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Human Anatomy and Physiology: Unit 2 Part 2 • Unit 2 Part 2: Tissues • Chapter 4 • © 2013 Pearson Education, Inc. Chapter 4 Learning Targets • 4-1 • Identify the body's four basic types of tissues and describe their roles. • 4-2 • Describe the characteristics and functions of epithelial cells. • 4-3 • Describe the relationship between form and function for each type of epithelium. • 4-4 • Compare the structures and functions of the various types of connective tissues. © 2013 Pearson Education, Inc. Chapter 4 Learning Targets • 4-5 • Explain how epithelial and connective tissues combine to form four types of tissue membranes, and specify the functions of each. • 4-6 • Describe the three types of muscle tissue and the special structural features of each. • 4-7 • Discuss the basic structure and role of neural tissue. • 4-8 • Explain how injuries affect the tissues of the body. • 4-9 • Describe how aging affects the tissues of the body. © 2013 Pearson Education, Inc. Tissues (4-1) • Collections of cells and cell products that perform specific, limited functions • Histology • • The study of tissues Four types of tissues 1. Epithelial 2. Connective 3. Muscle 4. Neural © 2013 Pearson Education, Inc. Figure 4-1 An Orientation to the Tissues of the Body. CELLS That secrete and regulate EXTRACELLULAR MATERIAL AND FLUIDS Combine to form TISSUES with special functions Combine to form ORGANS with multiple functions Interact in ORGAN SYSTEMS Chapters 5–20 © 2013 Pearson Education, Inc. EPITHELIAL TISSUE • Covers exposed surfaces • Lines internal passageways and chambers • Produces glandular secretions CONNECTIVE TISSUE • Fills internal spaces • Provides structural support • Stores energy MUSCLE TISSUE • Contracts to produce active movement NEURAL TISSUE • Conducts electrical Impulses • Carries information Checkpoint (4-1) 1. Define histology. 2. List the four basic types of tissues in the body. © 2013 Pearson Education, Inc. Epithelial Tissue (4-2) • Covers body surfaces • Lines cavities • Lines tubular structures • Serves essential functions © 2013 Pearson Education, Inc. Functions of Epithelia (4-2) • Provide physical protection • Control permeability • Provide sensation • Produce specialized secretions (glandular epithelium) • Exocrine glands- secretions are discharged outside the epithelium (ex. Perspiration from skin glands) • Endocrine glands- secretions are discharged within the tissue fluid and blood (ex. Hormones) © 2013 Pearson Education, Inc. Figure 4-3 The Surfaces of Epithelial Cells. Cilia Microvilli Apical surface Golgi apparatus Nucleus Mitochondria Basement membrane © 2013 Pearson Education, Inc. Epithelial Renewal and Repair (4-2) • Epithelia are replaced by mitosis • Cell division of stem cells (germinative cells) • Occurs near basement membrane © 2013 Pearson Education, Inc. Checkpoint (4-2) 3. List five important characteristics of epithelial tissue. 4. Identify four essential functions of epithelial tissue. 5. Identify the three main types of epithelial cell junctions. 6. What physiological functions are enhanced by the presence of microvilli or cilia on epithelial cells? © 2013 Pearson Education, Inc. Classification of Epithelia (4-3) • Combines a cell shape with the number of layers of cells • Example: • Simple (one layer) cuboidal (square shape) © 2013 Pearson Education, Inc. Cell Layers and Cell Shapes (4-3) • Classification is based on layers • Simple epithelium: single layer of cells • Stratified epithelium: several layers of cells • Classification is based on shape • Squamous epithelia: thin and flat • Cuboidal epithelia: square shaped • Columnar epithelia: tall, slender rectangles © 2013 Pearson Education, Inc. Table 4-1 Classifying Epithelia © 2013 Pearson Education, Inc. Cell Layers and Cell Shapes (4-3) • Simple squamous epithelium: • Location: kidneys, lungs, heart, lining of ventral body cavity • Function: absorption, secretion , reduce friction • Simple coboidal epithelium: • Location: glands, ducts, kidneys, and thyroid gland • Function: some protection, secretion, and absorption • Simple columnar epithelium • Location: stomach, intestines, gall bladder, uterus, and kidneys • Function: some protection, secretion, absorption © 2013 Pearson Education, Inc. Cell Layers and Cell Shapes (4-3) • Stratified squamous epithelium: • Location: skin, lining of the mouth, tongue, esophagus, and anus • Function: line areas where mechanical stresses are severe • Stratified cuboidal epithelium : • Location: along the ducts of sweat glands and mammary glands *very rare* • Function: secretion Stratified columnar epithelium: • Location: along portions of the pharynx, epiglottis, anus, and urethra *very rare* • Function: protection © 2013 Pearson Education, Inc. Figure 4-4a Simple Epithelia. Simple Squamous Epithelium LOCATIONS: Epithelia lining ventral body cavities; lining heart and blood vessels; portions of kidney tubules (thin sections of nephron loops); inner lining of cornea; alveoli (air sacs) of lungs FUNCTIONS: Reduces friction; controls vessel permeability; performs absorption and secretion Cytoplasm Nucleus Connective tissue Lining of peritoneal cavity © 2013 Pearson Education, Inc. LM x 238 Figure 4-4b Simple Epithelia. Simple Cuboidal Epithelium LOCATIONS: Glands; ducts; portions of kidney tubules; thyroid gland Connective tissue Nucleus FUNCTIONS: Limited protection, secretion, absorption Kidney tubule © 2013 Pearson Education, Inc. Cuboidal cells Basement membrane LM x 650 Figure 4-4c Simple Epithelia. Simple Columnar Epithelium LOCATIONS: Lining of stomach, intestine, gallbladder, uterine tubes, and collecting ducts of kidneys Microvilli Cytoplasm FUNCTIONS: Protection, secretion, absorption Nucleus Intestinal lining © 2013 Pearson Education, Inc. Basement membrane Connective tissue LM x 350 Figure 4-5a Stratified Epithelia. Stratified Squamous Epithelium LOCATIONS: Surface of skin; lining of mouth, throat, esophagus, rectum, anus, and vagina FUNCTIONS: Provides physical protection against abrasion, pathogens, and chemical attack © 2013 Pearson Education, Inc. Squamous superficial cells Stem cells Basement membrane Connective Surface of tongue tissue LM x 310 Figure 4-5b Stratified Epithelia. Pseudostratified Ciliated Columnar Epithelium LOCATIONS: Lining of nasal cavity, trachea, and bronchi; portions of male reproductive tract Cilia Cytoplasm Nuclei FUNCTIONS: Protection, secretion, move mucus with cilia Trachea © 2013 Pearson Education, Inc. Basement membrane Connective tissue LM x 350 Figure 4-5c Stratified Epithelia. Transitional Epithelium LOCATIONS: Urinary bladder; renal pelvis; ureters Epithelium (relaxed) FUNCTIONS: Permits expansion and recoil after stretching Basement membrane Connective tissue and Empty bladder smooth muscle layers LM x 400 Epithelium (stretched) Basement membrane Connective tissue and smooth muscle layers LM x 400 Full bladder Urinary bladder © 2013 Pearson Education, Inc. Connective Tissue (4-4) • Provides a protective structural framework for other tissue types • Three basic components 1. Specialized cells 2. Solid extracellular protein fibers 3. Fluid extracellular ground substance © 2013 Pearson Education, Inc. Characteristics of Connective Tissue (4-4) • The extracellular components of connective tissues (fibers and ground substance) make up the matrix • Majority of tissue volume • Determines specialized function © 2013 Pearson Education, Inc. Functions of Connective Tissue (4-4) • Support and protection • Transportation of materials • Storage of energy reserves • Defense of the body © 2013 Pearson Education, Inc. Figure 4-7 Major Types of Connective Tissue. CONNECTIVE TISSUES CONNECTIVE TISSUE PROPER FLUID CONNECTIVE TISSUES SUPPORTING CONNECTIVE TISSUES LOOSE DENSE BLOOD LYMPH CARTILAGE BONE Fibers create loose, open framework Fibers densely packed Flows within cardiovascular system Flows within lymphatic system Solid, rubbery matrix Solid, crystalline matrix © 2013 Pearson Education, Inc. Three Major Types of Connective Tissue (4-4) 1. Connective tissue proper 2. Fluid connective tissues 3. Supporting connective tissues © 2013 Pearson Education, Inc. • Connective tissue proper • Consists of: • Many cell types • Matrix + ground substance • Examples: • Skin, fatty tissue, tendons, and ligaments © 2013 Pearson Education, Inc. • Fluid connective tissue • Consists of: • Distinct cells in a matrix of water ground substance containing proteins • Examples: • Blood and lymph © 2013 Pearson Education, Inc. • Supporting connective tissue • Consists of: • Less diverse cell population • matrix of dense ground substance and closely packed fibers • Examples: • Cartilage and bone © 2013 Pearson Education, Inc. © 2013 Pearson Education, Inc. © 2013 Pearson Education, Inc. Ground Substance (4-4) • Clear, colorless, and viscous • Fills spaces between cells and slows pathogen movement © 2013 Pearson Education, Inc. Types of Connective Tissue Proper (4-4) • Loose connective tissue • "Packing materials" of the body • More ground substance, fewer fibers • Example: fat (adipose tissue) • Dense connective tissue • Tough, strong, and durable • More fibers, less ground substance • Example: tendons © 2013 Pearson Education, Inc. Figure 4-8 Cells and Fibers of Connective Tissue Proper. Reticular fibers Fixed macrophage Antibody producing cell Blood in vessel Mast cell Elastic fibers Free macrophage Collagen fibers Fibroblast Stem cell Adipocytes (fat cells) Ground substance © 2013 Pearson Education, Inc. White blood cell Figure 4-9a Loose Connective Tissues. Areolar Tissue LOCATIONS: Beneath dermis of skin, digestive tract, respiratory and urinary tracts; between muscles; around blood vessels, nerves, and around joints FUNCTIONS: Cushions organs; provides support but permits independent movement; phagocytic cells provide defense against pathogens © 2013 Pearson Education, Inc. Collagen fibers Fat cell Mast cell Fibroblasts Elastic fibers Macrophage Areolar tissue LM x 400 Figure 4-9b Loose Connective Tissues. Adipose Tissue LOCATIONS: Deep to the skin, especially at sides, buttocks, breasts; padding around eyes and kidneys Adipocytes FUNCTIONS: Provides padding and cushions shocks; insulates (reduces heat loss); stores energy Adipose tissue © 2013 Pearson Education, Inc. LM x 300 Figure 4-9c Loose Connective Tissues. Reticular Tissue LOCATIONS: Liver, kidney, spleen, lymph nodes, and bone marrow FUNCTIONS: Provides supporting framework Reticular tissue from liver © 2013 Pearson Education, Inc. Reticular fibers Reticular tissue LM x 375 Figure 4-10a Dense Connective Tissues. Dense Regular Connective Tissue LOCATIONS: Between skeletal muscles and skeleton (tendons and aponeuroses); between bones or stabilizing positions of internal organs (ligaments); covering skeletal muscles; deep fasciae FUNCTIONS: Provides firm attachment; conducts pull of muscles; reduces friction between muscles; stabilizes relative positions of bones © 2013 Pearson Education, Inc. Collagen fibers Fibroblast nuclei Tendon LM x 440 Figure 4-10b Dense Connective Tissues. Dense Irregular Connective Tissue LOCATIONS: Capsules of visceral organs; periostea and perichondria; nerve and muscle sheaths; deep dermis of the skin FUNCTIONS: Provides strength to resist forces applied from many directions; helps prevent overexpansion of organs such as the urinary bladder Collagen fiber bundles Deep dermis © 2013 Pearson Education, Inc. LM x 111 Fluid Connective Tissues (4-4) • Blood and lymph • Watery matrix of dissolved proteins • Carry specific cell types (formed elements) • Formed elements of blood • Red blood cells • White blood cells • Platelets © 2013 Pearson Education, Inc. Supporting Connective Tissues (4-4) • Cartilage • Gel-type ground substance • For shock absorption and protection • Bone • Calcified (made rigid by calcium salts, minerals) • For weight support © 2013 Pearson Education, Inc. Table 4-3 A Comparison of Cartilage and Bone © 2013 Pearson Education, Inc. Checkpoint (4-4) 12. Identify several functions of connective tissues. 13. List the three types of connective tissues. 14. Which type of connective tissue contains primarily triglycerides? 15. Lack of vitamin C in the diet interferes with the ability of fibroblasts to produce collagen. What effect might this interference have on connective tissue? 16. Which two types of connective tissue have a fluid matrix? © 2013 Pearson Education, Inc. Checkpoint (4-4) 17. Identify the two types of supporting connective tissue. 18. Why does cartilage heal slower than bone? © 2013 Pearson Education, Inc. Tissue Membranes (4-5) • Membranes • Are physical barriers • Line or cover portions of the body • Consist of: • An epithelium • Supported by connective tissues © 2013 Pearson Education, Inc. Four Types of Tissue Membranes (4-5) 1. Mucous membranes 2. Serous membranes 3. Cutaneous membrane 4. Synovial membranes © 2013 Pearson Education, Inc. Figure 4-13 Tissue Membranes. Mucous membranes are coated with the secretions of mucous glands. These membranes line the digestive, respiratory, urinary, and reproductive tracts. Mucous secretion Serous membranes line the ventral body cavities (the peritoneal, pleural, and pericardial cavities). Serous fluid The cutaneous membrane, or skin, covers the outer surface of the body. Epithelium Lamina propria (areolar tissue) Epithelium Areolar tissue Epithelium Areolar tissue Dense irregular connective tissue Synovial membranes line joint cavities and produce the fluid within the joint. Articular (hyaline) cartilage Synovial fluid Capsule Capillary Adipocytes Areolar tissue Epithelium Bone © 2013 Pearson Education, Inc. Synovial membrane Mucous Membranes (4-5) • Also known as 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 and excretion • Lamina propria • Made of areolar tissue © 2013 Pearson Education, Inc. Figure 4-13a Tissue Membranes. © 2013 Pearson Education, Inc. Mucous membranes are coated with the secretions of mucous glands. These membranes line the digestive, respiratory, urinary, and reproductive tracts. Mucous secretion Epithelium Lamina propria (areolar tissue) Serous Membranes (4-5) • Line cavities not open to the outside • Are thin but strong • Have fluid transudate to reduce friction • Have a parietal portion covering the cavity • Have a visceral portion (serosa) covering the organs © 2013 Pearson Education, Inc. Three Serous Membranes (4-5) 1. Pleura • Lines pleural cavities • Covers lungs 2. Peritoneum • Lines peritoneal cavity • Covers abdominal organs 3. Pericardium • Lines pericardial cavity • Covers heart © 2013 Pearson Education, Inc. Figure 4-13b Tissue Membranes. Serous membranes line the ventral body cavities (the peritoneal, pleural, and pericardial cavities). © 2013 Pearson Education, Inc. Serous fluid Epithelium Areolar tissue The Cutaneous Membrane (4-5) • Is skin • Covers the surface of the body • Thick, waterproof, and dry © 2013 Pearson Education, Inc. Figure 4-13c Tissue Membranes. The cutaneous membrane, or skin, covers the outer surface of the body. Epithelium Areolar tissue Dense irregular connective tissue © 2013 Pearson Education, Inc. Synovial Membranes (4-5) • Line moving, articulating joint cavities • Produce synovial fluid (lubricant) • Protect the ends of bones • Lack a true epithelium © 2013 Pearson Education, Inc. Figure 4-13d Tissue Membranes. Synovial membranes line joint cavities and produce the fluid within the joint. Articular (hyaline) cartilage Synovial fluid Capsule Capillary Adipocytes Areolar tissue Synovial Epithelium membrane Bone © 2013 Pearson Education, Inc. Checkpoint (4-5) 19. Identify the four types of tissue membranes found in the body. 20. How does a plasma (cell) membrane differ from a tissue membrane? 21. What is the function of fluids produced by serous membranes? 22. The lining of the nasal cavity is normally moist, contains numerous mucous cells, and rests on a layer of areolar tissue. Which type of membrane is this? © 2013 Pearson Education, Inc. Three Types of Muscle Tissue (4-6) 1. Skeletal muscle tissue • Large body muscles responsible for movement 2. Cardiac muscle tissue • Found only in the heart 3. Smooth muscle tissue • Found in walls of blood vessels • Found around hollow organs such as the urinary bladder • Around the respiratory, digestive, and reproductive tracts © 2013 Pearson Education, Inc. Functions of Muscle Tissue (4-6) • Specialized for contraction • Produces all body movement © 2013 Pearson Education, Inc. Figure 4-14a Muscle Tissue. Skeletal Muscle Tissue Cells are long, cylindrical, striated, and multinucleate. LOCATIONS: Combined with connective tissues and neural tissue in skeletal muscles FUNCTIONS: Moves or stabilizes the position of the skeleton; guards entrances and exits to the digestive, respiratory, and urinary tracts; generates heat; protects internal organs © 2013 Pearson Education, Inc. Nuclei Muscle fiber Striations Skeletal muscle LM x 180 Figure 4-14b Muscle Tissue. Cardiac Muscle Tissue Nucleus Cells are short, branched, and striated, usually with a single nucleus; cells are interconnected by intercalated discs. Cardiac muscle cells LOCATION: Heart FUNCTIONS: Circulates blood; maintains blood (hydrostatic) pressure Intercalated discs Striations Cardiac muscle © 2013 Pearson Education, Inc. LM x 450 Figure 4-14c Muscle Tissue. Smooth Muscle Tissue Cells are short, spindle-shaped, and nonstriated, with a single, central nucleus. LOCATIONS: Found in the walls of blood vessels and in digestive, respiratory, urinary, and reproductive organs FUNCTIONS: Moves food, urine, and reproductive tract secretions; controls diameter of respiratory passageways; regulates diameter of blood vessels © 2013 Pearson Education, Inc. Nucleus Smooth muscle cell Smooth muscle LM x 235 Checkpoint (4-6) 23. Identify the three types of muscle tissue in the body. 24. Voluntary control is restricted to which type of muscle tissue? 25. Which type of muscle tissue has small, tapering cells with single nuclei and no obvious striations? © 2013 Pearson Education, Inc. Neural Tissue (4-7) • Also called nervous or nerve tissue • Specialized for conducting electrical impulses • Rapidly senses internal or external environment • Processes information and controls responses © 2013 Pearson Education, Inc. Neural Tissue (4-7) • Concentrated in the central nervous system • Brain • Spinal cord © 2013 Pearson Education, Inc. Two Kinds of Neural Cells (4-7) 1. Neurons • Nerve cells • Perform electrical communication 2. Neuroglia • Supporting cells • Repair and supply nutrients to neurons © 2013 Pearson Education, Inc. Cell Parts of a Neuron (4-7) • 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 © 2013 Pearson Education, Inc. Figure 4-15 Neural Tissue. Brain Axon terminals Spinal cord Nuclei of neuroglia Cell body Cell body Nucleus of neuron Axon Dendrites Axon LM x 600 Neuron © 2013 Pearson Education, Inc. Photomicrograph of neuron cell body Checkpoint (4-7) 26. A tissue contains irregularly shaped cells with many projections, including some several centimeters long. These are probably which type of cell? 27. Why are both skeletal muscle cells and axons also called fibers? © 2013 Pearson Education, Inc. Tissue Injuries and Repair (4-8) • Tissues respond to injuries to maintain homeostasis • Cells restore homeostasis with two processes 1. Inflammation 2. Regeneration © 2013 Pearson Education, Inc. Inflammation (4-8) • Inflammatory response • The tissue's first response to injury • Signs and symptoms include: • Swelling • Heat • Redness • Pain © 2013 Pearson Education, Inc. Inflammatory Response (4-8) • Can be triggered by: • Trauma (physical injury) • Infection (the presence of harmful pathogens) © 2013 Pearson Education, Inc. Checkpoint (4-8) 28. Identify the two phases in the response to tissue injury. 29. What signs and symptoms are associated with inflammation? 30. What is fibrosis? © 2013 Pearson Education, Inc. Aging Tissue (4-9) • With age: • Rate of tissue repair declines • Cancer rates increase © 2013 Pearson Education, Inc. Aging and Tissue Structure (4-9) • Speed and efficiency of tissue repair decrease with age due to: • Slower rate of energy consumption (metabolism) • Hormonal alterations • Reduced physical activity © 2013 Pearson Education, Inc. Aging and Cancer Incidence (4-9) • Cancer rates increase with age • 1 in 4 people in the United States develops cancer • Cancer is the #2 cause of death in the United States • Environmental chemicals and cigarette smoke cause cancer © 2013 Pearson Education, Inc. Checkpoint (4-9) 31. Identify some age-related factors that affect tissue repair and structure. © 2013 Pearson Education, Inc.