The Body Tissues

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.

4-1 Four Types of Tissue Tissue Are collections of cells and cell products that perform specific, limited functions Four types of tissue Epithelial tissue Connective tissue Muscle tissue Neural tissue

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 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

Figure 4-1 The Polarity of Epithelial Cells Cilia Microvilli Apical surface Golgi apparatus Nucleus Mitochondria Basement membrane Basolateral surfaces 6

4-2 Epithelial Tissue Functions of Epithelial Tissue Provide Physical Protection Control Permeability Provide Sensation Produce Specialized Secretions (glandular epithelium)

4-2 Epithelial Tissue Specializations of Epithelial Cells Polarity Move fluids over the epithelium (protection) Move fluids through the epithelium (permeability) Produce secretions (protection and messengers) Polarity Apical surfaces Microvilli increase absorption or secretion Cilia (ciliated epithelium) move fluid Basolateral surfaces

4-2 Epithelial Tissue Maintaining the Integrity of Epithelia Intercellular connections Attachment to the basement membrane Epithelial maintenance and repair

4-2 Epithelial Tissue Epithelial Maintenance and Repair Epithelia are replaced by division of germinative cells (stem cells) Near basement membrane

4-3 Classification of Epithelia Singular = Epithelium; Plural = Epithelia Classes of Epithelia Based on shape Squamous epithelia — thin and flat Cuboidal epithelia — square shaped Columnar epithelia — tall, slender rectangles Based on layers Simple epithelium — single layer of cells Stratified epithelium — several layers of cells

4-3 Classification of Epithelia Simple squamous epithelium Absorption and diffusion Mesothelium: Lines body cavities Endothelium: Lines heart and blood vessels

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

4-3 Classification of Epithelia--Modes of Secretion Merocrine Secretion Produced in Golgi apparatus Released by vesicles (exocytosis) For example, sweat glands Apocrine Secretion Released by shedding cytoplasm For example, mammary glands

4-3 Classification of Epithelia Holocrine Secretion Released by cells bursting, killing gland cells Gland cells replaced by stem cells For example, sebaceous glands

Figure 4-6 Modes of Glandular Secretion Secretory vesicle Golgi apparatus Nucleus TEM  3039 Salivary gland Breaks down Mammary gland 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 16

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

4-4 Connective Tissue Characteristics of Connective Tissue Specialized cells Extracellular protein fibers 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

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

4-6 Membranes Four Types of Membranes Membranes Physical barriers Mucous membranes Serous membranes Cutaneous membrane Synovial membranes Membranes Physical barriers Line or cover portions of the body Consist of: An epithelium Supported by connective tissue

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

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. 22

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

4-6 Membranes Three Serous Membranes Pleura Peritoneum Pericardium Lines pleural cavities Covers lungs Peritoneum Lines peritoneal cavity Covers abdominal organs Pericardium Lines pericardial cavity Covers heart

Figure 4-16b Membranes Transudate Mesothelium Areolar tissue Serous membranes line the ventral body cavities (the peritoneal, pleural, and pericardial cavities). 25

4-6 Membranes Cutaneous Membrane Synovial Membranes 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

The cutaneous membrane, or skin, covers the outer surface of the body. Figure 4-16c Membranes Epithelium Areolar tissue Dense irregular connective tissue The cutaneous membrane, or skin, covers the outer surface of the body. 27

Figure 4-16d Membranes Articular (hyaline) tissue Synovial fluid Capsule Capillary Adipocytes Areolar tissue Synovial membrane Epithelium Bone Synovial membranes line joint cavities and produce the fluid within the joint. 28

4-7 Internal Framework of the Body Connective Tissues Provide strength and stability Maintain positions of internal organs 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

4-7 Internal Framework of the Body Three Types of Fasciae Superficial fascia Deep fascia Subserous fascia

Connective Tissue Framework of Body 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 • Between serous membranes and deep fascia • Areolar tissue Rib Serous membrane Cutaneous membrane 31

4-10 Tissue Injuries and Repair Tissues Respond to Injuries To maintain homeostasis Cells restore homeostasis with two processes Inflammation Regeneration

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

4-10 Tissue Injuries and Repair Inflammatory Response Can be triggered by: Trauma (physical injury) Infection (the presence of harmful pathogens)