Tissues Chapter 5

Tissue Definition – an aggregation of cells in which each cooperates with all others in the performance of a given function Examples of general functions Movement Protection Support Production of chemicals

Principal Tissue Types Epithelial Connective Muscular Nervous

Human Anatomy, 3rd edition Epithelial Tissue Functions Coverings and linings Forms glands Characteristics Closely packed cells Continuous sheets Basement membrane Avascular Classification Simple Stratified Human Anatomy, 3rd edition Prentice Hall, © 2001

Epithelia of Coverings and Linings

Squamous Epithelium Simple Squamous Epithelium Highly adapted to diffusion, osmosis, & filtration www.stegen.k12.mo.us/.../TissueSlides.htm

Squamous Epithelium Stratified Squamous Epithelium Surface layer is flat Function - protection www.stegen.k12.mo.us/.../TissueSlides.htm

Cuboidal Epithelium Simple cuboidal epithelium Function – secretion and absorption Lines glands and their ducts Stratified Cuboidal epithelium Surface layer cube-shaped Function – protection www.stegen.k12.mo.us/.../TissueSlides.htm

Glandular Epithelium Gland – 1 or more cells Function – secretion Types Exocrine – to surface or ducts Endocrine – to blood

Transitional Epithelium Can be stretched Lines hollow structures that expand Function – prevents rupture of organ http://www.mhhe.com/biosci/ap/histology_mh/stratepi.html

Columnar Epithelia Simple columnar epithelium Functions Protection, Absorption or secretion Stratified columnar epithelium More than one layer Function Protection www.stegen.k12.mo.us/.../TissueSlides.htm

Pseudostratified Columnar Epithelium Appear stratified but all cells connect to the basement membrane Functions Protection Secretion http://bioweb.uwlax.edu/zoolab/Table_of_Contents/Lab-1b/Pseudostratified_Model_1/pseudostratified_model_1.htm

Connective Tissue Most abundant tissue Functions are varied Characteristics Specialized cells, widely scattered Rich blood supply Much matrix Extracellular fibers Ground substance

Cell Types Found in Connective Tissue Fibroblasts Secrete the molecules that form the matrix Fixed cells Fibrocytes Macrophages “Big eaters” May be fixed or wandering

Connective Tissue Fibers Collagen fibers Most common type White Strong, ropelike Form ligaments, tendons Reticular fibers Thin Woven into rough, flexible network Elastic fibers Yellow Stretch Contain elastin

Ground Substance Extracellular fluid in connective tissue Water Glycoproteins

Types of Connective Tissue

Loose (Areolar) Connective Tissue Fibers not abundant Contains all 3 types of fibers Examples of locations Between skin and muscles Around digestive tract Around blood vessels Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Adipose Tissue Most of the volume is adipocytes Provides padding, slows heat loss, food reserve Locations Wherever there is loose connective tissue Human Anatomy, 3rd edition Prentice Hall, © 2001

Dense Connective Tissue Types Dense Regular Connective Tissue Dense Irregular Connective Tissue Elastic Connective Tissue

Dense Regular Connective Tissue Lots of collagen fibers in bundles Cells – fibroblasts in rows between bundles Examples Tendons, ligaments Human Anatomy, 3rd edition Prentice Hall, © 2001

Dense Irregular Connective Tissue Tensions in various directions Occurs in sheets Locations Periosteum Perichondrium Fibrous capsules of some organs Fasciae Dermis Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Elastic Tissue Lots of elastic fibers Fibroblasts in spaces between fibers Provides stretch and strength Human Anatomy, 3rd edition Prentice Hall, © 2001

Cartilage Dense network of collagenous fibers & elastic fibers in a gel-like substance Cells – chondrocytes in lacunae Chondroblasts Perichondrium – surrounds surface of cartilage

Types of Cartilage Hyaline cartilage Fibrocartilage Elastic cartilage

Human Anatomy, 3rd edition Hyaline Cartilage Most common Provides flexibility and support Locations Ends of bones Trachea Larynx Embryonic skeleton Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Fibrocartilage Visible collagenous fibers with scattered chondrocytes Provides strength and rigidity Locations Intervertebral discs Symphysis pubis Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Elastic Cartilage Threadlike network of elastic fibers with chondrocytes Provides strength and maintains shape Locations Pinna Eustacian tube Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Bone Solid matrix Cells Osteocytes in lacunae Osteoblasts Osteoclasts Periosteum surrounds surface of bone Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Blood Functions Transport medium Regulation Protection Composition Plasma – fluid Formed elements – cells & cell fragments Erythrocyte Leukocyte Thrombocyte Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition A Red Blood Cell FG20_02D.JPG Title: Anatomy of Red Blood Cells Notes: (a)Standard red blood smear. (b)Rouleaux formation as red blood cells travel through a capillary. (c)SEM of red blood cells; 3-dimensional structure. (d)Sectional view of red blood cell. Keywords: red blood cell, rouleaux, capillary, sectional view Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition SEM of RBCs SEMFG20_02C.JPG Title: Anatomy of Red Blood Cells Notes: (a)Standard red blood smear. (b)Rouleaux formation as red blood cells travel through a capillary. (c)SEM of red blood cells; 3-dimensional structure. (d)Sectional view of red blood cell. Keywords: red blood cell, rouleaux, capillary, sectional view Human Anatomy, 3rd edition Prentice Hall, © 2001

Muscular Tissue Specialized cells Function - contraction 3 types Skeletal muscle Cardiac muscle Smooth muscle

Human Anatomy, 3rd edition Skeletal Muscle Connected to bones Striated Multinucleated Voluntary Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Cardiac Muscle Found in the heart Striations Intercalated discs Involuntary Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Smooth Muscle Found in walls of internal organs Nonstriated Involuntary Human Anatomy, 3rd edition Prentice Hall, © 2001

Human Anatomy, 3rd edition Nervous Tissue Specialized cells Function – conduction of electrical impulses Cells Neurons Neuroglia Human Anatomy, 3rd edition Prentice Hall, © 2001