Principles of Anatomy and Physiology Tissue Level PDF

Principles of Anatomy and Physiology Gerard Tortora and Bryan Derrickson Sixteenth Edition The Tissue Level of Organization This slide deck contains animations. Please disable a...

Principles of Anatomy and Physiology Gerard Tortora and Bryan Derrickson Sixteenth Edition The Tissue Level of Organization This slide deck contains animations. Please disable animations if they cause issues with your device. Copyright ©2021 John Wiley & Sons, Inc. Introduction Objectives: Types of tissues How cells of a tissue are held together Compare and contrast epithelial, connective, muscular, and nervous tissue Structure and function of membranes Copyright ©2021 John Wiley & Sons, Inc. 2 Types of Tissues Copyright ©2021 John Wiley & Sons, Inc. 3 What Is a Tissue? A tissue is a group of cells that function together to carry out specialized activities There are 4 basic types of tissues in the human body and they are categorized according to their structure and function 1. Epithelial 2. Connective 3. Muscular 4. Nervous Copyright ©2021 John Wiley & Sons, Inc. 4 The 4 Tissue Types Epithelial, Connective, Muscular, Nervous Copyright ©2021 John Wiley & Sons, Inc. 5 Types of Tissues Body tissues are classified into four basic types based on their structure and functions: 1. Epithelial tissue – covers body surfaces; lines body cavities, hollow organs, and ducts; and forms glands. 2. Connective tissue – protects and supports the body and its organs, binds organs together, stores energy reserves as fat, and provides immunity. 3. Muscular tissue – generates the physical force needed to make body structures move. 4. Nervous tissue – detects changes inside and outside the body and initiates and transmits nerve impulses that coordinate body activities to help maintain homeostasis. Copyright © 2018 John Wiley & Sons, Inc. 6 Cell Junctions Copyright ©2021 John Wiley & Sons, Inc. 7 Cell Junctions Cells can be held together in a number of ways. These points of contact between cells are called cell junctions. Copyright ©2021 John Wiley & Sons, Inc. 8 Tight Junctions weblike strands of transmembrane proteins fuse together the plasma membranes of neighboring cells Prevents leaking of contents. Lines stomach intestines and bladder Copyright ©2021 John Wiley & Sons, Inc. 9 Adhering Junctions Transmembrane glycoproteins join cells Adhering junctions often form extensive zones called adhesion belts Resists separation during contractile activity of muscle in the intestine Copyright ©2021 John Wiley & Sons, Inc. 10 Desmosomes Plaques and transmembrane glycoproteins that extend into the intercellular space Filaments extend across the cell from one junction to the other. Desmosomes prevent epidermal cells and cardiac cells from separating under tension. Copyright ©2021 John Wiley & Sons, Inc. 11 Hemidesmosomes Like desmosomes except provides strong attachment to basement membrane of epithelial tissue. Abundant in tissues where there is constant abrasive forces. Copyright ©2021 John Wiley & Sons, Inc. 12 Gap Junctions Gap junctions allow small molecules, ions and electrical impulses between cells. Abundant in cardiac tissue where there is electrical coupling of cardiomyocytes. Copyright ©2021 John Wiley & Sons, Inc. 13 Intercellular Junction Interactions Animation: Intercellular Junctions Copyright ©2021 John Wiley & Sons, Inc. 14 Epithelial Tissue Copyright ©2021 John Wiley & Sons, Inc. 15 General Features of Epithelial Tissue Cells are arranged in sheets and are densely packed Many cell junctions are present Forms surfaces Epithelial cells attach to a basement membrane Epithelial tissue is avascular but does have a nerve supply (blood supply is nearby however) Cells replicate frequently Copyright ©2021 John Wiley & Sons, Inc. 16 Surfaces of Epithelial Cells and the Basement Membrane Copyright ©2021 John Wiley & Sons, Inc. 17 Surfaces of Epithelial Cells and the Basement Membrane Copyright ©2021 John Wiley & Sons, Inc. 18 Epithelial Tissue Epithelial tissue may be divided into two types: 1. Covering and lining epithelium 2. Glandular epithelium As its name suggests, covering and lining epithelium forms the outer covering of the skin and the outer covering of some internal organs. It also lines body cavities; blood vessels; ducts; and the interiors of the respiratory, digestive, urinary, and reproductive systems. The cells of epithelial tissue have an apical surface, which is exposed to a body cavity, lining of an internal organ, or the exterior of the body; lateral surfaces, which face cells on either side; and a basal surface, which is deep. Copyright © 2018 John Wiley & Sons, Inc. 19 Classification of Epithelial Tissue Covering and lining epithelia are classified according to the shape of the cells and how many layers thick they are Copyright ©2021 John Wiley & Sons, Inc. 20 Epithelial Tissue Arrangement of cells in layers: Simple epithelium is a single layer of cells that functions in diffusion, osmosis, filtration, secretion, and absorption. Pseudostratified epithelium (pseudo = false) appears to have multiple layers of cells because the cell nuclei lie at different levels and not all cells reach the apical surface. Stratified epithelium (stratum = layer) consists of two or more layers of cells that protect underlying tissues in locations where there is considerable wear and tear. Copyright © 2018 John Wiley & Sons, Inc. 21 Epithelial Tissue Cell shapes: Squamous cells – are thin, and this allows for the rapid passage of substances through them. Cuboidal cells – are as tall as they are wide and are shaped like cubes or hexagons. They may have microvilli at their apical surface and function in either secretion or absorption. Columnar cells – are much taller than they are wide, like columns, and protect underlying tissues. Their apical surfaces may have cilia or microvilli, and they often are specialized for secretion and absorption. Transitional cells – change shape, from flat to cuboidal and back, as organs such as the urinary bladder distends. Copyright © 2018 John Wiley & Sons, Inc. 22 Epithelial Tissue Simple epithelium: o Simple squamous epithelium o Simple cuboidal epithelium o Simple columnar epithelium (nonciliated/ciliated) o Pseudostratified columnar (nonciliated/ciliated) Stratified epithelium: o Stratified squamous epithelium (keratinized and non- keratinized) o Stratified cuboidal epithelium o Stratified columnar epithelium o Transitional epithelium Copyright © 2018 John Wiley & Sons, Inc. 23 Epithelial Tissue: Surface Epithelium (1 of 13) A. Simple Squamous Epithelium Description Single layer of flat cells that resembles a tiled floor when viewed from apical surface; centrally located nucleus. Location Lines the CV and lymphatic system (called endothelium); forms epithelial layer of serous membrane in abdominal and thoracic cavities (called mesothelium); Also in air sacs of lungs, kidneys, cornea and tympanic membrane. Function Present at sites of filtration (kidneys) or diffusion (lungs) and secretion in serous membranes. Copyright ©2021 John Wiley & Sons, Inc. 24 Epithelial Tissue: Surface Epithelium (2 of 13) A. Simple Squamous Epithelium, continued Copyright ©2021 John Wiley & Sons, Inc. 25 Epithelial Tissue: Surface Epithelium (3 of 13) B. Simple Cuboidal Epithelium Description Single layer of cube-shaped cells; round, centrally located nucleus. Cuboidal shape easily viewed when tissue sectioned and viewed from side. Location Covers surface of ovary; lines anterior surface of capsule of eye lens; forms pigmented epithelium at posterior surface of retina; lines kidney tubules and small ducts in glands. Function Secretion and absorption. Copyright ©2021 John Wiley & Sons, Inc. 26 Epithelial Tissue: Surface Epithelium (4 of 13) C. Nonciliated Simple Columnar Epithelium Description Single layer of nonciliated column like cells with oval nuclei near base of cells; contains 1) columnar epithelial cells with microvilli at apical surface and 2) goblet cells. Location Lines GI tract, ducts of many glands in different organs and gallbladder. Function Secretion and absorption; Mucus lubricates lining of digestive, respiratory, and reproductive tracts, and most of urinary tract; helps prevent destruction of stomach lining by acidic stomach juices. Copyright ©2021 John Wiley & Sons, Inc. 27 Epithelial Tissue: Surface Epithelium (5 of 13) D. Ciliated Simple Columnar Epithelium Description Single layer of ciliated column like cells with oval nuclei near base of cells. Goblet cells usually interspersed. Location Lines some bronchioles, uterine tubes, uterus, paranasal sinuses, central canal of spinal cord and ventricles of brain. Function In respiratory system, cilia beat in unison to move mucus and foreign particles toward throat to be coughed up or swallowed. Cilia also move oocytes from ovaries through fallopian tubes into uterus. Copyright ©2021 John Wiley & Sons, Inc. 28 Epithelial Tissue: Surface Epithelium (6 of 13) E. Nonciliated Pseudostratified Columnar Epithelium Description Appears to have several layers because the nuclei are a various levels. Even though the cells are attached to the basement membrane in a single layer, some cells do no extend to the apical surface. When viewed from the side, this gives the false impression of a multi-layered tissue (pseudo = false). Contains cells without cilia and also lacks goblet cells. Location Lines epididymis, larger ducts of many glands and parts of male urethra. Function Absorption and secretion. Copyright ©2021 John Wiley & Sons, Inc. 29 Epithelial Tissue: Surface Epithelium (7 of 13) F. Ciliated Pseudostratified Columnar Epithelium Description Appears to have several layers because cell nuclei are at various levels. All cells attached to basement membrane in a single layer but some cells do not extend to apical surface. When viewed from the side, it appears multi-layered (pseudo = false). Contains cells that extend to surface and secrete mucus (goblet cells) or bear cilia. Location Lines airways of most upper respiratory tract. Function Secretes mucus that traps foreign particles, and cilia sweep away mucus for elimination from body. Copyright ©2021 John Wiley & Sons, Inc. 30 Epithelial Tissue: Surface Epithelium (8 of 13) F. Ciliated Pseudostratified Columnar Epithelium, continued Copyright ©2021 John Wiley & Sons, Inc. 31 Epithelial Tissue: Surface Epithelium (9 of 13) G. Stratified Squamous Epithelium Description Contains two or more layers of cells. Cells in apical layer and several layers deep to it are squamous; As basal cells divide daughter cells arising from cell divisions push upward toward apical layer. There are two types: keratinized stratified squamous epithelium (contain keratin) and nonkeratinized stratified squamous epithelium (does not contain large amounts of keratin). Location Keratinized variety forms superficial layer of skin; Nonkeratinized variety lines wet surfaces (lining of mouth, esophagus, part of epiglottis, party of pharynx and vagina) and covers tongue. Function Protection against abrasion, water low, UV radiation, and foreign invasion. First line of defense against microbes. Copyright ©2021 John Wiley & Sons, Inc. 32 Epithelial Tissue: Surface Epithelium (10 of 13) G. Stratified Squamous Epithelium, continued Copyright ©2021 John Wiley & Sons, Inc. 33 Epithelial Tissue: Surface Epithelium (11 of 13) H. Stratified Cuboidal Epithelium Description Has two or more layers of cells; cells in apical layer are cube-shaped; fairly rate type. Location Ducts of adult sweat glands and esophageal glands, part of male urethra. Function Protection; limited secretion and absorption. Copyright ©2021 John Wiley & Sons, Inc. 34 Epithelial Tissue: Surface Epithelium (12 of 13) I. Stratified Columnar Epithelium Description Basal layers consist of shortened, irregularly shaped cells; only apical layer has columnar cells; uncommon. Location Lines part of urethra; large excretory ducts of some glands, such as esophageal glands; small areas in anal mucous membrane; part of conjunctiva of eye. Function Protection and secretion. Copyright ©2021 John Wiley & Sons, Inc. 35 Epithelial Tissue: Surface Epithelium (13 of 13) J. Urothelium (Transitional Epithelium) Description Has a variable appearance (transitional). In relaxed or unstretched state, looks like stratified cuboidal epithelium, except apical layer cells tend to be large and rounded. As tissue is stretched, cells become flatter, giving the appearance of stratified squamous epithelium. Multiple layers and elasticity make it ideal of lining hollow structures (urinary bladder) subject to expansion from within. Location Lines urinary bladder, ureters, and portions of urethra. Function Allows urinary organs to stretch and maintain protective lining while holding variable amounts of fluid without rupturing. Copyright ©2021 John Wiley & Sons, Inc. 36 Glandular Epithelium A gland is a single cell or a mass of epithelial cells adapted for secretion The secretions of endocrine glands enter the interstitial fluid and diffuse into the bloodstream The secretions of exocrine glands enter ducts that empty onto the surface of a covering/lining epithelium such as the skin surface or the lumen of the stomach Copyright ©2021 John Wiley & Sons, Inc. 37 Glandular Epithelium (1 of 2) A. Endocrine Glands Description Endocrine gland secretions (hormones) enter interstitial fluid and then diffuse into bloodstream without flowing through a duct. Endocrine glands will be described in detail in Chapter 18. Location Examples include pituitary gland at base of brain, pineal gland in brain, thyroid and parathyroid glands near larynx (voice box), adrenal glands superior to kidneys, pancreas near stomach, ovaries in pelvic cavity, testes in scrotum, thymus in thoracic cavity. Function Hormones regulate many metabolic and physiological activities to maintain homeostasis. Copyright ©2021 John Wiley & Sons, Inc. 38 Glandular Epithelium (2 of 2) B. Exocrine Glands Description Exocrine gland secretory products are released into ducts that empty onto surface of a covering and lining epithelium, such as skin surface or lumen of lumen of hollow organ. Location Sweat, oil, and earwax glands of skin; digestive glands such as salivary glands (secrete into mouth cavity) and pancreas (secretes into small intestine). Function Produce substances such as sweat to help lower body temperature, oil, earwax, saliva, or digestive enzymes. Copyright ©2021 John Wiley & Sons, Inc. 39 Epithelial Tissue Anatomy Overview: Epithelial Tissues Copyright ©2021 John Wiley & Sons, Inc. 40 Connective Tissue Copyright ©2021 John Wiley & Sons, Inc. 41 Connective Tissue Connective tissue is one of the most abundant and widely distributed tissues in the body. In its various forms, connective tissue has a variety of functions. It binds together, supports (bones & Cartilage), and strengthens (extracellular matrix) body tissues; protects and insulates (adipose) internal organs; compartmentalizes structures such as skeletal muscles (muscle fascia); is the major transport system within the body (blood, a fluid); is the major site of stored energy reserves (adipose); and is the main site for immune responses. Connective tissue consists of two basic elements: cells and extracellular matrix. The extracellular matrix is the material between its widely spaced cells and consists of ground substance and fibers. Copyright © 2018 John Wiley & Sons, Inc. 42 Connective vs Epethelial Tissue Copyright © 2018 John Wiley & Sons, Inc. 43 Connective Tissue Types of connective tissue cells: Fibroblasts are large, flat cells with branching processes. They are present in many connective tissues, and usually the most numerous. Produce connective tissue (fibers & ground substances) and have a role in wound healing. Macrophages are white blood cells that have phagocytic ability in removing dead cells and foreign substances and initiate immune responses. Other white blood cells (neutrophils, basophils, eosinophils) provide and immune and inflammatory responses. Plasma cells form immunoglobulins in an immune response. Mast cells are involved in immunity and the inflammation. Adipocytes store fat and have a role in endocrine function and provide protection and insulation for internal organs. Copyright © 2018 John Wiley & Sons, Inc. 44 Connective Tissue Extracellular matrix consists of: Ground substance is the component of connective tissue between cells and fibers. Made of water and organic substances. It supports cells, binds them together, and provides a medium through which substances are exchanged between the blood and cells. Fibers in the extracellular matrix strengthen and support connective tissues. Three types of fibers are embedded in the extracellular matrix between the cells: collagen fibers, elastic fibers, and reticular fibers. Copyright © 2018 John Wiley & Sons, Inc. 45 Connective Tissue (Cells and Fibers) Copyright ©2021 John Wiley & Sons, Inc. 46 Connective Tissue 3 types of fibers imbedded in the extracellular matrix Collagen fibers are very strong and resist pulling forces, but they are not stiff, which promotes tissue flexibility. Elastic fibers are smaller in diameter than collagen fibers, branch and join together to form a network within a tissue. Elastic fibers are strong but can be stretched up to 1½ times their relaxed length without breaking. Reticular fibers, provide support in the walls of blood vessels and form branching networks around fat cells, nerve fibers, and skeletal and smooth muscle cells. Copyright © 2018 John Wiley & Sons, Inc. 47 Connective Tissue Extracellular Matrix (2 of 2) Fibers in the extracellular matrix provide strength and support to a tissue and consist of 3 types: Collagen fibers Elastic fibers Reticular fibers Copyright ©2021 John Wiley & Sons, Inc. 48 Connective Tissue Extracellular Matrix (1 of 2) Extracellular matrix is located in the spaces between connective tissue cells Extracellular matrix is composed of fibers and ground substance Copyright ©2021 John Wiley & Sons, Inc. 49 Classification of Connective Tissue Loose Dense Cartilage Bone Liquid (blood and lymph) Different connective tissue types is made up of various types and arrangements of connective tissue cells and extracellular matrix. Copyright ©2021 John Wiley & Sons, Inc. 50 Classification of Connective Tissues Loose connective tissue are loosely arranged cells which make up adipose tissue and reticular connective tissue. Dense connective tissue contains more numerous, thicker, and denser fibers (more closely packed), but fewer cells than loose connective tissue. Makes up the tissue of ligaments and tendons Copyright © 2018 John Wiley & Sons, Inc. 51 Classification of Connective Tissues Cartilage consists of a dense network of collagen fibers or elastic fibers. o The cells of mature cartilage are called chondrocytes. o Since cartilage has no blood supply, it heals poorly following injury. Copyright © 2018 John Wiley & Sons, Inc. 52 Classification of Connective Tissues Bone tissue supports soft tissues, protects delicate structures, and works with skeletal muscles to generate movement. Bone stores calcium and phosphorus; stores red bone marrow, which produces blood cells; and houses yellow bone marrow, a site for triglycerides. Blood tissue and lymph are an example of liquid connective tissue that has a liquid extracellular matrix. Copyright © 2018 John Wiley & Sons, Inc. 53 Connective Tissues: Loose Connective Tissue Copyright © 2018 John Wiley & Sons, Inc. 54 Connective Tissues: Loose Connective Tissue Copyright © 2018 John Wiley & Sons, Inc. 55 Connective Tissues: Loose Connective Tissue Copyright © 2018 John Wiley & Sons, Inc. 56 Connective Tissues: Dense Connective Tissue Copyright © 2018 John Wiley & Sons, Inc. 57 Connective Tissues: Dense Connective Tissue Copyright © 2018 John Wiley & Sons, Inc. 58 Connective Tissues: Dense Connective Tissue Copyright © 2018 John Wiley & Sons, Inc. 59 Supporting Connective Tissue—Cartilage A. Hyaline Cartilage Description Contains resilient gel as ground substance and appears as a bluish-white, shiny substance; prominent chondrocytes are found in cartilage lacunae surrounded by perichrondrium (exceptions: articular cartilage in joints and cartilage of growth plates, where bones lengthen during growth). Location Most abundant cartilage in body; at ends of long bones, anterior ends of ribs, nose, parts of larynx, trachea, bronchi, bronchial tubes, embryonic and fetal skeleton. Function Provides smooth surfaces for movement at joints, flexibility, and support; weakest type of cartilage and can be fractured. Copyright ©2021 John Wiley & Sons, Inc. 60 Supporting Connective Tissue—Cartilage B. Fibrous Cartilage Description Has chondrocytes among clearly visible thick bundles of collagen fibers within extracellular matrix; lacks perichondrium. Location Pubic symphysis, intervertebral discs, menisci of knee, portions of tendons that insert into cartilage. Function Support and joining structures together. Strength and rigidity make it the strongest type of cartilage. Copyright ©2021 John Wiley & Sons, Inc. 61 Supporting Connective Tissue—Cartilage C. Elastic Cartilage Description Has chondrocytes in a threadlike network of elastic fibers within extracellular matrix; perichondrium present. Location Epiglottis, part of external ear (auricle), auditory (esutachian) tubes. Function Provides strength and elasticity; maintains shape of certain structures. Copyright ©2021 John Wiley & Sons, Inc. 62 Supporting Connective Tissue—Bone Tissue Description Compact bone tissue consists of osteons (haversian systems) that contain bone lamellae, bone lacunae, osteocytes, bone canaliculi, and central (haversian) canals. Spongy bone tissue consists of thin columns called trabeculae; spaces between trabeculae are filled with red bone marrow. Location Both compact and spongy bone tissue make up the various parts of bones of the body. Function Support, protection, storage; houses blood-forming tissue; serves as levers that act with muscle tissue to enable movement. Copyright ©2021 John Wiley & Sons, Inc. 63 Liquid Connective Tissue—Blood Description Consists of blood plasma and formed elements: red blood cells (erythrocytes), white blood cells (leukocytes), platelets (thrombocytes). Location Within blood vessels (arteries, arterioles, capillaries, venules, veins), within chambers of heart. Function Red blood cells: transport oxygen and some carbon dioxide; White blood cells: carry on phagocytosis and mediate allergic reactions and immune system responses; Platelets: essential for clotting. Copyright ©2021 John Wiley & Sons, Inc. 64 Connective Tissue Anatomy Overview: Connective Tissues Copyright ©2021 John Wiley & Sons, Inc. 65 Membranes Copyright ©2021 John Wiley & Sons, Inc. 66 Membranes Membranes are flat sheets of pliable tissue that cover or line a part of the body. The combination of an epithelial layer and an underlying connective tissue layer constitutes an epithelial membrane. Types of membranes: o Mucous membranes or mucosa line a body cavity that opens directly to the exterior. Mucous membranes line the entire digestive, respiratory, and reproductive systems. o Cutaneous membranes is the skin that covers the surface of the body o Serous membranes line a body cavity that does not open directly to the exterior, and it also covers the organs that lie within the cavity. o Synovial membranes line the cavities of some joints. Copyright © 2018 John Wiley & Sons, Inc. 67 Membranes Copyright ©2021 John Wiley & Sons, Inc. 68 Membranes Copyright ©2021 John Wiley & Sons, Inc. 69 Muscular Tissue Copyright ©2021 John Wiley & Sons, Inc. 70 General Characteristics of Muscular Tissue Muscular tissue consists of fibers that provide motion, maintain posture, and produce heat 3 types of muscle tissue: 1. Skeletal muscle 2. Cardiac muscle 3. Smooth muscle Copyright ©2021 John Wiley & Sons, Inc. 71 Muscular Tissue A. Skeletal Muscle Tissue Description Consists of long, cylindrical, striated fibers. Vary greatly in length, from a few centimeters in short muscles to 30-40 cm in the longest muscles. A muscle fiber is roughly cylindrical, multinucleated cell with nuclei at the periphery. It is voluntary because it can be made to contract or relax by conscious control. Location Usually attached to bones by tendons. Function Motion, posture, heat production, protection. Copyright ©2021 John Wiley & Sons, Inc. 72 Muscular Tissue B. Cardiac Muscle Tissue Description Consists of branched, striated fibers with usually only one centrally located nucleus. Attach end to end by transverse thickenings of plasma membrane called intercalated discs, which contain desmosomes and gap junctions. Desmosomes strengthen tissue and hold fibers together during vigorous contractions. Gap junctions provide route for quick conduction of electrical signals throughout heart. Involuntary control. Location Heart wall. Function Pumps blood to all parts of body. Copyright ©2021 John Wiley & Sons, Inc. 73 Muscular Tissue C. Smooth Muscle Tissue Description Consists of nonstriated fibers (lacking striations, hence the term smooth). Smooth muscle fiber is a small spindle-shaped cell thickest in the middle, tapering at each end, and containing a single, centrally located nucleus. Gap junctions connect many individual fibers in some smooth muscle tissue. Usually involuntary; can product powerful contractions as many muscle fibers contract in unison. Where gap junctions are absent, such as iris of eye, smooth muscle fibers contract individually, like skeletal muscle fibers. Location Iris of eyes; walls of hollow internal structures such as blood vessels, airways to lungs, stomach, intestines, gallbladder, urinary bladder, and uterus. Function Motion (constriction of blood vessels and airways, propulsion of foods through gastrointestinal tract, contraction of urinary bladder and gallbladder). Copyright ©2021 John Wiley & Sons, Inc. 74 Muscle Tissue Anatomy Overview: Muscular Tissue Copyright ©2021 John Wiley & Sons, Inc. 75 Nervous Tissue Copyright ©2021 John Wiley & Sons, Inc. 76 General Characteristics of Nervous Tissue Two kinds of cells: Neurons Neuroglia Most neurons have a cell body, dendrites, and axons Neurons or nerve cells, are sensitive to various stimuli. They convert stimuli into nerve impulses (action potentials) and conduct these impulses to other neurons, muscle fibers, or glands. Neuroglia do not generate or conduct nerve impulses, but they do have many other important protective and supportive functions. Copyright ©2021 John Wiley & Sons, Inc. 77 Nervous Tissue Description Consists of (1) neurons (nerve cells), which consist of cell body and processes extending from cell body (one to multiple dendrites and a single axon); and (2) neuroglia, which do not generate or conduct nerve impulses but have other important supporting functions. Location Nervous system. Function Exhibits sensitivity to various types of stimuli; converts stimuli into nerve impulses (action potentials); conducts nerve impulses to other neurons, muscle fibers, or glands. Copyright ©2021 John Wiley & Sons, Inc. 78 Nervous Tissue Anatomy Overview: Nervous Tissue Copyright ©2021 John Wiley & Sons, Inc. 79 Copyright Copyright © 2021 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in Section 117 of the 1976 United States Copyright Act without the express written permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information contained herein. Copyright ©2021 John Wiley & Sons, Inc. 80