Week 4 - Tissues

Page 1: Introduction

• Chapter Title: The Human Tissues

• Subject: Anatomy & Physiology

• Edition: Tenth Edition by Kenneth S. Saladin

• Publisher: McGraw Hill LLC, © All rights reserved.

Page 2: Overview of Tissue Types

• Four Broad Categories of Tissues:

  • Epithelial Tissue: Covers body surfaces, lines cavities.

  • Connective Tissue: Supports and binds other tissues and organs.

  • Nervous Tissue: Transmits impulses and processes information.

  • Muscular Tissue: Responsible for body movement.

• Organ: Structure with discrete boundaries made up of two or more tissue types.

• Histology: Study of tissues and their organization into organs.

Page 3: Learning Outcomes on Tissues

• Expected Learning Outcomes:

  • Identify the four primary classes of adult tissues.

Page 4: Understanding Tissue Classes

• Definition of Tissue: Group of similar cells and products working together for specific roles.

• Differences Among Primary Tissues:

  • Types and functions of cells.

  • Characteristics of the matrix (extracellular material).

  • Amount of space taken by cells vs. matrix.

• Matrix Components:

  • Fibrous proteins and ground substance (water, gases, nutrients).

  • Also known as tissue fluid, extracellular fluid (ECF), interstitial fluid.

Page 5: Planes of Section

• Types of Section:

  • (a) Longitudinal sections.

  • (b) Cross sections.

  • (c) Oblique sections.

Page 6: Epithelial Tissue Learning Goals

• Expected Learning Outcomes:

  • Describe distinguishing properties of epithelium.

  • Classify eight types of epithelium by location in the body.

  • Explain structural-functional relationships in epithelial differences.

  • Visually recognize each epithelial type from specimens or photographs.

Page 7: Characteristics of Epithelial Tissue

• Definition: Sheet of closely adhering cells, 1 or more cells thick.

• Functions:

  • Covers body surfaces.

  • Lines body cavities.

  • Constitutes most glands.

• Features:

  • Avascular, nourished by underlying connective tissue.

Page 8: Functions of Epithelial Tissue

• Key Functions:

  • Protection: Prevents injury and infection to deeper tissues.

  • Secretion: Produces mucus, sweat, enzymes, hormones.

  • Excretion: Eliminates waste from tissues.

  • Absorption: Uptakes chemicals like nutrients.

  • Filtration: All substances exiting body are selectively filtered by epithelium.

  • Sensation: Nerve endings detect stimuli within epithelia.

Page 9: General Structure of Epithelia

• Composition:

  • Cells close together, minimal extracellular material.

  • High mitosis rate in cells adjacent to connective tissue.

• Basement Membrane:

  • Layer anchoring epithelium to underlying connective tissue, containing collagen and glycoproteins.

Page 10: Epithelial Cell Structure

• Cell Surfaces:

  • Basal Surface: Faces basement membrane.

  • Apical Surface: Faces away from basement membrane.

• Classification by Layers:

  • Simple Epithelia: Single layer with all cells anchored to the basement membrane.

  • Stratified Epithelia: Multiple layers, not all touching basement membrane.

Page 11: Cell Shapes and Epithelial Types

• Epithelial Classifications: Recognition of shapes and types involved.

Page 12: Simple Epithelia Overview

• Simple Epithelium: Single layer of cells, three types based on cell shapes:

  • Simple Squamous: Thin, scaly.

  • Simple Cuboidal: Squarish or rounded.

  • Simple Columnar: Tall and narrow.

  • Pseudostratified Columnar: Appears stratified but all cells touch the basement membrane; contains goblet cells.

Page 13: Simple Squamous Epithelium

• Characteristics:

  • Thin layer allowing rapid diffusion.

  • Secretory functions.

• Locations:

  • Alveoli, glomeruli, and endothelium.

Page 14: Simple Cuboidal Epithelium

• Characteristics:

  • Absorption, secretion, mucus production.

• Locations:

  • Liver, thyroid, mammary glands, kidney tubules.

Page 15: Simple Columnar Epithelium

• Characteristics:

  • Tall cells with nuclei at the basal half, can have microvilli or cilia.

• Functions:

  • Absorption, secretion of mucus.

• Locations:

  • GI tract, uterus, kidney, uterine tubes.

Page 16: Ciliated Pseudostratified Columnar Epithelium

• Characteristics:

  • Multilayered appearance, all cells contact the basement membrane.

  • Features cilia and goblet cells.

• Functions:

  • Secretion and propulsion of mucus.

• Locations:

  • Respiratory tract and portions of the male urethra.

Page 17: Stratified Epithelia Overview

• Characteristics:

  • Composed of 2 to 20+ layers of cells; deepest layer contacts basement membrane.

• Types Named By Surface Cell Shapes:

  • Stratified Squamous, Cuboidal, and Columnar.

  • Urothelium: Unique to urinary tract.

Page 18: Details of Stratified Epithelia

• Stratified Squamous:

  • Most widespread; deepest cells are mitotically active.

• Two Types:

  • Keratinized: On skin surface, abrasion resistant.

  • Nonkeratinized: Lines internal spaces without the dead cell layer.

Page 19: Keratinized Stratified Squamous Epithelium

• Characteristics:

  • Multiple cell layers, cells become flat toward the surface.

• Functions:

  • Resists abrasion and prevents water loss.

• Locations:

  • Epidermis, palms, soles.

Page 20: Nonkeratinized Stratified Squamous Epithelium

• Characteristics:

  • Similar to keratinized but lacks the surface layer of dead cells.

• Functions:

  • Resists abrasion and pathogen penetration.

• Locations:

  • Tongue, oral mucosa, esophagus, vagina.

Page 21: Stratified Cuboidal Epithelium

• Characteristics:

  • Two or more layers, surface cells are square or round.

• Functions:

  • Secretes sweat; produces ovarian hormones and sperm.

• Locations:

  • Sweat gland ducts, ovarian follicles, seminiferous tubules.

Page 22: Urothelium (Transitional Epithelium)

• Characteristics:

  • Multilayered with surface cells that transition shapes when stretched.

• Functions:

  • Allows filling of urinary tract.

• Locations:

  • Ureter and bladder.

Page 23: Introduction to Connective Tissue

• Expected Learning Outcomes:

  • Compare properties of connective tissues and identify components.

Page 24: Overview of Connective Tissue

• Defining Features:

  • Most abundant and variable tissue type, consisting predominantly of matrix.

• Characteristics:

  • Cells are not usually in direct contact; vascularity varies.

• Loose Connective Tissue: Many blood vessels.

• Cartilage: Avascular.

Page 25: Functions of Connective Tissues

• Main Functions:

  • Binding organs, support, physical protection, immune protection, movement, storage, heat production, and transport.

Page 26: Additional Functions of Connective Tissue

• Continued Functions:

  • Storage of fat, calcium, phosphorus; role in metabolic heat generation.

Page 27: Fibrous Connective Tissue Introduction

• Classification:

  • Grouped due to prominence of fibers.

• Components:

  • Cells (fibroblasts, macrophages, leukocytes, etc.)

Page 28: Fibrous Connective Tissue Features

• Components of Fibrous CT:

  • Fibers:

    • Collagenous: Tough, flexible, stretch-resistant.

    • Reticular: Thin and form frameworks for organs.

    • Elastic: Thinner, allow stretch and recoil.

Page 29: Tendons and Ligaments

• Visual Reference: Image depicting tendons and ligaments access.

Page 30: Ground Substance in Connective Tissue

• Definition: Featureless substance in which cells and fibers reside, often gelatinous or rubbery.

• Contents: Contains glycosaminoglycans (GAGs) and proteoglycans.

Page 31: Types of Fibrous Connective Tissue

• Main Categories:

  • Loose Connective Tissue: Mainly ground substance (areolar, reticular).

  • Dense Connective Tissue: Mainly fibers (dense regular, dense irregular).

Page 32: Areolar Tissue

• Characteristics:

  • Loosely organized fibers, abundant blood vessels.

  • Contains various cell and fiber types.

• Functions:

  • Supports epithelia, passageways for nerves and blood vessels.

Page 33: Reticular Tissue

• Characteristics:

  • Mesh of reticular fibers and fibroblasts.

• Functions:

  • Supports lymphatic organs.

• Locations:

  • Lymph nodes, spleen, thymus, bone marrow.

Page 34: Dense Regular Connective Tissue

• Characteristics:

  • Packed parallel collagen fibers.

  • Compressed fibroblast nuclei.

• Functions:

  • Provides strength and structure, attaches muscles to bones.

• Locations:

  • Tendons and ligaments.

Page 35: Dense Irregular Connective Tissue

• Characteristics:

  • Densely packed, randomly arranged collagen fibers.

• Functions:

  • Resistant to unpredictable stresses.

• Locations:

  • Deeper layer of skin, capsules around organs.

Page 36: Adipose Tissue Overview

• Characteristics:

  • Dominated by adipocytes, with space occupied by loose connective tissues.

• Functions:

  • Primary energy reservoir, insulation, cushioning.

Page 37: Adipose Tissue Features

• Structure:

  • Cells have thin margins; nucleus pressed against membrane.

• Functions:

  • Energy storage, insulation, cushioning.

Page 38: Cartilage Introduction

• Definition:

  • Stiff connective tissue with flexible matrix.

• Functions:

  • Shapes structure (ear, nose.

Page 39: General Features of Cartilage

• Characteristics:

  • Avascular, slow healing; matrix rich in GAGs and collagen.

• Types of Cartilage:

  • Hyaline, Fibrocartilage, Elastic.

Page 40: Hyaline Cartilage

• Characteristics:

  • Clear, glassy appearance due to fine collagen fibers.

• Functions:

  • Eases joint movement and supports airway.

• Locations:

  • Articular surfaces, costal cartilage, trachea.

Page 41: Elastic Cartilage

• Characteristics:

  • Contains numerous elastic fibers for flexibility.

• Functions:

  • Provides elastic support.

• Locations:

  • External ear, epiglottis.

Page 42: Fibrocartilage

• Characteristics:

  • Has coarse bundles of collagen fibers for durability.

• Functions:

  • Resists compression and absorbs shock.

• Locations:

  • Pubic symphysis, intervertebral discs.

Page 43: Bone (Osseous Tissue)

• Definition:

  • Calcified connective tissue forming the skeleton.

Page 44: Compact Bone Structure

• Description:

  • Cylinders surrounding central canals through which blood vessels and nerves travel.

Page 45: Blood Tissue Overview

• Definition:

  • Fluid connective tissue circulating through blood vessels.

• Functions:

  • Transports cells, nutrients, wastes.

Page 46: Blood Components

• Formed Elements:

  • Erythrocytes: Red blood cells, transport O2 and CO2.

  • Leukocytes: White blood cells, defend against infection.

  • Platelets: Cell fragments aiding in clotting.

Page 47: Nervous and Muscular Tissues Introduction

• Learning Outcomes:

  • Define excitable tissues, their neuron and muscle types, and recognize them visually.

Page 48: Excitability Definition

• Excitability:

  • Ability to respond to stimuli by altering membrane potential.

Page 49: Nervous Tissue Overview

• Definition:

  • Specialized for communication via electrical and chemical signals.

• Components:

  • Neurons (nerve cells) and neuroglia (supporting cells).

• Neuron Structure:

  • Cell body, dendrites, axon (nerve fiber).

Page 50: Visual Reference for Neurons and Glial Cells

• Neuronal Structure Visualized.

Page 51: Muscular Tissue Overview

• Definition:

  • Specialized for contraction and force exertion.

• Types:

  • Skeletal, Cardiac, Smooth.

Page 52: Skeletal Muscle Characteristics

• Definition:

  • Composed of long thin, multi-nucleated fibers.

• Functions:

  • Voluntary movement.

Page 53: Cardiac Muscle Overview

• Characteristics:

  • Short, branched cells with intercalated discs.

• Functions:

  • Involuntary control, unique to heart.

Page 54: Smooth Muscle Overview

• Characteristics:

  • Fusiform-shaped cells with central nucleus, no striations.

• Functions:

  • Involuntary movement in hollow organs.

Page 55: Summary of Cellular Junctions and Membranes

• Learning Outcomes:

  • Describe cellular junctions, glands, and membrane structures and functions.

Page 56: Cellular Junctions Defined

• Definition:

  • Connections facilitating communication and mechanical stability between cells.

Page 57: Tight Junctions

• Definition:

  • Interlocking connection preventing substances from passing between cells.

• Function:

  • Seals intercellular space, found in epithelia.

Page 58: Desmosomes

• Definition:

  • Patch holding cells together, resisting mechanical stress.

Page 59: Gap Junctions

• Definition:

  • Channels that facilitate communication between cells.

Page 60, 61, 62: Structure of Cellular Junctions

• Visual Illustrations:

  • Depict various types of cellular junctions and their components.

Page 63: Definition of Glands

• Gland:

  • Cell/organs secreting substances within the body or for excretion.

Page 64: Exocrine and Endocrine Glands

• Exocrine Glands:

  • Have ducts, secrete externally or internally.

• Endocrine Glands:

  • Secrete hormones directly into the bloodstream without ducts.

Page 65: Gland Development

• Visual Development Stages of Glands.

Page 66: Endocrine and Exocrine Gland Structure

• Visual Structures of Glands.

Page 67: Modes of Exocrine Secretion

• Types of Secretion:

  • Eccrine (Merocrine): Exocytosis.

  • Apocrine: Budding secretion.

  • Holocrine: Disintegrated whole cells.

Page 68: Visual Representation of Secretion Modes

• Illustration of Exocrine Secretion Methods.

Page 69: Overview of Membranes

• Types of Membranes:

  • Cutaneous, mucous, serous membranes.

Page 70: Histology of Mucous Membranes

• Structure:

  • Epithelial layer, lamina propria, muscularis mucosae.

Page 71: Serous Membrane Structure

• Definition:

  • Lines internal body cavities, has mesothelial layer.

Page 72: Tissue Growth and Repair Learning Goals

• Objectives:

  • Describe tissue growth types, transitions, and repair methods.

Page 73: Types of Tissue Growth

• Types:

  • Hyperplasia: Cell multiplication.

  • Hypertrophy: Increased cell size.

  • Neoplasia: Abnormal tissue growth (tumors).

Page 74: Tissue Development Overview

• Definitions:

  • Differentiation: Specialization of tissue.

  • Metaplasia: Transition from one mature tissue type to another.

Page 75: Stem Cells and Their Function

• Definition:

  • Undifferentiated cells with potential to become specialized.

Page 76: Tissue Repair Mechanisms

• Methods:

  • Regeneration: Replacement by the same cell type.

  • Fibrosis: Replacement with scar tissue.

Page 77: Tissue Degeneration and Death

• Concepts:

  • Atrophy: Shrinkage of tissue.

  • Necrosis: Pathological cell death.

Page 78: Illustrative Case of Dry Gangrene

• Illustration on Diabetes-Related Gangrene.

Page 79: Apoptosis Defined

• Description:

  • Programmed cell death for tissue homeostasis.

Page 80: Conclusion

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