Fundamentals of Anatomy & Physiology Chapter 4

Fundamentals of Anatomy & Physiology Eleventh Edition Chapter 4 The Tissue Level of Organization Lecture Presentation by Debora...

Fundamentals of Anatomy & Physiology Eleventh Edition Chapter 4 The Tissue Level of Organization Lecture Presentation by Deborah A. Hutchinson Seattle University © 2018 Pearson Education, Inc.  Learning Outcomes 4-1 Identify the four major types of tissues in the body, and describe their roles. 4-2 Discuss the types and functions of epithelial tissue. 4-3 Describe the relationship between structure and function for each type of epithelium. 4-4 List the specific functions of connective tissue, and describe the three main categories of connective tissue. 4-5 Compare the structures and functions of the various types of connective tissue proper, and the layers of connective tissue called fasciae. 4-6 Describe the fluid connective tissues blood and lymph, and explain their relationship with interstitial fluid in maintaining homeostasis. 2 © 2018 Pearson Education, Inc.  Learning Outcomes 4-7 Describe how cartilage and bone function as supporting connective tissues. 4-8 Explain how epithelial and connective tissues combine to form four types of tissue membranes, and specify the functions of each. 4-9 Describe the three types of muscle tissue and the special structural features of each type. 4-10 Discuss the basic structure and role of nervous tissue. 4-11 Describe how injuries affect the tissues of the body. 4-12 Describe how aging affects the tissues of the body. 3 © 2018 Pearson Education, Inc.  An Introduction to Tissues  Tissues – Collections of specialized cells and cell products that perform specific functions – Tissues in combination form organs, such as the heart or liver – Histology is the study of tissues 4 © 2018 Pearson Education, Inc.  4-1 Four Types of Tissue  Four types of tissue 1. Epithelial 2. Connective 3. Muscle 4. Nervous 5 © 2018 Pearson Education, Inc.  4-1 Four Types of Tissue  Epithelial tissue – Covers exposed surfaces – Lines internal passageways – Forms glands  Connective tissue – Fills internal spaces – Supports other tissues – Transports materials – Stores energy 6 © 2018 Pearson Education, Inc.  4-1 Four Types of Tissue  Muscle tissue – Specialized for contraction – Skeletal muscle, heart muscle, and muscular walls of hollow organs  Nervous tissue – Carries electrical signals from one part of the body to another 7 © 2018 Pearson Education, Inc. Figure 4–1 An Orientation to the Body’s Tissues. Secrete and regulate EXTRACELLULAR CELLS MATERIAL AND FLUIDS Combine to form TISSUES with special functions EPITHELIAL TISSUE CONNECTIVE TISSUE MUSCLE TISSUE NERVOUS TISSUE Covers exposed Fills internal Contracts to Propagates surfaces spaces produce electrical Lines internal movement impulses Provides passageways Carries structural and chambers support information Produces Stores glandular energy secretions Combine to form ORGANS with multiple functions Interact in ORGAN SYSTEMS 8 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Epithelial tissue includes epithelia and glands – Epithelia (singular, epithelium) Layers of cells covering internal or external surfaces – Glands Structures that produce fluid secretions 9 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Functions of epithelial tissue 1. Provide physical protection 2. Control permeability 3. Provide sensation 4. Produce specialized secretions 10 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Characteristics of epithelia – Polarity (apical and basal surfaces) – Cellularity (cell junctions) – Attachment (basement membrane) – Avascularity (avascular) – Regeneration 11 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Specializations of epithelial cells 1. Move fluids over the epithelium (protection) 2. Move fluids through the epithelium (permeability) 3. Produce secretions (protection and messaging)  Polarity – Apical surface Microvilli increase absorption or secretion Cilia on a ciliated epithelium move fluids – Basolateral surface 12 © 2018 Pearson Education, Inc. Figure 4–2 The Polarity of Epithelial Cells. Cilia Microvilli Apical surface Lateral surfaces Golgi apparatus Nucleus Mitochondria Basement membrane Basal surface 13 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Integrity of epithelia is maintained by 1. Intercellular connections 2. Attachment to the basement membrane 3. Epithelial maintenance and repair 14 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Intercellular connections – Support and communication Cell adhesion molecules (CAMs) – Transmembrane proteins Proteoglycans act as intercellular cement – Contain glycosaminoglycans such as hyaluronan (hyaluronic acid) 15 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Intercellular connections – Cell junctions Form bonds with other cells or extracellular material 1. Gap junctions 2. Tight junctions 3. Desmosomes 16 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Gap junctions – Allow rapid communication – Cells held together by interlocking transmembrane proteins (connexons) – Allow small molecules and ions to pass – Coordinate contractions in heart muscle 17 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Tight junctions – Between two plasma membranes – Adhesion belt attaches to terminal web – Prevent passage of water and solutes – Keep enzymes, acids, and wastes in the lumen of the digestive tract 18 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Desmosomes – CAMs and proteoglycans link opposing plasma membranes – Spot desmosomes Tie cells together Allow bending and twisting – Hemidesmosomes Attach cells to the basement membrane 19 © 2018 Pearson Education, Inc. Figure 4–3a Cell Junctions. Tight junction Adhesion belt Terminal web Gap junctions Spot desmosome Hemidesmosome a View of an epithelial cell, showing the major types of intercellular connections. 20 © 2018 Pearson Education, Inc. Figure 4–3b Cell Junctions. Embedded proteins (connexons) b Gap junctions permit the free diffusion of ions and small molecules between two cells. 21 © 2018 Pearson Education, Inc. Figure 4–3c Cell Junctions. Interlocking junctional proteins Tight junction Terminal web Adhesion belt c A tight junction is formed by the fusion of the outer layers of two plasma membranes. Tight junctions prevent the diffusion of fluids and solutes between the cells. A continuous adhesion belt lies deep to the tight junction. This belt is tied to the © 2018 Pearson Education, Inc. microfilaments of the terminal web. 22 Figure 4–3d Cell Junctions. Intermediate filaments Cell adhesion molecules (CAMs) Dense area Proteoglycans d A spot desmosome ties adjacent cells together. 23 © 2018 Pearson Education, Inc. Figure 4–3e Cell Junctions. Basal lamina Basement Reticular membrane lamina e Hemidesmosomes attach a cell to extracellular structures, such as the protein fibers in the basement membrane. 24 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Attachment to the basement membrane – Basal lamina Closest to the epithelium – Reticular lamina Deeper portion of basement membrane Provides strength 25 © 2018 Pearson Education, Inc.  4-2 Epithelial Tissue  Epithelial maintenance and repair – Epithelial cells are replaced by continual division of stem cells Located near basement membrane 26 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Classification of epithelia 1. Based on shape Squamous—thin and flat Cuboidal—square shaped Columnar—tall, slender rectangles 2. Based on layers Simple epithelium—single layer of cells Stratified epithelium—several layers of cells 27 © 2018 Pearson Education, Inc. Table 4-1 Classifying Epithelia (Part 1 of 2) 28 © 2018 Pearson Education, Inc. Table 4-1 Classifying Epithelia (Part 2 of 2) 29 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Squamous epithelia – Simple squamous epithelia Absorption and diffusion Mesothelium – Lines body cavities Endothelium – Forms inner lining of heart and blood vessels – Stratified squamous epithelia Protect against mechanical stresses Keratin adds strength and water resistance 30 © 2018 Pearson Education, Inc. Figure 4–4a Squamous Epithelia. a Simple Squamous Epithelium LOCATIONS: Mesothelia lining pleural, pericardial, and peritoneal cavities; Cytoplasm endothelia lining heart and blood vessels; portions of kidney tubules (thin Nucleus sections of nephron loops); inner lining of cornea; alveoli of lungs FUNCTIONS: Reduces friction; controls vessel permeability; performs Connective tissue LM × 238 absorption and secretion Lining of peritoneal cavity 31 © 2018 Pearson Education, Inc. Figure 4–4b Squamous Epithelia. b Stratified Squamous Epithelium LOCATIONS: Surface of skin; lining of mouth, throat, Squamous esophagus, rectum, anus, superficial cells and vagina FUNCTIONS: Provides physical protection against abrasion, Stem cells pathogens, and chemical attack Basement membrane Connective tissue Surface of tongue LM × 310 32 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Cuboidal epithelia – Simple cuboidal epithelia Secretion and absorption Glands and portions of kidney tubules – Stratified cuboidal epithelia Relatively rare Ducts of sweat glands and mammary glands 33 © 2018 Pearson Education, Inc. Figure 4–5a Cuboidal and Transitional Epithelia. a Simple Cuboidal Epithelium LOCATIONS: Glands; ducts; portions of kidney tubules; thyroid gland FUNCTIONS: Limited protection, Connective secretion, absorption tissue Nucleus Cuboidal cells Basement membrane Kidney tubule LM × 650 34 © 2018 Pearson Education, Inc. Figure 4–5b Cuboidal and Transitional Epithelia. b Stratified Cuboidal Epithelium LOCATIONS: Lining of some ducts (rare) FUNCTIONS: Protection, secretion, Lumen absorption of duct Stratified cuboidal cells Basement membrane Nucleus Connective tissue Sweat gland duct LM × 500 35 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Transitional epithelia – Tolerate repeated cycles of stretching without damage – Appearance changes as stretching occurs – Found in urinary bladder 36 © 2018 Pearson Education, Inc. Figure 4–5c Cuboidal and Transitional Epithelia. c Transitional Epithelium LOCATIONS: Urinary bladder; renal pelvis; ureters FUNCTIONS: Permits Epithelium repeated cycles of (not stretched) stretching without damage Basement membrane Connective tissue and Empty bladder smooth muscle layers LM × 400 Epithelium (stretched) Basement membrane Connective tissue and Full bladder smooth muscle layers LM × 400 Urinary bladder 37 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Columnar epithelia – Simple columnar epithelia Absorption and secretion Found in stomach, small intestine, large intestine – Pseudostratified columnar epithelia Typically have cilia Found in nasal cavity, trachea, bronchi – Stratified columnar epithelia Relatively rare Provide protection in pharynx, anus, urethra 38 © 2018 Pearson Education, Inc. Figure 4–6a Columnar Epithelia. a Simple Columnar Epithelium LOCATIONS: Lining of stomach, intestine, gallbladder, Microvilli uterine tubes, and collecting Cytoplasm ducts of kidneys FUNCTIONS: Protection, Nucleus secretion, absorption Basement membrane Loose connective tissue LM × 350 Intestinal lining 39 © 2018 Pearson Education, Inc. Figure 4–6b Columnar Epithelia. b Pseudostratified Ciliated Columnar Epithelium LOCATIONS: Lining of nasal cavity, trachea, and Cilia bronchi; portions of male reproductive tract Cytoplasm FUNCTIONS: Protection, secretion, move mucus Nuclei with cilia Basement membrane Loose connective tissue Trachea LM × 350 40 © 2018 Pearson Education, Inc. Figure 4–6c Columnar Epithelia. c Stratified Columnar Epithelium LOCATIONS: Small areas of the pharynx, epiglottis, anus, Loose mammary glands, salivary connective tissue gland ducts, and urethra Deeper cells FUNCTION: Protection Superficial Lumen columnar cells Lumen Cytoplasm Nuclei Basement Salivary gland duct membrane LM × 175 41 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Glandular epithelia – Glands are collections of epithelial cells that produce secretions – Endocrine glands Release hormones that enter bloodstream No ducts – Exocrine glands Produce exocrine secretions Discharge secretions through ducts onto epithelial surfaces 42 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Gland structure – Unicellular glands – Multicellular glands  Unicellular glands – Goblet cells are unicellular exocrine glands In epithelia of intestines Secrete mucin, which mixes with water to form mucus 43 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Multicellular exocrine glands are classified by 1. Structure of the duct Simple (undivided) Compound (divided) 2. Shape of secretory portion of the gland Tubular (tube shaped) Alveolar or acinar (blind pockets) 3. Relationship between ducts and glandular areas Branched (several secretory areas sharing one duct) 44 © 2018 Pearson Education, Inc. Figure 4–7a A Structural Classification of Exocrine Glands. a Simple Glands Duct Gland cells SIMPLE SIMPLE COILED SIMPLE BRANCHED SIMPLE ALVEOLAR SIMPLE BRANCHED TUBULAR TUBULAR TUBULAR (ACINAR) ALVEOLAR Examples: Examples: Examples: Examples: Examples: Intestinal glands Merocrine sweat Gastric glands Not found in adult; a Sebaceous (oil) glands Mucous glands stage in development glands of esophagus, of simple branched tongue, duodenum glands 45 © 2018 Pearson Education, Inc. Figure 4–7b A Structural Classification of Exocrine Glands. b Compound Glands COMPOUND COMPOUND ALVEOLAR COMPOUND TUBULAR (ACINAR) TUBULO-ALVEOLAR Examples: Examples: Examples: Mucous glands (in mouth) Mammary glands Salivary glands Bulbo-urethral glands (in Glands of respiratory male reproductive system) passages Testes (seminiferous tubules) Pancreas 46 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Methods of secretion 1. Merocrine 2. Apocrine 3. Holocrine 47 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Merocrine secretion – Released by secretory vesicles (exocytosis) – Example: merocrine sweat glands  Apocrine secretion – Released by shedding cytoplasm – Example: mammary glands 48 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Holocrine secretion – Released by cells bursting, killing gland cells – Gland cells replaced by stem cells – Example: sebaceous glands 49 © 2018 Pearson Education, Inc. Figure 4–8a Methods of Glandular Secretion. a Merocrine secretion In merocrine secretion, the product is released from secretory vesicles at the apical surface of the gland cell by exocytosis. Secretory vesicle Golgi apparatus Nucleus TEM × 3039 Salivary gland Mammary gland 50 © 2018 Pearson Education, Inc. Figure 4–8b Methods of Glandular Secretion. Salivary gland b Apocrine secretion Apocrine secretion involves the loss of apical cytoplasm. Inclusions, secretory vesicles, and other cytoplasmic components Mammary are shed in the process. The gland cell then grows and repairs gland itself before it releases additional secretions. Breaks down Golgi apparatus Secretion Regrowth 1 2 3 4 51 © 2018 Pearson Education, Inc. Figure 4–8c Methods of Glandular Secretion. Salivary gland Mammary gland Hair Sebaceous gland Hair follicle c Holocrine secretion Holocrine secretion occurs as superficial gland cells burst. Continued secretion involves the replacement of these cells through the mitotic divisions of underlying stem cells. 3 Cells burst, releasing cytoplasmic contents 2 Cells form secretory products and increase in size 1 Cell division replaces lost cells Stem cell 52 © 2018 Pearson Education, Inc.  4-3 Classification of Epithelia  Types of secretions produced by exocrine glands – Serous glands Watery secretions – Mucous glands Secrete mucins – Mixed exocrine glands Both serous and mucous 53 © 2018 Pearson Education, Inc.  4-4 Connective Tissue  Components of connective tissues 1. Specialized cells 2. Extracellular protein fibers 3. Fluid called ground substance  Matrix consists of extracellular components of connective tissue (fibers and ground substance) – Majority of tissue volume – Determines specialized function 54 © 2018 Pearson Education, Inc.  4-4 Connective Tissue  Functions of connective tissues – Establishing a structural framework for the body – Transporting fluids and dissolved materials – Protecting delicate organs – Supporting, surrounding, and interconnecting other types of tissue – Storing energy reserves, especially triglycerides – Defending the body from invading microorganisms 55 © 2018 Pearson Education, Inc.  4-4 Connective Tissue  Categories of connective tissues 1. ​Connective tissue proper Connect and protect 2. ​Fluid connective tissues Transport 3. ​Supporting connective tissues Structural strength 56 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Categories of connective tissue proper – Loose connective tissue More ground substance, fewer fibers Example: fat (adipose tissue) – Dense connective tissue More fibers, less ground substance Example: tendons 57 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Cells of connective tissue proper – Fibroblasts – Fibrocytes – Adipocytes – Mesenchymal cells – Melanocytes – Macrophages – Mast cells – Lymphocytes – Microphages 58 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Fibroblasts – The most abundant cell type – Found in all types of connective tissue proper – Secrete proteins and hyaluronan (cellular cement)  Fibrocytes – Second most abundant cell type – Maintain connective tissue fibers 59 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Adipocytes – Fat cells – Each cell stores a single, large fat droplet  Mesenchymal cells – Stem cells that respond to injury or infection – Differentiate into fibroblasts, macrophages, etc.  Melanocytes – Synthesize and store the brown pigment melanin 60 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Macrophages – Large phagocytic cells of the immune system – Engulf pathogens and damaged cells – Fixed macrophages stay in tissue – Free macrophages migrate  Mast cells – Stimulate inflammation after injury or infection Release histamine and heparin – Basophils are leukocytes that also contain histamine and heparin 61 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Lymphocytes – Migrate throughout the body – May develop into plasma cells, which produce antibodies  Microphages – Phagocytic blood cells (neutrophils, eosinophils) – Attracted to signals from macrophages and mast cells 62 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Connective tissue fibers 1. Collagen fibers 2. Reticular fibers 3. Elastic fibers 63 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Collagen fibers – Most common fibers in connective tissue proper – Long, straight, and unbranched – Strong and flexible – Resist force in one direction – Abundant in tendons and ligaments 64 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Reticular fibers – Form a network of interwoven fibers (stroma) – Strong and flexible – Resist forces in many directions – Stabilize functional cells (parenchyma) and structures – Example: sheaths around organs 65 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Elastic fibers – Contain elastin – Branched and wavy – Return to original length after stretching – Example: elastic ligaments of vertebrae 66 © 2018 Pearson Education, Inc. Figure 4–9 The Cells and Fibers of Connective Tissue Proper. Reticular fibers Mast cell Melanocyte Elastic Fixed fibers macrophage Plasma cell Free macrophage Collagen fibers Blood in vessel Fibroblast Fibrocyte Mesenchymal Adipocytes cell (fat cells) Ground Lymphocyte substance 67 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Ground substance – Is clear, colorless, and viscous – Fills spaces between cells and slows pathogen movement  Loose connective tissues – “Packing materials” – Fill spaces between organs, cushion cells, and support epithelia 68 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Embryonic connective tissues – Not found in adults – Mesenchyme (embryonic connective tissue) First connective tissue in embryos – Mucous connective tissue Loose embryonic connective tissue 69 © 2018 Pearson Education, Inc. Figure 4–10a Embryonic Connective Tissues. Blood vessel Mesenchymal cells Mesenchyme LM × 136 a This is the first connective tissue to appear in an embryo. 70 © 2018 Pearson Education, Inc. Figure 4–10b Embryonic Connective Tissues. Blood vessel Mesenchymal cells Mucous connective tissue LM × 136 (Wharton’s jelly) b This sample was taken from the umbilical cord of a fetus. 71 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Types of loose connective tissues in adults 1. Areolar tissue 2. Adipose tissue 3. Reticular tissue 72 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Areolar tissue – Least specialized – Open framework – Viscous ground substance – Elastic fibers – Holds capillary beds Example: under skin (subcutaneous layer) 73 © 2018 Pearson Education, Inc. Figure 4–11a Loose Connective Tissues. a Areolar Tissue LOCATIONS: Within and deep to the dermis of skin, and covered by the epithelial lining of the digestive, respiratory, and urinary tracts; Fibrocytes between muscles; around joints, blood vessels, and nerves Macrophage Collagen FUNCTIONS: Cushions organs; provides fibers support but permits independent movement; phagocytic Mast cell cells provide defense against pathogens Areolar Elastic fibers tissue from LM × 380 pleura Areolar tissue 74 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Adipose tissue – Contains many adipocytes (fat cells) Adipocytes in adults do not divide – Expand to store fat – Shrink as fats are released Mesenchymal cells divide and differentiate – To produce more fat cells – When more storage is needed – May be removed (temporarily) via liposuction in cosmetic surgery 75 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  White fat – Most common – Stores fat and absorbs shocks – Slows heat loss (insulation)  Brown fat – Found in babies and young children – More vascularized – Adipocytes have many mitochondria – Breakdown of lipids releases energy and warms body 76 © 2018 Pearson Education, Inc. Figure 4–11b Loose Connective Tissues. b Adipose Tissue LOCATIONS: Deep to the skin, especially at sides, buttocks, and breasts; padding around eyes and kidneys FUNCTIONS: Provides padding and cushions Adipocytes shocks; insulates (white adipose (reduces heat loss); cells) stores energy LM × 300 Adipose tissue 77 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Reticular tissue – Provides support – Reticular fibers form a complex, three-dimensional stroma – Support functional cells of organs – Found in liver, kidney, spleen, lymph nodes, and bone marrow 78 © 2018 Pearson Education, Inc. Figure 4–11c Loose Connective Tissues. c Reticular Tissue LOCATIONS: Liver, kidney, spleen, lymph nodes, and bone marrow FUNCTIONS: Provides supporting framework Reticular fibers Reticular tissue from liver LM × 230 Reticular tissue 79 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Dense connective tissues – Also called collagenous tissues Contain many collagen fibers – Three types of dense connective tissues Dense regular Dense irregular Elastic 80 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Dense regular connective tissue – Tightly packed, parallel collagen fibers Tendons attach muscles to bones Ligaments connect one bone to another and stabilize organs Aponeuroses are tendinous sheets that attach a broad, flat muscle to another structure 81 © 2018 Pearson Education, Inc. Figure 4–12a Dense Connective Tissues. a Dense Regular Connective Tissue LOCATIONS: Between skeletal muscles and skeleton (tendons and aponeuroses); between bones or stabilizing positions Collagen of internal organs (ligaments); fibers covering skeletal muscles; deep fasciae FUNCTIONS: Provides firm attachment; conducts Fibroblast pull of muscles; reduces nuclei friction between muscles; stabilizes positions of bones Tendon LM × 440 82 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Dense irregular connective tissue – Interwoven network of collagen fibers Provides strength to dermis Forms sheath around cartilages (perichondrium) and bones (periosteum) Forms capsules around some organs (e.g., liver, kidneys, and spleen) 83 © 2018 Pearson Education, Inc. Figure 4–12b Dense Connective Tissues. b Dense Irregular Connective Tissue LOCATIONS: Capsules of visceral organs; periostea and perichondria; nerve and muscle sheaths; dermis FUNCTIONS: Provides strength to resist forces Collagen from many directions; fiber helps prevent bundles overexpansion of organs, such as the urinary bladder Deep dermis LM × 111 84 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Elastic tissue – Made of elastic fibers Example: elastic ligaments of spinal vertebrae 85 © 2018 Pearson Education, Inc. Figure 4–12c Dense Connective Tissues. c Elastic Tissue LOCATIONS: Between vertebrae of the spinal column (ligamenta flava and ligamentum nuchae); ligaments supporting penis; ligaments supporting transitional Elastic epithelia; in blood vessel walls fibers FUNCTIONS: Stabilizes positions of vertebrae and Fibroblast penis; cushions shocks; nuclei permits expansion and contraction of organs Elastic ligament LM × 887 86 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Connective tissues 1. Provide strength and stability 2. Maintain positions of internal organs 3. Provide routes for blood vessels, lymphatic vessels, and nerves  Fasciae (singular, fascia) – Connective tissue layers and wrappings that support and surround organs 87 © 2018 Pearson Education, Inc.  4-5 Connective Tissue Proper  Three layers of fasciae 1. ​Superficial fascia Separates skin from underlying tissues 2. ​Deep fascia Sheets of dense regular connective tissue 3. ​Subserous fascia Lies between deep fascia and serous membranes that line body cavities 88 © 2018 Pearson Education, Inc. Figure 4–13 The Fasciae. Body wall Connective Tissue Framework of Body Body cavity Superficial Fascia Between skin and underlying organs Areolar tissue and adipose tissue Also known as subcutaneous layer or hypodermis Skin Deep Fascia Bound to capsules, tendons, and ligaments Dense connective tissue Forms a strong, fibrous internal framework Subserous Fascia Between serous membranes and deep fascia Areolar tissue Rib Serous membrane Cutaneous membrane 89 © 2018 Pearson Education, Inc.  4-6 Blood and Lymph  Fluid connective tissues include blood and lymph  Blood – Contains a watery matrix called plasma – Contains cells and cell fragments, collectively known as formed elements Red blood cells (erythrocytes) White blood cells (leukocytes) Platelets 90 © 2018 Pearson Education, Inc. Figure 4–14 Formed Elements in the Blood (Part 1 of 3). Red blood cells Red blood cells, or erythrocytes (e-RITH-rō-sīts), transport oxygen (and, to a lesser degree, carbon dioxide) in the blood. Red blood cells lack a nucleus. They account for about half the volume of whole blood and give blood its color. 91 © 2018 Pearson Education, Inc. Figure 4–14 Formed Elements in the Blood (Part 2 of 3). White blood cells White blood cells, or leukocytes (LŪ-kō-sīts; leuko-, white), are nucleated cells, which defend the body from infection and disease. Neutrophil Eosinophil Basophil Monocytes Lymphocytes are un- Eosinophils and neutrophils are phagocytes common in the blood but are phagocytes (microphages). similar to the they are the dominant cell Basophils promote inflamma- free macro- type in lymph, the second tion much like mast cells in phages in type of fluid connective other connective tissues. other tissues. tissue. 92 © 2018 Pearson Education, Inc. Figure 4–14 Formed Elements in the Blood (Part 3 of 3). Platelets Platelets are membrane- enclosed packets of cytoplasm that function in blood clotting. These cell fragments are involved in the clotting response that seals leaks in damaged or broken blood vessels. 93 © 2018 Pearson Education, Inc.  4-6 Blood and Lymph  Lymph – Forms as interstitial fluid that enters lymphatic vessels – Monitored by immune system – Returned to veins near the heart 94 © 2018 Pearson Education, Inc.  4-7 Supporting Connective Tissues  Supporting connective tissues include cartilage and bone  Cartilage – Provides shock absorption and protection – Matrix is a firm gel Contains polysaccharide derivatives called chondroitin sulfates – Cells in the matrix are chondrocytes In chambers called lacunae 95 © 2018 Pearson Education, Inc.  4-7 Supporting Connective Tissues  Cartilage structure – Avascular Chondrocytes produce antiangiogenesis factor that discourages formation of blood vessels – Perichondrium Outer, fibrous layer (for support and protection) Inner, cellular layer (for growth and maintenance) 96 © 2018 Pearson Education, Inc.  4-7 Supporting Connective Tissues  Types of cartilage 1. Hyaline cartilage 2. Elastic cartilage 3. Fibrocartilage 97 © 2018 Pearson Education, Inc.  4-7 Supporting Connective Tissues  Hyaline cartilage – Most common type – Tough and somewhat flexible – Reduces friction between bones – Found in synovial joints, rib tips, sternum, and trachea  Elastic cartilage – Supportive but bends easily – Found in external ear and epiglottis 98 © 2018 Pearson Education, Inc.  4-7 Supporting Connective Tissues  Fibrocartilage – Very durable and tough – Limits movement – Prevents bone-to-bone contact – Found around joints, between pubic bones, and between spinal vertebrae 99 © 2018 Pearson Education, Inc. Figure 4–15a Types of Cartilage. a Hyaline Cartilage LOCATIONS: Between tips of ribs and bones of sternum; covering bone surfaces at synovial joints; supporting larynx (voice box), trachea, and bronchi; forming part of nasal septum Chondrocytes FUNCTIONS: Provides stiff in lacunae but somewhat flexible support; reduces friction between Matrix bony surfaces LM × 500 Hyaline cartilage 100 © 2018 Pearson Education, Inc. Figure 4–15b Types of Cartilage. b Elastic Cartilage LOCATIONS: Auricle of external ear; epiglottis; auditory canal; cuneiform cartilages of larynx FUNCTIONS: Provides support, Chondrocytes but tolerates in lacunae distortion without damage and returns to original Elastic fibers shape in matrix LM × 358 Elastic cartilage 101 © 2018 Pearson Education, Inc. Figure 4–15c Types of Cartilage. c Fibrocartilage LOCATIONS: Pads within knee joint; between pubic bones of pelvis; intervertebral discs FUNCTIONS: Resists compression; Chondrocytes prevents bone- in lacunae to-bone contact; limits movement Fibrous matrix LM × 400 Fibrocartilage 102 © 2018 Pearson Education, Inc.  4-7 Supporting Connective Tissues  Cartilage growth – Interstitial growth Enlarges cartilage from within – Appositional growth Growth at outer surface of cartilage 103 © 2018 Pearson Education, Inc. Figure 4–16a The Growth of Cartilage. a Interstitial growth Matrix New matrix Chondrocyte Lacuna Chondrocyte undergoes division within a lacuna surrounded by As daughter cells secrete additional matrix, they cartilage matrix. move apart, expanding the cartilage from within. 104 © 2018 Pearson Education, Inc. Figure 4–16b The Growth of Cartilage. b Appositional growth Fibrous layer Fibroblast Dividing stem cell Perichondrium New matrix Chondroblasts Immature chondrocyte Older matrix Mature chondrocyte Cells of the inner layer of These immature chondroblasts As the matrix enlarges, more chondroblasts the perichondrium differentiate secrete new matrix. are incorporated; they are replaced by stem into chondroblasts. cell divisions in the perichondrium. 105 © 2018 Pearson Education, Inc.  4-7 Supporting Connective Tissues  Bone (osseous tissue) – For weight support – Calcified (made rigid by calcium salts) – Resists shattering (flexible collagen fibers) – Osteocytes (bone cells) lie in lacunae Arranged around central canals within matrix Small channels through matrix (canaliculi) allow for exchange of materials with blood – Periosteum covers bone Fibrous (outer) and cellular (inner) layers 106 © 2018 Pearson Education, Inc. Figure 4–17 Bone. Canaliculi Periosteum Osteocytes Fibrous layer in lacunae Matrix Cellular layer Osteon Central canal Blood vessels Osteon LM × 375 107 © 2018 Pearson Education, Inc.  4-8 Tissue Membranes  Tissue membranes – Physical barriers – Line or cover body surfaces – Consist of an epithelium supported by connective tissue 108 © 2018 Pearson Education, Inc.  4-8 Tissue Membranes  Four types of tissue membranes 1. Mucous membranes 2. Serous membranes 3. Cutaneous membrane 4. Synovial membranes 109 © 2018 Pearson Education, Inc.  4-8 Tissue Membranes  Mucous membranes (mucosae) – Line passageways that have external connections – In digestive, respiratory, urinary, and reproductive tracts – Epithelial surfaces must be moist To reduce friction To facilitate absorption or secretion – Lamina propria is areolar tissue in mucous membranes 110 © 2018 Pearson Education, Inc. Figure 4–18a Types of Membranes. Mucous secretion Epithelium Lamina propria (areolar tissue) a Mucous membranes are coated with the secretions of mucous glands. These membranes line most of the digestive and respiratory tracts and portions of the urinary and reproductive tracts. 111 © 2018 Pearson Education, Inc.  4-8 Tissue Membranes  Serous membranes – Line cavities that do not open to the outside – Thin but strong – Parietal portion lines inner surface of cavity – Visceral portion (serosa) covers the organs – Serous fluid reduces friction 112 © 2018 Pearson Education, Inc.  4-8 Tissue Membranes  Serous membranes 1. ​Peritoneum Lines peritoneal cavity Covers abdominal organs 2. ​Pleura Lines pleural cavities Covers lungs 3. ​Pericardium Lines pericardial cavity Covers heart 113 © 2018 Pearson Education, Inc. Figure 4–18b Types of Membranes. Serous fluid Mesothelium Areolar connective tissue b Serous membranes line the peritoneal, pleural, and pericardial cavities. 114 © 2018 Pearson Education, Inc.  4-8 Tissue Membranes  Cutaneous membrane – Skin that covers the body – Thick, relatively waterproof, and usually dry  Synovial membranes – Line synovial joint cavities – Movement stimulates production of synovial fluid for lubrication – Lack a true epithelium 115 © 2018 Pearson Education, Inc. Figure 4–18c Types of Membranes. Epithelium Areolar connective tissue Dense irregular connective tissue c The cutaneous membrane, or skin, covers the outer surface of the body. 116 © 2018 Pearson Education, Inc. Figure 4–18d Types of Membranes. Articular (hyaline) cartilage Synovial fluid Capsule Capillary Adipocytes Synovial membrane Areolar tissue Epithelium Bone d Synovial membranes line joint cavities and produce the synovial fluid within the joint. 117 © 2018 Pearson Education, Inc.  4-9 Muscle Tissue  Muscle tissue – Specialized for contraction – Three types of muscle tissue 1. Skeletal muscle – Large muscles responsible for body movement 2. Cardiac muscle – Found only in the heart 3. Smooth muscle – Found in walls of hollow, contracting organs 118 © 2018 Pearson Education, Inc.  4-9 Muscle Tissue  Skeletal muscle tissue – Consists of long, thin cells called muscle fibers – Cells do not divide – New fibers are produced by divisions of myosatellite cells – Striated voluntary muscle 119 © 2018 Pearson Education, Inc. Figure 4–19a Types of Muscle Tissue. a Skeletal Muscle Tissue Cells are long, cylindrical, striated, and multinucleate. LOCATIONS: Combined Striations with connective tissues and neural tissue in Nuclei skeletal muscles FUNCTIONS: Moves or stabilizes the position of the skeleton; guards Muscle entrances and exits to the fiber digestive, respiratory, and urinary tracts; generates heat; protects internal organs LM × 180 Skeletal muscle 120 © 2018 Pearson Education, Inc.  4-9 Muscle Tissue  Cardiac muscle tissue – Cells form branching networks connected at intercalated discs – Regulated by pacemaker cells – Striated involuntary muscle  Smooth muscle tissue – Cells are small and spindle shaped Can divide and regenerate – Nonstriated involuntary muscle 121 © 2018 Pearson Education, Inc. Figure 4–19b Types of Muscle Tissue. b Cardiac Muscle Tissue Cells are short, branched, Nuclei and striated, usually with a single nucleus; cells are interconnected by Cardiac intercalated discs. muscle LOCATION: Heart cells FUNCTIONS: Circulates Intercalated blood; maintains discs blood pressure Striations LM × 450 Cardiac muscle 122 © 2018 Pearson Education, Inc. Figure 4–19c Types of Muscle Tissue. c Smooth Muscle Tissue Cells are short, spindle shaped, and nonstriated, with a single, central nucleus. LOCATIONS: Found in Nuclei the walls of blood vessels and in digestive, respiratory, urinary, and reproductive organs FUNCTIONS: Moves food, urine, and reproductive Smooth tract secretions; controls muscle diameter of respiratory cells passageways; regulates diameter of blood vessels Smooth muscle LM × 235 123 © 2018 Pearson Education, Inc.  4-10 Nervous Tissue  Nervous tissue – Specialized for conducting electrical impulses – Concentrated in the brain and spinal cord  Types of cells in nervous tissue 1. ​Neurons 2. ​Neuroglia (supporting cells) 124 © 2018 Pearson Education, Inc.  4-10 Nervous Tissue  Parts of a neuron – Cell body Contains the nucleus and nucleolus – Dendrites Short branches extending from the cell body Receive incoming signals – Axon (nerve fiber) Long, thin extension of the cell body Carries outgoing electrical signals to their destination 125 © 2018 Pearson Education, Inc. Figure 4–20 Nervous Tissue (Part 1 of 3). Nuclei of neuroglia Cell body Axon Dendrites Nucleolus Nucleus LM × 600 126 © 2018 Pearson Education, Inc. Figure 4–20 Nervous Tissue (Part 2 of 3). NEUROGLIA (supporting cells) Maintain physical structure of tissues Repair tissue framework after injury Perform phagocytosis Provide nutrients to neurons Regulate the composition of the interstitial fluid surrounding neurons 127 © 2018 Pearson Education, Inc. Figure 4–20 Nervous Tissue (Part 3 of 3). Dendrites (contacted by other Contact with Axon (conducts other cells neurons) Microfibrils and information to microtubules other cells) Cell body (contains nucleus and major organelles) Nucleus Nucleolus Mitochondrion A representative neuron (sizes and shapes vary widely) 128 © 2018 Pearson Education, Inc.  4-11 Tissue Injuries and Repair  Tissues respond to injury in two stages 1. ​Inflammation (inflammatory response) 2. ​Regeneration to restore normal function 129 © 2018 Pearson Education, Inc.  4-11 Tissue Injuries and Repair  Inflammatory response – Can be triggered by Trauma (physical injury) Infection (the presence of pathogens) – Damaged cells release prostaglandins, proteins, and potassium ions – Damaged connective tissue activates mast cells 130 © 2018 Pearson Education, Inc.  4-11 Tissue Injuries and Repair  Process of inflammation – Lysosomes release enzymes that destroy the injured cells and attack surrounding tissues – Tissue destruction is called necrosis Begins several hours after injury  Necrotic tissues and cellular debris (pus) accumulate in the wound – Abscess—pus trapped in an enclosed area 131 © 2018 Pearson Education, Inc.  4-11 Tissue Injuries and Repair  The ability to regenerate varies among tissues – Epithelia, connective tissues (except cartilage), and smooth muscle regenerate well – Skeletal muscle, cardiac muscle, and nervous tissues regenerate poorly, if at all – Damaged cardiac muscle cells are replaced by fibrous tissue through fibrosis 132 © 2018 Pearson Education, Inc. Figure 4–21 Inflammation and Regeneration (Part 1 of 5). Mast Cell Activation When an injury damages connective tissue, mast cells release a variety of chemicals. This process, called mast cell Mast cell activation, stimulates inflammation. Histamine stimulates Exposure to Pathogens and Toxins Injured tissue contains an abnormal concentration of pathogens, toxins, wastes, and the chemicals from injured cells. When a tissue is injured, a general defense mechanism is activated. 133 © 2018 Pearson Education, Inc. Figure 4–21 Inflammation and Regeneration (Part 2 of 5). Mast Cell Activation When an injury damages connective tissue, mast cells release a variety of chemicals. This process, called mast cell Mast cell activation, stimulates inflammation. Histamine Heparin Prostaglandins INFLAMMATION Inflammation produces several familiar indications of injury. These indications are the so-called cardinal signs of inflammation: redness, heat (warmth), swelling, pain, and sometimes loss of function. Inflammation may also result from the presence of pathogens, such as harmful bacteria, within the tissues. The presence of these pathogens constitutes an infection. Increased Blood Flow Increased Vessel Permeability Pain In response to the Vessel dilation is accompanied by The abnormal conditions released chemicals, an increase in the permeability of within the tissue and the blood vessels dilate, the capillary walls. Plasma now chemicals released by mast increasing blood flow diffuses into the injured tissue, so cells stimulate nerve through the damaged the area becomes swollen. endings that produce the tissue. sensation of pain. PAIN 134 © 2018 Pearson Education, Inc. Figure 4–21 Inflammation and Regeneration (Part 3 of 5). INFLAMMATION Inflammation produces several familiar indications of injury. These indications are the so-called cardinal signs of inflammation: redness, heat (warmth), swelling, pain, and sometimes loss of function. Inflammation may also result from the presence of pathogens, such as harmful bacteria, within the tissues. The presence of these pathogens constitutes an infection. Increased Blood Flow Increased Vessel Permeability Pain In response to the Vessel dilation is accompanied by The abnormal conditions released chemicals, an increase in the permeability of within the tissue and the blood vessels dilate, the capillary walls. Plasma now chemicals released by increasing blood flow diffuses into the injured tissue, so mast cells stimulate nerve through the damaged the area becomes swollen. endings that produce the tissue. sensation of pain. PAIN Increased Local Increased Oxygen Increased Removal of Toxins Temperature and Nutrients Phagocytosis and Wastes The increased Vessel dilation, Phagocytes in Enhanced circulation blood flow and increased blood the tissue are carries away toxins and permeability flow, and increased activated, and wastes, distributing cause the tissue vessel permeability they begin them to the kidneys for to become warm result in enhanced engulfing tissue excretion, or to the liver and red. delivery of oxygen debris and for inactivation. and nutrients. pathogens. O2 Toxins and wastes 135 © 2018 Pearson Education, Inc.  4-12 Aging, Regeneration, and Cancer  Aging and tissue structure – Speed and effectiveness of tissue regeneration decrease with age, due to Slowing of repair and maintenance activities Hormonal alterations Reduced physical activity 136 © 2018 Pearson Education, Inc.  4-12 Aging, Regeneration, and Cancer  Effects of aging – Chemical and structural tissue changes Thinner epithelia Fragile connective tissues Increased bruising Brittle bones Cardiovascular disease Mental deterioration 137 © 2018 Pearson Education, Inc.  4-12 Aging, Regeneration, and Cancer  Aging and cancer incidence – Cancer rates increase with age Twenty-five percent of all people in the United States develop cancer Cancer is the second leading cause of death in the United States Most cancers are caused by chemical exposure or environmental factors – Forty percent of cases are caused by cigarette smoke 138 © 2018 Pearson Education, Inc.