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The Body Tissues © 2012 Pearson Education, Inc. • A. Define cell differentiation and explain its importance. • B. Describe stem cells and explain their importance. • C. Review tissue types. • D. Epithelial tissue • 1.Describe important characteristics of epithelial tissue. • 2.Describe essential functions of epithelial tissue. • 3.Describe structural specializations of epithelial tissue. • 4.Glandular epithlelia • a.Distinguish between merocrine, apocrine and holocrine secretion. • b.Distinguish between serous and mucous secretions. • 5.Define exfoliative cytology and provide examples. • E.Connective tissue • 1.Define fascia and describe its location and functions. • F.Membranes • 1.Describe the basic structure of membranes. • 2.Describe the 4 types of membranes, their functions and locations. © 2012 Pearson Education, Inc. 4-1 Four Types of Tissue • Tissue • Are collections of cells and cell products that perform specific, limited functions • Four types of tissue 1. Epithelial tissue 2. Connective tissue 3. Muscle tissue 4. Neural tissue © 2012 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 © 2012 Pearson Education, Inc. • Muscle Tissue • Specialized for contraction • Skeletal muscle, heart muscle, and walls of hollow organs • Neural Tissue • Carries electrical signals from one part of the body to another 4-2 Epithelial Tissue • Characteristics of Epithelia • Cellularity (cell junctions) • Polarity (apical and basal surfaces) • Attachment (basement membrane or basal lamina) • Avascularity • Regeneration © 2012 Pearson Education, Inc. Figure 4-1 The Polarity of Epithelial Cells Cilia Microvilli Apical surface Golgi apparatus Nucleus Mitochondria Basement membrane Basolateral surfaces © 2012 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 (glandular epithelium) © 2012 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 messengers) • Polarity 1. Apical surfaces • Microvilli increase absorption or secretion • Cilia (ciliated epithelium) move fluid 2. Basolateral surfaces © 2012 Pearson Education, Inc. 4-2 Epithelial Tissue • Maintaining the Integrity of Epithelia 1. Intercellular connections 2. Attachment to the basement membrane 3. Epithelial maintenance and repair © 2012 Pearson Education, Inc. 4-2 Epithelial Tissue • Epithelial Maintenance and Repair • Epithelia are replaced by division of germinative cells (stem cells) • Near basement membrane © 2012 Pearson Education, Inc. 4-3 Classification of Epithelia • Singular = Epithelium; Plural = Epithelia • Classes of Epithelia 1. Based on shape • Squamous epithelia — thin and flat • Cuboidal epithelia — square shaped • Columnar epithelia — tall, slender rectangles 2. Based on layers • Simple epithelium — single layer of cells • Stratified epithelium — several layers of cells © 2012 Pearson Education, Inc. 4-3 Classification of Epithelia • Simple squamous epithelium • Absorption and diffusion • Mesothelium: Lines body cavities • Endothelium: Lines heart and blood vessels © 2012 Pearson Education, Inc. 4-3 Classification of Epithelia • Glandular Epithelia • Endocrine glands • Release hormones • Into interstitial fluid • No ducts • Exocrine glands • Produce secretions • Onto epithelial surfaces • Through ducts © 2012 Pearson Education, Inc. 4-3 Classification of Epithelia--Modes of Secretion • Merocrine Secretion • Produced in Golgi apparatus • Released by vesicles (exocytosis) • For example, sweat glands • Apocrine Secretion • Produced in Golgi apparatus • Released by shedding cytoplasm • For example, mammary glands © 2012 Pearson Education, Inc. 4-3 Classification of Epithelia • Holocrine Secretion • Released by cells bursting, killing gland cells • Gland cells replaced by stem cells • For example, sebaceous glands © 2012 Pearson Education, Inc. Figure 4-6 Modes of Glandular Secretion Secretory vesicle Golgi apparatus Nucleus TEM 3039 Salivary gland Mammary gland Breaks down Golgi apparatus Secretion Regrowth Hair Sebaceous gland Cells burst, releasing cytoplasmic contents Hair follicle Cells produce secretion, increasing in size Cell division replaces lost cells Stem cell © 2012 Pearson Education, Inc. 4-3 Classification of Epithelia • Glandular Epithelia • Types of Secretions • Serous glands • Watery secretions • Mucous glands • Secrete mucins • Mixed exocrine glands • Both serous and mucous © 2012 Pearson Education, Inc. 4-4 Connective Tissue Characteristics of Connective Tissue 1. Specialized cells 2. Extracellular protein fibers 3. Fluid extracellular ground substance • The Extracellular Components of Connective Tissue (Fibers and Ground Substance) • Make up the matrix • Majority of tissue volume\Determines specialized function © 2012 Pearson Education, Inc. 4-4 Connective Tissue • Functions of Connective Tissue • 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 in the form of triglycerides • Defending the body from invading microorganisms © 2012 Pearson Education, Inc. 4-6 Membranes • Four Types of Membranes 1. Mucous membranes 2. Serous membranes 3. Cutaneous membrane 4. Synovial membranes • Membranes • Physical barriers • Line or cover portions of the body • Consist of: • An epithelium • Supported by connective tissue © 2012 Pearson Education, Inc. 4-6 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 and excretion • Lamina propria • Is areolar tissue © 2012 Pearson Education, Inc. Figure 4-16a Membranes Mucous secretion Epithelium Lamina propria (areolar tissue) Mucous membranes are coated with the secretions of mucous glands. These membranes line the digestive, respiratory, urinary, and reproductive tracts. © 2012 Pearson Education, Inc. 4-6 Membranes • Serous Membranes • 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 © 2012 Pearson Education, Inc. 4-6 Membranes • Three Serous Membranes 1. Pleura • Lines pleural cavities • Covers lungs 2. Peritoneum • Lines peritoneal cavity • Covers abdominal organs 3. Pericardium • Lines pericardial cavity • Covers heart © 2012 Pearson Education, Inc. Figure 4-16b Membranes Transudate Mesothelium Areolar tissue Serous membranes line the ventral body cavities (the peritoneal, pleural, and pericardial cavities). © 2012 Pearson Education, Inc. 4-6 Membranes • Cutaneous Membrane • Is skin, surface of the body • Thick, waterproof, and dry • Synovial Membranes • Line moving, articulating joint cavities • Produce synovial fluid (lubricant) • Protect the ends of bones • Lack a true epithelium © 2012 Pearson Education, Inc. Figure 4-16c Membranes Epithelium Areolar tissue Dense irregular connective tissue The cutaneous membrane, or skin, covers the outer surface of the body. © 2012 Pearson Education, Inc. Figure 4-16d Membranes Articular (hyaline) tissue Synovial fluid Capsule Capillary Adipocytes Areolar tissue Epithelium Synovial membrane Bone Synovial membranes line joint cavities and produce the fluid within the joint. © 2012 Pearson Education, Inc. 4-7 Internal Framework of the Body • 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 form = fascia • The body’s framework of connective tissue • Layers and wrappings that support or surround organs © 2012 Pearson Education, Inc. 4-7 Internal Framework of the Body • Three Types of Fasciae 1. Superficial fascia 2. Deep fascia 3. Subserous fascia © 2012 Pearson Education, Inc. Figure 4-17 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 • Forms a strong, fibrous internal framework • Dense connective tissue • Bound to capsules, tendons, and ligaments Subserous Fascia Rib • Between serous membranes and deep fascia • Areolar tissue Serous membrane Cutaneous membrane © 2012 Pearson Education, Inc. 4-10 Tissue Injuries and Repair • Tissues Respond to Injuries • To maintain homeostasis • Cells restore homeostasis with two processes 1. Inflammation 2. Regeneration © 2012 Pearson Education, Inc. 4-10 Tissue Injuries and Repair • Inflammation = Inflammatory Response • The tissue’s first response to injury • Signs and symptoms of the inflammatory response include: • Swelling • Redness • Heat • Pain © 2012 Pearson Education, Inc. 4-10 Tissue Injuries and Repair • Inflammatory Response • Can be triggered by: • Trauma (physical injury) • Infection (the presence of harmful pathogens) © 2012 Pearson Education, Inc.