesExamples Pleura—parietal and visceral layers line walls of thoracic Pleura—parietal and visceral layers line walls of thoracic

cavity and cover the lungscavity and cover the lungs Peritoneum—parietal and visceral layers line walls of Peritoneum—parietal and visceral layers line walls of

abdominal cavity and cover the organs in that cavityabdominal cavity and cover the organs in that cavity• DiseasesDiseases

Pleurisy—inflammation of the serous membranes that line Pleurisy—inflammation of the serous membranes that line the chest cavity and cover the lungsthe chest cavity and cover the lungs

Peritonitis—inflammation of the serous membranes in the Peritonitis—inflammation of the serous membranes in the abdominal cavity that line the walls and cover the abdominal abdominal cavity that line the walls and cover the abdominal organsorgans



Epithelial membranes (cont.)Epithelial membranes (cont.) Mucous membranesMucous membranes

• Line body surfaces that open directly to the exteriorLine body surfaces that open directly to the exterior

• Produce mucus, a thick secretion that keeps the Produce mucus, a thick secretion that keeps the membranes soft and moistmembranes soft and moist



Connective tissue membranesConnective tissue membranes Do not contain epithelial componentsDo not contain epithelial components Produce a lubricant called Produce a lubricant called synovial fluidsynovial fluid Examples are the synovial membranes in the Examples are the synovial membranes in the

spaces between joints and in the lining of spaces between joints and in the lining of bursal sacsbursal sacs


THE SKINTHE SKIN

Structure (Figure 5-2)—two primary layers called Structure (Figure 5-2)—two primary layers called epidermisepidermis and and dermisdermis EpidermisEpidermis

• Outermost and thinnest primary layer of skinOutermost and thinnest primary layer of skin• Composed of several layers of stratified squamous epitheliumComposed of several layers of stratified squamous epithelium• Stratum germinativum—innermost layer of cells that Stratum germinativum—innermost layer of cells that

continually reproduce; new cells move toward the surfacecontinually reproduce; new cells move toward the surface• As cells approach the surface, they are filled with a tough, As cells approach the surface, they are filled with a tough,

waterproof protein called waterproof protein called keratin;keratin; eventually cells flake off of eventually cells flake off of bodybody

• Stratum corneum—outermost layer of keratin-filled cellsStratum corneum—outermost layer of keratin-filled cells Skin pigment—produced by deepest epidermal layer; gives Skin pigment—produced by deepest epidermal layer; gives

color to the skincolor to the skin• The brown pigment melanin is produced by specialized cells The brown pigment melanin is produced by specialized cells

in deepest epidermal layerin deepest epidermal layer• Blisters—caused by breakdown of union between cells or Blisters—caused by breakdown of union between cells or

primary layers of skinprimary layers of skin


THE SKINTHE SKIN

Structure (cont.)Structure (cont.) Dermal-epidermal junction—specialized area between two Dermal-epidermal junction—specialized area between two

primary skin layersprimary skin layers DermisDermis

• Deeper and thicker of the two primary skin layers; composed Deeper and thicker of the two primary skin layers; composed largely of connective tissuelargely of connective tissue

• Upper papillary layer of dermis characterized by parallel rows Upper papillary layer of dermis characterized by parallel rows of tiny bumps called of tiny bumps called dermal papillaedermal papillae

• Ridges and grooves in dermis form pattern unique to each Ridges and grooves in dermis form pattern unique to each individualindividual

Basis of fingerprintingBasis of fingerprinting Improves grip for tool use and walkingImproves grip for tool use and walking

• Deeper reticular layer of dermis filled with network of tough, Deeper reticular layer of dermis filled with network of tough, interlacing, collagenous and stretchable elastic fibersinterlacing, collagenous and stretchable elastic fibers

Number of elastic fibers decreases with age and contributes to Number of elastic fibers decreases with age and contributes to wrinkle formationwrinkle formation

Dermis also contains nerve endings, muscle fibers, hair follicles, Dermis also contains nerve endings, muscle fibers, hair follicles, sweat and sebaceous glands, and many blood vesselssweat and sebaceous glands, and many blood vessels


THE SKINTHE SKIN

Accessory structures of the skinAccessory structures of the skin Hair (Figures 5-5)Hair (Figures 5-5)

• LanugoLanugo—soft hair of fetus and newborn—soft hair of fetus and newborn

• Hair follicleHair follicle—epidermal tubelike structure required —epidermal tubelike structure required for hair growthfor hair growth

• Hair papillaHair papilla—structure from which hair growth begins—structure from which hair growth begins

• Hair rootHair root—lies hidden in follicle—lies hidden in follicle

• Hair shaftHair shaft—visible part of hair—visible part of hair

• Arrector piliArrector pili—specialized smooth muscle that —specialized smooth muscle that produces “goose bumps” and causes hair to stand produces “goose bumps” and causes hair to stand up straightup straight


THE SKINTHE SKIN

Accessory structures of the skin (cont.)Accessory structures of the skin (cont.) Receptors (Figure 5-2)Receptors (Figure 5-2)

• Specialized nerve endingsSpecialized nerve endings—make it possible for skin —make it possible for skin to act as a sense organto act as a sense organ

• Meissner’s corpuscleMeissner’s corpuscle—capable of detecting light —capable of detecting light touchtouch

• Pacinian corpusclePacinian corpuscle—capable of detecting pressure—capable of detecting pressure


THE SKINTHE SKIN

Accessory structures of the skin (cont.)Accessory structures of the skin (cont.) Nails (Figure 5-6)Nails (Figure 5-6)

• Produced by epidermal cells over terminal ends of Produced by epidermal cells over terminal ends of fingers and toesfingers and toes

• Nail bodyNail body—visible part of nail—visible part of nail

• RootRoot—lies in a groove; hidden by cuticle—lies in a groove; hidden by cuticle

• LunulaLunula—crescent-shaped area nearest root—crescent-shaped area nearest root

• Nail bed may change color with change in blood flowNail bed may change color with change in blood flow


THE SKINTHE SKIN

Accessory structures of the skin (cont.)Accessory structures of the skin (cont.) Skin glands—two typesSkin glands—two types

• Sweat, or sudoriferous, glandsSweat, or sudoriferous, glands Eccrine sweat glandsEccrine sweat glands

– Most numerous, important, and wide-spread of the sweat glandsMost numerous, important, and wide-spread of the sweat glands– Produce perspiration or sweat, which flows out through pores on skin Produce perspiration or sweat, which flows out through pores on skin

surfacesurface– Function throughout life and assist in body heat regulationFunction throughout life and assist in body heat regulation

Apocrine sweat glandsApocrine sweat glands– Found primarily in axilla and around genitaliaFound primarily in axilla and around genitalia– Secrete a thicker secretion quite different from eccrine perspirationSecrete a thicker secretion quite different from eccrine perspiration– Breakdown of secretion by skin bacteria produces odorBreakdown of secretion by skin bacteria produces odor

• Sebaceous glandsSebaceous glands Secrete oil or sebum for hair and skinSecrete oil or sebum for hair and skin Level of secretion increases during adolescenceLevel of secretion increases during adolescence Amount of secretion is regulated by sex hormonesAmount of secretion is regulated by sex hormones Sebum in sebaceous gland ducts may darken to form a blackheadSebum in sebaceous gland ducts may darken to form a blackhead


THE SKINTHE SKIN

Skin cancer Skin cancer Functions of the skinFunctions of the skin

Protection—first line of defense against:Protection—first line of defense against:• Infection by microbesInfection by microbes

• Ultraviolet rays from sunUltraviolet rays from sun

• Harmful chemicalsHarmful chemicals

• Cuts and tearsCuts and tears


THE SKINTHE SKIN

Functions of the skin (cont.)Functions of the skin (cont.) Temperature regulationTemperature regulation

• Skin can release almost 3000 calories of body heat Skin can release almost 3000 calories of body heat per dayper day

Mechanisms of temperature regulationMechanisms of temperature regulation– Regulation of sweat secretionRegulation of sweat secretion– Regulation of blood flow close to the body surfaceRegulation of blood flow close to the body surface

Sense organ activitySense organ activity• Skin functions as an enormous sense organSkin functions as an enormous sense organ• Receptors serve as receivers for the body, keeping it Receptors serve as receivers for the body, keeping it

informed of changes in its environmentinformed of changes in its environment


THE SKINTHE SKIN

BurnsBurns Treatment and recovery or survival depend on Treatment and recovery or survival depend on

total area involved and severity or depth of the total area involved and severity or depth of the burnburn

Body surface area is estimated using the “rule Body surface area is estimated using the “rule of nines” (Figure 5-8) in adultsof nines” (Figure 5-8) in adults• Body is divided into 11 areas of 9% eachBody is divided into 11 areas of 9% each

• Additional 1% located around genitalsAdditional 1% located around genitals


THE SKINTHE SKIN

Burns (cont.)Burns (cont.) Classification of burnsClassification of burns

• First-degree (partial-thickness) burns—only the surface First-degree (partial-thickness) burns—only the surface layers of epidermis involvedlayers of epidermis involved

• Second-degree (partial-thickness) burns—involve the deep Second-degree (partial-thickness) burns—involve the deep epidermal layers and always cause injury to the upper epidermal layers and always cause injury to the upper layers of the dermislayers of the dermis

• Third-degree (full-thickness) burns—characterized by Third-degree (full-thickness) burns—characterized by complete destruction of the epidermis and dermiscomplete destruction of the epidermis and dermis

May involve underlying muscle and boneMay involve underlying muscle and bone Lesion is insensitive to pain because of destruction of nerve Lesion is insensitive to pain because of destruction of nerve

endings immediately after injury—intense pain is soon endings immediately after injury—intense pain is soon experiencedexperienced

Risk of infection is increasedRisk of infection is increased


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chapter 5 the integumentary system and body membranes

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abdominal organselsevier

layer of cells

synovial membranes

layer of keratin