Slide 0 Copyright © Mosby Inc. All Rights Reserved. Chapter 4 The Integumentary System and Body Membranes

Slide 1 Copyright © Mosby Inc. All Rights Reserved. Classifications of Body Membranes Classifications of body membranes (F 4-1)  Epithelial membranes— composed of epithelial tissues and an underlying layer of connective tissue  Connective tissue membranes—composed largely of various types of connective tissue

Slide 2 Copyright © Mosby Inc. All Rights Reserved. Classifications of Body Membranes Epithelial membranes  Cutaneous membrane—the skin  Serous membrane—simple squamous epithelium on a connective tissue basement membrane  Types o Parietal—lines walls of body cavities o Visceral—covers organs found in body cavities

Slide 3 Copyright © Mosby Inc. All Rights Reserved.  Examples o Pleura—parietal and visceral layers line walls of the thoracic cavity and cover the lungs o Peritoneum—parietal and visceral layers line the walls of the abdominal cavity and cover the organs in that cavity  Diseases o Pleurisy—inflammation of the serous membranes that line the chest cavity and cover the lungs o Peritonitis—inflammation of the serous membranes that line the walls of the abdominal cavity and cover the abdominal organs Classifications of Body Membranes

Slide 4 Copyright © Mosby Inc. All Rights Reserved. Classifications of Body Membranes  Mucous membranes  Line body surfaces that open directly to the exterior  Produce mucus, a thick secretion that keeps the membranes soft and moist (Cont’d…)

Slide 5 Copyright © Mosby Inc. All Rights Reserved. Classifications of Body Membranes Connective tissue membranes  Do not contain epithelial components  Produce a lubricant called synovial fluid  Examples are the synovial membranes in the spaces between joints and in the lining of bursal sacs

Slide 6 Copyright © Mosby Inc. All Rights Reserved. The Skin (F 4-2) Structure—two primary layers called epidermis and dermis  Epidermis  Outermost and thinnest primary layer of skin  Composed of several layers of stratified squamous epithelium  Stratum germinativum—innermost layer of cells that continually reproduce, and new cells move toward the surface

Slide 7 Copyright © Mosby Inc. All Rights Reserved. The Skin  As cells approach the surface, they are filled with a tough waterproof protein called keratin and eventually flake off  Stratum corneum—outermost layer of keratin- filled cells  Pigment-containing layer—epidermal layer that contains pigment cells called melanocytes, which produce the brown pigment melanin  Blisters—caused by breakdown of union between cells or primary layers of skin  Dermal—epidermal junction—specialized area between two primary skin layers

Slide 8 Copyright © Mosby Inc. All Rights Reserved. The Skin  Dermis  Deeper and thicker of the two primary skin layers and composed largely of connective tissue  Upper area of dermis characterized by parallel rows of peglike dermal papillae  Ridges and grooves in dermis form pattern unique to each individual o Basis of fingerprinting o Improves grip for tool use and walking

Slide 9 Copyright © Mosby Inc. All Rights Reserved. The Skin  Deeper areas of dermis filled with network of tough collagenous and stretchable elastic fibers  Number of elastic fibers decreases with age and contributes to wrinkle formation  Dermis also contains nerve endings, muscle fibers, hair follicles, sweat and sebaceous glands, and many blood vessels

Slide 10 Copyright © Mosby Inc. All Rights Reserved. (F 4-2)

Slide 11 Copyright © Mosby Inc. All Rights Reserved. The Skin Appendages of the skin  Hair (F 4-4)  Soft hair of fetus and newborn is called lanugo  Hair growth requires epidermal tubelike structure called hair follicle  Hair growth begins from hair papillae  Hair foot lies hidden in follicle and visible part of hair called shaft  Arrector pili—specialized smooth muscle that produces “goosebumps” and causes hair to stand straight up

Slide 12 Copyright © Mosby Inc. All Rights Reserved. The Skin  Receptors (F 4-6)  Specialized nerve endings—make it possible for skin to act as a sense organ  Meissner’s corpuscle—capable of detecting light touch  Pacinian corpuscle—capable of detecting pressure

Slide 13 Copyright © Mosby Inc. All Rights Reserved. The Skin  Nails (F 4-7)  Produced by epidermal cells over terminal ends of fingers and toes  Visible part is called nail body  Root lies in a groove and is hidden by cuticle  Crescent-shaped area nearest root is called lunula  Nail bed may change color with change in blood flow

Slide 14 Copyright © Mosby Inc. All Rights Reserved. The Skin  Skin glands  Types o Sweat or sudoriferous o Sebaceous

Slide 15 Copyright © Mosby Inc. All Rights Reserved. The Skin  Sweat or sebaceous glands o Types Eccrine sweat glands Most numerous, important, and widespread of the sweat glands Produce perspiration or sweat, which flows out through pores on skin surface Function throughout life and assist in body heat regulation

Slide 16 Copyright © Mosby Inc. All Rights Reserved. The Skin Apocrine sweat glands  Found primarily in axilla and around genitalia  Secrete a thicker secretion quite different from eccrine perspiration  Breakdown of secretion by skin bacteria produces odor

Slide 17 Copyright © Mosby Inc. All Rights Reserved. The Skin  Sebaceous glands o Secrete oil or sebum for hair and skin o Level of secretion increases during adolescence o Amount of secretion is regulated by sex hormones o Sebum in sebaceous gland ducts may darken to form a blackhead

Slide 18 Copyright © Mosby Inc. All Rights Reserved. The Skin Functions of the skin  Protection—first line of defense:  Against infection by microbes  Against ultraviolet rays from the sun  Against harmful chemicals  Against cuts and tears

Slide 19 Copyright © Mosby Inc. All Rights Reserved. The Skin  Temperature regulation  Skin can release almost 3000 calories of body heat per day o Mechanisms of temperature regulation Regulation of sweat secretion Regulation of flow of blood close to the body surface

Slide 20 Copyright © Mosby Inc. All Rights Reserved. The Skin  Sense organ activity  Skin functions as an enormous sense organ  Receptors serve as receivers for the body, keeping it informed of changes in its environment

Slide 21 Copyright © Mosby Inc. All Rights Reserved. The Skin Burns (F 4-8)  Treatment and recovery or survival depend on total area involved and severity or depth of burn  Body surface area is estimated using the “rule of nines” in adults  Body is divided into 11 areas of 9% each

Slide 22 Copyright © Mosby Inc. All Rights Reserved. The Skin  Classification of burns  First-degree (partial- thickness) burns—only the surface layers of epidermis involved  Second-degree (partial- thickness) burns— involve the deep epidermal layers and always cause injury to the upper layers of the dermis

Slide 23 Copyright © Mosby Inc. All Rights Reserved. The Skin  Third-degree (full-thickness) burns—characterized by complete destruction of the epidermis and dermis o May involve underlying muscle and bone o Lesion is insensitive to pain because of destruction of nerve endings immediately after injury—intense pain is soon experienced o Risk of infection is increased

Slide 24 Copyright © Mosby Inc. All Rights Reserved.