Tissues, Glands, and Membranes Chapter Five Mrs. Hornacek
Objectives 1. Name the four main groups of tissues and give the location and general characteristics of each. 2. Differentiate between voluntary and involuntary muscles. 3. Describe the structure of the neuron. 4. Describe the function and location of the major types of connective tissue. 5. Describe the different structures and functions of epithelium tissue. 6. Distinguish among the 4 major types of membranes. 7. Describe the difference between endocrine and exocrine glands. 8. Identify tissues under a microscope and on diagrams.
Tissues Groups of cells that are similar in structure and perform a common or related function Histology is the study of tissues Chemical Cell Tissue Organ Organ System Whole Organism
Tissue Classification Four main types of tissue: Epithelial: covers surfaces, lines cavities, and forms glands Connective: supports and forms the framework of all parts of the body
Tissue Classification Four main types of tissue: Muscle: contracts and produces movement Nervous: conducts nerve impulses
Epithelial Tissue General Characteristics Epithelium forms a protective covering for the body It is the main tissue of the skin s outer layer Forms membranes, ducts, and lines body cavities and hollow organs
Epithelial Tissue General Characteristics Usually has no vascular tissue-blood supply Nutrients obtained by diffusion Cells reproduce rapidly (rapid healing) Cells are tightly packed together with no intercellular material Basement Membrane: Anchors epithelial tissue to connective tissue Thin, non-living
Structure of Epithelial Tissue Each epithelium is given two names: First name indicates # cell layers present Simple: single cell layer Stratified: two or more layers
Structure of Epithelial Tissue Second name describes the shape of its cells Squamous: flattened and scale-like Cuboidal: boxlike, tall as they are wide Columnar: tall and column shaped 6 types of epithelial tissue follow
Simple Squamous DESCRIPTION: Single layer of very thin, flattened cells FUNCTION: Diffusion and filtration where protection is not important LOCATION: air sacs of lungs, walls of capillaries and blood vessels, lining of heart
Fig05.01 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Free surface of tissue Simple squamous epithelium Basement membrane Nucleus (a) Connective tissue (b) The McGraw-Hill Companies, Inc./Al Telser, photographer Free surface of simple squamous epithelium Nucleus (c) (d) The McGraw-Hill Companies, Inc./Al Telser, photographer 11
Simple Cuboidal D: single layer of cube shaped cells F: secretion and absorption L: lining of kidney tubules, ducts of glands, covering surface of ovaries
Fig05.02 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Lumen Connective tissue Nucleus Basement membrane Free surface of tissue Simple cuboidal epithelium (a) The McGraw-Hill Companies, Inc./Al Telser, photographer (b) 13
Simple Columnar D: single layer of elongated cells, some have cilia and some may contain mucussecreting goblet cells F: absorption, secretion, protection, ciliated type propels substances (mucus, reproductive cells) by ciliary action L: lining of digestive tract, uterus, gallbladder
Fig05.03 Mucus Nucleus Cytoplasm Microvilli (free surface of tissue) Goblet cell Basement membrane (a) Connective tissue (b) The McGraw-Hill Companies, Inc./Al Telser, photographer 15
Pseudostratified Columnar D: appear stratified but really are a single layer with nuclei at various levels giving appearance of layered cells. F: secretion (mostly mucus), movement of mucus by cilia L: lining air passages like the trachea and upper respiratory tract
Fig05.04 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cilia (free surface of tissue) Cytoplasm Goblet cell Nucleus Basement membrane (a) Connective tissue The McGraw-Hill Companies, Inc./Dennis Strete, photographer (b) 17
Stratified Squamous D: multi-layered, dry, thick tissue. Surface cells are flat, full of keratin and dead. Basal cells are cuboidal or columnar. F: protection L: lining of esophagus, mouth, vagina, epidermis of the skin
Fig05.05 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Free surface of tissue Squamous cells Layer of dividing cells Basement membrane Connective tissue (a) (b) The McGraw-Hill Companies, Inc./Al Telser, photographer
Transitional Epithelium D: resembles both stratified squamous and stratified cuboidal F: stretches and also forms barrier to block diffusion L: lining of urinary bladder, ureters, urethra
Fig05.08 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Free surface of tissue Unstretched transitional epithelium Basement membrane (a) Underlying connective tissue (b) Ed Reschke Free surface of tissue Stretched transitional epithelium Basement membrane Underlying connective tissue (c) (d) Ed Reschke 21
Glands A gland is an organ specialized to produce a substance that is sent out to other parts of the body, made of glandular epithelium
Glands Glands are divided into two categories based on how they release secretions: 1. Exocrine: use ducts or tubes 2. Endocrine: secrete into the blood or tissue fluid
Types of Exocrine Glands Merocrine Releases fluid product through membrane by exocytosis Salivary glands, sweat glands in skin
Types of Exocrine Glands Apocrine Cellular product and portions of gland cells pinch off during secretion Mammary glands
Types of Exocrine Glands Holocrine Release entire cells filled with secretory products Sebaceous glands of the skin
Connective Tissue- General Characteristics Functions: bind, support, framework, store fat, fill spaces, produce blood cells, protect against infection, and repair tissue damage Most has a good blood supply, except cartilage
Connective Tissue Characteristics Composed of scattered cells with abundant non-living extracellular matrix Extracellular matrix contains fibers (for support) and ground substance (fluid, proteins)
Connective Tissue Major Cell Types Fibroblast most common secretes fibers very large, starshaped
Connective Tissue Major Cell Types Macrophage scavenger cells and defend against infection
Connective Tissue Major Cell Types Mast Cells release heparin and histamine Large located near blood vessels
Connective Tissue - Fibers Collagenous Fiber: strength Elastic Fiber: flexibility Reticular Fiber: supportive networks
5 Categories of Connective Tissue 1. Loose: areolar, adipose 2. Dense: tendons, ligaments 3. Cartilage: hyaline, elastic, fibrocartilage 4. Bone 5. Blood
1. Loose Connective Tissue Areolar D: gel-like matrix with fibers and different types of cells F: cushions organs, holds tissue fluid L: surrounding organs, under the skin, between muscles
Fig05.13 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Collagenous fiber Fibroblast Ground substance (a) Elastic fiber (b) The McGraw-Hill Companies, Inc./Dennis Strete, photographer 35
Areolar Connective Tissue
1. Loose Connective Tissue Adipose D: sparse matrix, closely packed F: insulates, supports, protects, reserve energy supply (fat storage) L: under skin, around joints, padding organs
Fig05.14 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fat droplet Cell membrane Nucleus (a) (b) The McGraw-Hill Companies, Inc./Al Telser, photographer 38
Adipose Connective Tissue
2. Dense Connective Tissue Strong Lacks good blood supply Dense D: dense with collagen and elastic fibers F: structural strength, attach muscle to bone and bone to bone L: vocal cords, tendons, ligaments
Fig05.15 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fibroblasts Collagenous fibers (a) (b) The McGraw-Hill Companies, Inc./Dennis Strete, photographer 41
Dense Regular Tendon. The fibers are oriented in parallel arrays. Note the thin, dark staining nuclei of the fibroblasts. Their cytoplasm cannot be distinguished.
3. Cartilage Hyaline Cartilage D: fine collagenous fibers in extracellular matrix with chondrocytes F: stiff but flexible support, reduces friction L: nose, ends of bones, ribs, larynx, trachea MOST COMMON TYPE
Fig05.16 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nucleus Lacuna Chondrocyte Extracellular matrix (a) (b) The McGraw-Hill Companies, Inc./Al Telser, photographer
Hyaline Cartilage Hyaline cartilage contains cells called chondrocytes embedded in a unique matrix that gives the tissue both strength and flexibility.
3. Cartilage Elastic Cartilage D: dense network of elastic fibers in extracellular matrix with chondrocytes F: elasticity, support L: external ear, parts of larynx
Fig05.17 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Elastic fibers Nucleus Lacuna Chondrocyte (a) Extracellular matrix (b) The McGraw-Hill Companies, Inc./Al Telser, photographer
Elastic Cartilage elastic cartilage can be distinguished by the stain for elastin that brings out the dense bundles
3. Cartilage Fibrocartilage Cartilage D: many collagenous fibers in extracellular matrix F: strong, resists compression L: invertebral discs and joint capsules (knees)
Fig05.18 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chondrocyte Nucleus Collagenous fiber (a) Extracellular matrix (b) The McGraw-Hill Companies, Inc./Al Telser, photographer
Fibrocartilage Fibrocartilage from an intervertebral disk. It is distinguished by very scattered, infrequent chondrocytes (see the tiny dark nuclei) and collagen fibers running in the matrix.
4. Bone Bone D: hard, calcified matrix with collagen fibers, vascular, deposits of mineral salts F: supports, protects, stores calcium, marrow inside is site for blood cell formation L: skeletal system
Fig05.19 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Osteon Lamella Central canal Lacuna Canaliculi (a) (b) The McGraw-Hill Companies, Inc./Dennis Strete, photographer (c) Prof. P. Motta/Univ."La Sapienza"/Photo Researchers 54
Bone Ground Bone Compact Bone
5. Blood Blood D: red and white blood cells in a fluid matrix F: transports gases, waste, nutrients, etc L: in blood vessels
Fig05.20 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. White blood cell Red blood cells Plasma (extracellular matrix of blood) Platelets (a) (b) The McGraw-Hill Companies, Inc./Dennis Strete, photographer
Blood Red Blood Cells and Lymphocytes Neutrophils and Eosinophils
Muscle Tissue General Characteristics: Highly cellular Very vascular Muscle fibers can contract and are responsible for most movement in the body
Muscle Tissue General Characteristics: Cells elongated Cells close together with little extracellular material Does NOT regenerate well, usually replaced with connective tissue
Types of Muscle Tissue (3) 1. Skeletal D: long, cylindrical, multinucleate cells, and striated F: voluntary movement, locomotion, generate heat when they contract L: attached to bone
Fig05.21 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Striations Nuclei Portion of a muscle fiber (a) (b) The McGraw-Hill Companies, Inc./Al Telser, photographer 62
Skeletal muscle (l.s.), 400x, demonstrating peripheral nuclei and banding pattern of skeletal muscle
Types of Muscle Tissue (3) 2. Smooth D: spindle-shaped, uninucleate cells, arranged closely to form sheets, NO STRIATIONS F: involuntary, move substances along internal passageways L: walls of hollow organs, stomach, gallbladder, urinary bladder
Fig05.22 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cytoplasm Nucleus (a) The McGraw-Hill Companies, Inc./Dennis Strete, photographer (b) 65
Smooth muscle (x.s. and l.s. small intestine) 400x, demonstrating size variation and cell shape.
Types of Muscle Tissue (3) 3. Cardiac D: branching, uninucleate cells, appears striated, fit together at junctions called intercalated discs F: involuntary, contractions propel blood into circulation L: bulk of the heart wall known as the myocardium
Fig05.23 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Striations Nucleus Intercalated disc (a) (b) The McGraw-Hill Companies, Inc./Al Telser, photographer 68
Cardiac muscle (l.s.), 400x, demonstrating smaller size of cardiac cells, central, single nucleus, and intercalated discs
Nervous Tissue General Characteristics: Main component of the nervous system Aware of our external environment Longest cells in the body Limited ability to repair themselves after an injury
Nervous Tissue General Characteristics: Contain two major cell types: 1. Neuron: highly specialized that generate and conduct nerve impulses 2. Neuroglia: supporting cells, insulate and protect neurons
The Neuron Dendrite: carries messages/impulses to the nerve cell body Soma Node of Ranvier Axon Terminal Schwann cell Nucleus Axon: The single fiber that carries impulses away from the body Myelin: insulating matter that covers the axon
Nervous Tissue D: Neurons and neuroglia F: Regulate and control body functions L: Brain, spinal cord, and nerves
Fig05.24 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Nuclei of neuroglia Cellular process Cytoplasm Cell membrane Nucleus (a) (b) Royalty-Free/Corbis 74
Nervous tissue (Purkinje cell of cerebellum), 1000x
Membranes Membranes are thin sheets of tissue They are made of both epithelial tissue and connective tissue Cover body surfaces and line body cavities
Epithelial Membranes 4 Types 1. Serous 2. Mucous 3. Cutaneous 4. Synovial
1. Serous Membrane Line body cavities that lack openings to the outside thorax abdomen cover the organs in these cavities Secrete a thin, watery lubricant (serous fluid) so organs can move with minimum friction
2. Mucous Membrane Line cavities and tubes that open to the outside of the body oral and nasal cavities tubes of digestive, respiratory, urinary, and reproductive Produce a thick and sticky substance called mucus
3. Cutaneous Membrane Known as the skin Has an outer layer of epithelium Complex
4. Synovial Membrane Made of connective tissue Lines joints We will discuss more in the skeletal system