logging in or signing up tissues kati814m Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 572 Category: Education License: All Rights Reserved Like it (1) Dislike it (0) Added: March 07, 2009 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... By: janithbandara (17 month(s) ago) Please be kind enough to allow me to download this presentation iasjayantha@sltnet.lk Saving..... Post Reply Close Saving..... Edit Comment Close By: khanarif62 (27 month(s) ago) excellent presentation kindly post me the presentation best wishes thanking you khanarif62@gmail.com Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Slide 1: 5-1 Tissues Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Histology : 5-2 Histology Study of Tissues Four primary types of tissues Intercellular Junctions, Glands and Membranes The Study of Tissues : 5-3 The Study of Tissues Four primary tissue types: 1) epithelial tissue 2) connective tissue 3) muscular tissue 4) nervous tissue Histology (microscopic anatomy) study of tissues organ formation Organ = structure with discrete boundaries composed of 2 or more tissue types Major Themes of Anatomy and Physiology : 5-4 Major Themes of Anatomy and Physiology Features of Tissue Classes : 5-5 Features of Tissue Classes Tissue = similar cells and cell products arose from same region of embryo Differences between tissue classes types and functions of cells characteristics of matrix (extracellular material) fibrous proteins ground substance clear gels (ECF, tissue fluid, interstitial fluid, tissue gel) rubbery or stony in cartilage or bone space occupied by cells versus matrix connective tissue cells are widely separated little matrix between epithelial and muscle cells Embryonic Tissues : 5-6 Embryonic Tissues Embryo begins as single cell divides into many cells and layers 3 Primary germ layers ectoderm (outer) forms epidermis and nervous system endoderm (inner) forms mucous membrane lining GI tract and respiratory system and digestive glands mesoderm (middle) becomes mesenchyme wispy collagen fibers and fibroblasts in gel matrix gives rise to muscle, bone, blood (connective tissue) Epithelial Tissue : 5-7 Epithelial Tissue Layers of closely adhering cells Flat sheet with upper surface exposed to the environment or an internal body cavity No blood vessels underlying connective tissue supplies oxygen Rests on basement membrane Regenerates rapidly Functions of Epithelial Tissue : 5-8 Functions of Epithelial Tissue 1) protection 2) absorption 3) filtration 4) secretion (out of a cell, but within the body) 5) excretion (of wastes out of the body) 6) sensory reception Simple Versus Stratified Epithelia : 5-9 Simple Versus Stratified Epithelia Simple epithelium contains one layer of cells named by shape of cells -- Stratified epithelium contains more than one layer named by shape of apical cells Epithelial tissues : 5-10 Epithelial tissues Simple Squamous Epithelium : 5-11 Simple Squamous Epithelium Single row of flat cells Lining of cavities Secretes serous fluid Slide 12: 5-12 Simple Cuboidal Epithelium : 5-13 Simple Cuboidal Epithelium Single row cube-shaped cells Absorption and secretion Ducts of glands, kidney tubules Slide 14: 5-14 Simple Columnar Epithelium : 5-15 Simple Columnar Epithelium Single row tall, narrow cells oval nuclei in basal half of cell Absorption and high-volume secretion Lining of GI tract, uterus, kidney and uterine tubes Slide 16: 5-16 Note: glandular epithelium refers to layer of both simple columnar epithelium and mucous -secreting goblet cells Figure 5.6 : 5-17 Figure 5.6 Pseudostratified Epithelium : 5-18 Pseudostratified Epithelium Single row of cells some not reaching free surface nuclei give layer stratified look Secretes and propels respiratory mucus Figure 3.12a : 5-19 Figure 3.12a Figure 5.7 : 5-20 Figure 5.7 Slide 21: 5-21 Stratified Epithelia : 5-22 Stratified Epithelia More than one layer of cells Named for shape of surface cells exception is transitional epithelium Deepest cells on basement membrane Keratinized Stratified Squamous : 5-23 Keratinized Stratified Squamous Several layers of epithelium covered with dead squamous cells, packed with keratin epidermal layer of skin Retards water loss and barrier to organisms Figure 5.8 : 5-24 Figure 5.8 Slide 25: 5-25 Figure 5.12 : 5-26 Figure 5.12 Nonkeratinized Stratified Squamous : 5-27 Nonkeratinized Stratified Squamous Several layers of epithelium forming moist, slippery layer Tongue, oral mucosa, esophagus and vagina Slide 28: 5-28 Stratified Cuboidal Epithelium : 5-29 Stratified Cuboidal Epithelium Two or more cell layers; surface cells square Secretes sweat; produces sperm and hormones Sweat gland ducts; ovarian follicles and seminiferous tubules Figure 5.10 : 5-30 Figure 5.10 Transitional Epithelium : 5-31 Transitional Epithelium Multilayered epithelium surface cells that change from round to flat when stretched allows for filling of urinary tract ureter and bladder Figure 5.11 : 5-32 Figure 5.11 Connective Tissue : 5-33 Connective Tissue Widely spaced cells separated by fibers and ground substance (non-living matrix) Most abundant and variable tissue type Functions connects organs gives support and protection (physical and immune) stores energy and produces heat, insulation movement and transport of materials Cells of Connective Tissue : 5-34 Cells of Connective Tissue Fibroblasts produce fibers and ground substance Fibers of Connective Tissue : 5-35 Fibers of Connective Tissue Collagen fibers (white fibers) tough, stretch resistant, yet flexible tendons, ligaments and deep layer of the skin Reticular fibers thin, collagen fibers located in spleen and lymph nodes Elastic fibers (yellow fibers) thin branching fibers of elastin protein stretch and recoil like rubberband (elasticity) skin, lungs and arteries stretch and recoil Connective Tissue Ground Substance : 5-36 Connective Tissue Ground Substance Gelatinous material between cells absorbs compressive forces Fibrous Connective Tissue Types : 5-37 Fibrous Connective Tissue Types Loose connective tissue gel-like ground substance between cells types areolar reticular adipose Dense connective tissue fibers fill spaces between cells types vary in fiber orientation dense regular connective tissue dense irregular connective tissue Loose connective tissue : 5-38 Loose connective tissue Areolar Tissue : 5-39 Areolar Tissue Loose arrangement of fibers and cells in ground substance Functions: cushions organs Figure 5.14 : 5-40 Figure 5.14 Reticular Tissue : 5-41 Reticular Tissue Loose network of reticular fibers and cells Forms supportive framework for lymphatic organs Found in lymph nodes, spleen, thymus and bone marrow Figure 5.15 : 5-42 Figure 5.15 Adipose Tissue : 5-43 Adipose Tissue Empty-looking cells; nucleus pressed against cell membrane Energy storage, insulation, cushioning subcutaneous fat and organ packing brown fat (hibernating animals) produces heat Figure 5.16 : 5-44 Figure 5.16 Dense connective tissue : 5-45 Dense connective tissue Dense Regular Connective Tissue : 5-46 Dense Regular Connective Tissue Densely, packed, parallel collagen fibers Resistant to stretching Tendons and ligaments hold bones together and attach muscles to bones Figure 5.17 : 5-47 Figure 5.17 Dense Irregular Connective Tissue : 5-48 Dense Irregular Connective Tissue Densely packed, randomly arranged, collagen fibers and few visible cells withstands stresses applied in different directions deeper layer of skin; capsules around organs Figure 5.18 : 5-49 Figure 5.18 Cartilage : 5-50 Cartilage Supportive connective tissue with rubbery matrix No blood vessels diffusion brings nutrients and removes wastes heals slowly Types of cartilage vary with fiber types hyaline, fibrocartilage and elastic cartilage Hyaline Cartilage : 5-51 Hyaline Cartilage Rubbery matrix; dispersed collagen fibers; clustered chondrocytes in lacunae Provides reinforcement supports airway, eases joint movements Figure 5.19 : 5-52 Figure 5.19 Elastic Cartilage : 5-53 Elastic Cartilage Hyaline cartilage with elastic fibers Provides flexible, elastic support external ear Figure 5.20 : 5-54 Figure 5.20 Fibrocartilage : 5-55 Fibrocartilage Hyaline cartilage with extensive collagen fibers Resists compression and absorbs shock pubic symphysis Figure 5.21 : 5-56 Figure 5.21 Bone : 5-57 Bone Functions: calcium storage, support, muscle attachment, blood cell formation Bone Tissue (compact bone) : 5-58 Bone Tissue (compact bone) Calcified matrix around central canal Skeletal support; leverage for muscles; mineral storage Figure 5.22 : 5-59 Figure 5.22 Slide 60: 5-60 Slide 61: 5-61 Blood : 5-62 Blood Variety of cells and cell fragments; some with nuclei and some without Nonnucleated pale pink cells or nucleated white blood cells Found in heart and blood vessels Function: transport of nutrients, wastes, oxygen and carbon dioxide Figure 5.23 : 5-63 Figure 5.23 Slide 64: 5-64 Why is connective tissue so diverse? : 5-65 Why is connective tissue so diverse? Same Embryonic Origin:Mesoderm/Mesenchyme : 5-66 Same Embryonic Origin:Mesoderm/Mesenchyme Nerve Tissue(transmits information) : 5-67 Nerve Tissue(transmits information) Large cells with long cell processes surrounded by smaller glial cells lacking processes Internal communication between cells in brain, spinal cord, nerves and ganglia Communicates electrically Figure 5.24 : 5-68 Figure 5.24 Slide 69: 5-69 Muscle Tissue(specialized for contraction) : 5-70 Muscle Tissue(specialized for contraction) Elongated cells stimulated to contract Exert physical force on other tissues move limbs push blood through a vessel expel urine Source of body heat 3 histological types of muscle skeletal, cardiac and smooth Skeletal Muscle : 5-71 Skeletal Muscle Long, cylindrical, unbranched cells with striations and multiple nuclei movement, facial expression, posture, breathing, speech, swallowing and excretion Attached to bone (mostly), allows movement of skeleton Voluntary control Figure 5.25 : 5-72 Figure 5.25 Slide 73: 5-73 Cardiac Muscle : 5-74 Cardiac Muscle Short branched cells with striations and intercalated discs (type of gap junctions) one central nuclei per cell Pumping of blood by cardiac (heart) muscle Involuntary control Figure 5.26 : 5-75 Figure 5.26 Slide 76: 5-76 Smooth Muscle : 5-77 Smooth Muscle Short cells; nonstriated with only one central nucleus sheets of muscle in viscera; iris; hair follicles and sphincters (involuntary control) swallowing, GI tract functions, labor contractions, control of airflow, erection of hairs and control of pupil Figure 5.27 : 5-78 Figure 5.27 Intercellular Junctions : 5-79 Intercellular Junctions All cells (except blood) anchored to each other or their matrix by intercellular junctions Slide 80: 5-80 Tight Junctions : 5-81 Tight Junctions Encircle the cell joining it to surrounding cells; forms water-tight seal Prevents passage between cells GI and urinary tracts Desmosomes : 5-82 Desmosomes Patch between cells holding them together Most common type of cell junction Protect against mechanical stress Uterus, heart and epidermis Gap Junctions : 5-83 Gap Junctions Ring of transmembrane proteins form a channel small solutes pass directly from cell to cell Cell communication Endocrine and Exocrine Glands : 5-84 Endocrine and Exocrine Glands Secrete substances composed of epithelial tissue Exocrine glands connect to surface with a duct (epithelial tube) Endocrine glands secrete (hormones) directly into bloodstream Membrane Types : 5-85 Membrane Types Cutaneous membrane = skin stratified squamous epithelium relatively dry layer serves protective function Synovial membrane lines joint cavities connective tissue layer only, secretes synovial fluid Serous membrane (serosa) –internal membrane simple squamous epithelium over areolar tissue, produces serous fluid covers organs and lines walls of body cavities Mucous Membranes : 5-86 Mucous Membranes Lines passageways that open to the exterior: reproductive, respiratory, urinary and digestive Mucous (movement of cilia) trap and remove foreign particles and bacteria from internal body surfaces Membrane Types : 5-87 Membrane Types Cutaneous membrane = skin stratified squamous epithelium relatively dry layer serves protective function Synovial membrane lines joint cavities connective tissue layer only, secretes synovial fluid Serous membrane (serosa) –internal membrane simple squamous epithelium over areolar tissue, produces serous fluid covers organs and lines walls of body cavities Tissue Repair : 5-88 Tissue Repair Regeneration replacement of damaged cells with original cells skin injuries and liver regenerate Fibrosis replacement of damaged cells with scar tissue function is not restored healing muscle injuries, scarring of lung tissue in TB or healing of severe cuts and burns of the skin keloid is healing with excessive fibrosis (raised shiny scars) Figure 5.22 : 5-89 Figure 5.22 Figure 5.25 : 5-90 Figure 5.25 Figure 5.26b : 5-91 Figure 5.26b Figure 5.23 : 5-92 Figure 5.23 Figure 5.19 : 5-93 Figure 5.19 Figure 5.20 : 5-94 Figure 5.20 Figure 5.16 : 5-95 Figure 5.16 Figure 5.14 : 5-96 Figure 5.14 Slide 97: 5-97 Figure 5.17 : 5-98 Figure 5.17 You do not have the permission to view this presentation. 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tissues kati814m Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 572 Category: Education License: All Rights Reserved Like it (1) Dislike it (0) Added: March 07, 2009 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... By: janithbandara (17 month(s) ago) Please be kind enough to allow me to download this presentation iasjayantha@sltnet.lk Saving..... Post Reply Close Saving..... Edit Comment Close By: khanarif62 (27 month(s) ago) excellent presentation kindly post me the presentation best wishes thanking you khanarif62@gmail.com Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Slide 1: 5-1 Tissues Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Histology : 5-2 Histology Study of Tissues Four primary types of tissues Intercellular Junctions, Glands and Membranes The Study of Tissues : 5-3 The Study of Tissues Four primary tissue types: 1) epithelial tissue 2) connective tissue 3) muscular tissue 4) nervous tissue Histology (microscopic anatomy) study of tissues organ formation Organ = structure with discrete boundaries composed of 2 or more tissue types Major Themes of Anatomy and Physiology : 5-4 Major Themes of Anatomy and Physiology Features of Tissue Classes : 5-5 Features of Tissue Classes Tissue = similar cells and cell products arose from same region of embryo Differences between tissue classes types and functions of cells characteristics of matrix (extracellular material) fibrous proteins ground substance clear gels (ECF, tissue fluid, interstitial fluid, tissue gel) rubbery or stony in cartilage or bone space occupied by cells versus matrix connective tissue cells are widely separated little matrix between epithelial and muscle cells Embryonic Tissues : 5-6 Embryonic Tissues Embryo begins as single cell divides into many cells and layers 3 Primary germ layers ectoderm (outer) forms epidermis and nervous system endoderm (inner) forms mucous membrane lining GI tract and respiratory system and digestive glands mesoderm (middle) becomes mesenchyme wispy collagen fibers and fibroblasts in gel matrix gives rise to muscle, bone, blood (connective tissue) Epithelial Tissue : 5-7 Epithelial Tissue Layers of closely adhering cells Flat sheet with upper surface exposed to the environment or an internal body cavity No blood vessels underlying connective tissue supplies oxygen Rests on basement membrane Regenerates rapidly Functions of Epithelial Tissue : 5-8 Functions of Epithelial Tissue 1) protection 2) absorption 3) filtration 4) secretion (out of a cell, but within the body) 5) excretion (of wastes out of the body) 6) sensory reception Simple Versus Stratified Epithelia : 5-9 Simple Versus Stratified Epithelia Simple epithelium contains one layer of cells named by shape of cells -- Stratified epithelium contains more than one layer named by shape of apical cells Epithelial tissues : 5-10 Epithelial tissues Simple Squamous Epithelium : 5-11 Simple Squamous Epithelium Single row of flat cells Lining of cavities Secretes serous fluid Slide 12: 5-12 Simple Cuboidal Epithelium : 5-13 Simple Cuboidal Epithelium Single row cube-shaped cells Absorption and secretion Ducts of glands, kidney tubules Slide 14: 5-14 Simple Columnar Epithelium : 5-15 Simple Columnar Epithelium Single row tall, narrow cells oval nuclei in basal half of cell Absorption and high-volume secretion Lining of GI tract, uterus, kidney and uterine tubes Slide 16: 5-16 Note: glandular epithelium refers to layer of both simple columnar epithelium and mucous -secreting goblet cells Figure 5.6 : 5-17 Figure 5.6 Pseudostratified Epithelium : 5-18 Pseudostratified Epithelium Single row of cells some not reaching free surface nuclei give layer stratified look Secretes and propels respiratory mucus Figure 3.12a : 5-19 Figure 3.12a Figure 5.7 : 5-20 Figure 5.7 Slide 21: 5-21 Stratified Epithelia : 5-22 Stratified Epithelia More than one layer of cells Named for shape of surface cells exception is transitional epithelium Deepest cells on basement membrane Keratinized Stratified Squamous : 5-23 Keratinized Stratified Squamous Several layers of epithelium covered with dead squamous cells, packed with keratin epidermal layer of skin Retards water loss and barrier to organisms Figure 5.8 : 5-24 Figure 5.8 Slide 25: 5-25 Figure 5.12 : 5-26 Figure 5.12 Nonkeratinized Stratified Squamous : 5-27 Nonkeratinized Stratified Squamous Several layers of epithelium forming moist, slippery layer Tongue, oral mucosa, esophagus and vagina Slide 28: 5-28 Stratified Cuboidal Epithelium : 5-29 Stratified Cuboidal Epithelium Two or more cell layers; surface cells square Secretes sweat; produces sperm and hormones Sweat gland ducts; ovarian follicles and seminiferous tubules Figure 5.10 : 5-30 Figure 5.10 Transitional Epithelium : 5-31 Transitional Epithelium Multilayered epithelium surface cells that change from round to flat when stretched allows for filling of urinary tract ureter and bladder Figure 5.11 : 5-32 Figure 5.11 Connective Tissue : 5-33 Connective Tissue Widely spaced cells separated by fibers and ground substance (non-living matrix) Most abundant and variable tissue type Functions connects organs gives support and protection (physical and immune) stores energy and produces heat, insulation movement and transport of materials Cells of Connective Tissue : 5-34 Cells of Connective Tissue Fibroblasts produce fibers and ground substance Fibers of Connective Tissue : 5-35 Fibers of Connective Tissue Collagen fibers (white fibers) tough, stretch resistant, yet flexible tendons, ligaments and deep layer of the skin Reticular fibers thin, collagen fibers located in spleen and lymph nodes Elastic fibers (yellow fibers) thin branching fibers of elastin protein stretch and recoil like rubberband (elasticity) skin, lungs and arteries stretch and recoil Connective Tissue Ground Substance : 5-36 Connective Tissue Ground Substance Gelatinous material between cells absorbs compressive forces Fibrous Connective Tissue Types : 5-37 Fibrous Connective Tissue Types Loose connective tissue gel-like ground substance between cells types areolar reticular adipose Dense connective tissue fibers fill spaces between cells types vary in fiber orientation dense regular connective tissue dense irregular connective tissue Loose connective tissue : 5-38 Loose connective tissue Areolar Tissue : 5-39 Areolar Tissue Loose arrangement of fibers and cells in ground substance Functions: cushions organs Figure 5.14 : 5-40 Figure 5.14 Reticular Tissue : 5-41 Reticular Tissue Loose network of reticular fibers and cells Forms supportive framework for lymphatic organs Found in lymph nodes, spleen, thymus and bone marrow Figure 5.15 : 5-42 Figure 5.15 Adipose Tissue : 5-43 Adipose Tissue Empty-looking cells; nucleus pressed against cell membrane Energy storage, insulation, cushioning subcutaneous fat and organ packing brown fat (hibernating animals) produces heat Figure 5.16 : 5-44 Figure 5.16 Dense connective tissue : 5-45 Dense connective tissue Dense Regular Connective Tissue : 5-46 Dense Regular Connective Tissue Densely, packed, parallel collagen fibers Resistant to stretching Tendons and ligaments hold bones together and attach muscles to bones Figure 5.17 : 5-47 Figure 5.17 Dense Irregular Connective Tissue : 5-48 Dense Irregular Connective Tissue Densely packed, randomly arranged, collagen fibers and few visible cells withstands stresses applied in different directions deeper layer of skin; capsules around organs Figure 5.18 : 5-49 Figure 5.18 Cartilage : 5-50 Cartilage Supportive connective tissue with rubbery matrix No blood vessels diffusion brings nutrients and removes wastes heals slowly Types of cartilage vary with fiber types hyaline, fibrocartilage and elastic cartilage Hyaline Cartilage : 5-51 Hyaline Cartilage Rubbery matrix; dispersed collagen fibers; clustered chondrocytes in lacunae Provides reinforcement supports airway, eases joint movements Figure 5.19 : 5-52 Figure 5.19 Elastic Cartilage : 5-53 Elastic Cartilage Hyaline cartilage with elastic fibers Provides flexible, elastic support external ear Figure 5.20 : 5-54 Figure 5.20 Fibrocartilage : 5-55 Fibrocartilage Hyaline cartilage with extensive collagen fibers Resists compression and absorbs shock pubic symphysis Figure 5.21 : 5-56 Figure 5.21 Bone : 5-57 Bone Functions: calcium storage, support, muscle attachment, blood cell formation Bone Tissue (compact bone) : 5-58 Bone Tissue (compact bone) Calcified matrix around central canal Skeletal support; leverage for muscles; mineral storage Figure 5.22 : 5-59 Figure 5.22 Slide 60: 5-60 Slide 61: 5-61 Blood : 5-62 Blood Variety of cells and cell fragments; some with nuclei and some without Nonnucleated pale pink cells or nucleated white blood cells Found in heart and blood vessels Function: transport of nutrients, wastes, oxygen and carbon dioxide Figure 5.23 : 5-63 Figure 5.23 Slide 64: 5-64 Why is connective tissue so diverse? : 5-65 Why is connective tissue so diverse? Same Embryonic Origin:Mesoderm/Mesenchyme : 5-66 Same Embryonic Origin:Mesoderm/Mesenchyme Nerve Tissue(transmits information) : 5-67 Nerve Tissue(transmits information) Large cells with long cell processes surrounded by smaller glial cells lacking processes Internal communication between cells in brain, spinal cord, nerves and ganglia Communicates electrically Figure 5.24 : 5-68 Figure 5.24 Slide 69: 5-69 Muscle Tissue(specialized for contraction) : 5-70 Muscle Tissue(specialized for contraction) Elongated cells stimulated to contract Exert physical force on other tissues move limbs push blood through a vessel expel urine Source of body heat 3 histological types of muscle skeletal, cardiac and smooth Skeletal Muscle : 5-71 Skeletal Muscle Long, cylindrical, unbranched cells with striations and multiple nuclei movement, facial expression, posture, breathing, speech, swallowing and excretion Attached to bone (mostly), allows movement of skeleton Voluntary control Figure 5.25 : 5-72 Figure 5.25 Slide 73: 5-73 Cardiac Muscle : 5-74 Cardiac Muscle Short branched cells with striations and intercalated discs (type of gap junctions) one central nuclei per cell Pumping of blood by cardiac (heart) muscle Involuntary control Figure 5.26 : 5-75 Figure 5.26 Slide 76: 5-76 Smooth Muscle : 5-77 Smooth Muscle Short cells; nonstriated with only one central nucleus sheets of muscle in viscera; iris; hair follicles and sphincters (involuntary control) swallowing, GI tract functions, labor contractions, control of airflow, erection of hairs and control of pupil Figure 5.27 : 5-78 Figure 5.27 Intercellular Junctions : 5-79 Intercellular Junctions All cells (except blood) anchored to each other or their matrix by intercellular junctions Slide 80: 5-80 Tight Junctions : 5-81 Tight Junctions Encircle the cell joining it to surrounding cells; forms water-tight seal Prevents passage between cells GI and urinary tracts Desmosomes : 5-82 Desmosomes Patch between cells holding them together Most common type of cell junction Protect against mechanical stress Uterus, heart and epidermis Gap Junctions : 5-83 Gap Junctions Ring of transmembrane proteins form a channel small solutes pass directly from cell to cell Cell communication Endocrine and Exocrine Glands : 5-84 Endocrine and Exocrine Glands Secrete substances composed of epithelial tissue Exocrine glands connect to surface with a duct (epithelial tube) Endocrine glands secrete (hormones) directly into bloodstream Membrane Types : 5-85 Membrane Types Cutaneous membrane = skin stratified squamous epithelium relatively dry layer serves protective function Synovial membrane lines joint cavities connective tissue layer only, secretes synovial fluid Serous membrane (serosa) –internal membrane simple squamous epithelium over areolar tissue, produces serous fluid covers organs and lines walls of body cavities Mucous Membranes : 5-86 Mucous Membranes Lines passageways that open to the exterior: reproductive, respiratory, urinary and digestive Mucous (movement of cilia) trap and remove foreign particles and bacteria from internal body surfaces Membrane Types : 5-87 Membrane Types Cutaneous membrane = skin stratified squamous epithelium relatively dry layer serves protective function Synovial membrane lines joint cavities connective tissue layer only, secretes synovial fluid Serous membrane (serosa) –internal membrane simple squamous epithelium over areolar tissue, produces serous fluid covers organs and lines walls of body cavities Tissue Repair : 5-88 Tissue Repair Regeneration replacement of damaged cells with original cells skin injuries and liver regenerate Fibrosis replacement of damaged cells with scar tissue function is not restored healing muscle injuries, scarring of lung tissue in TB or healing of severe cuts and burns of the skin keloid is healing with excessive fibrosis (raised shiny scars) Figure 5.22 : 5-89 Figure 5.22 Figure 5.25 : 5-90 Figure 5.25 Figure 5.26b : 5-91 Figure 5.26b Figure 5.23 : 5-92 Figure 5.23 Figure 5.19 : 5-93 Figure 5.19 Figure 5.20 : 5-94 Figure 5.20 Figure 5.16 : 5-95 Figure 5.16 Figure 5.14 : 5-96 Figure 5.14 Slide 97: 5-97 Figure 5.17 : 5-98 Figure 5.17