Animal Tissue Packet #52 Chapter #40

Introduction Animals are predators and must be strong and agile Means that tissue must possess characteristics of capable of rapid movement and the cells that make up the tissue must be able to generate and transmit forces and change shape quickly

Animal Tissue II Epithelial tissue Connective Tissues Muscular Tissue Nervous Tissue

Connective tissue Animal Tissue

Connective Tissue I Characteristics Extremely varied Tough and flexible Tendons Dermis of the skin Hard and dense Bone Resilient and shock- absorbing Cartilage Soft and transparent Jelly that fills interior of the eye

Connective Tissue II Functions Supporting function Cartilage Bone Transport function Blood

Connective Tissue III Bulk of this tissue is composed of extracellular matrix Tensile strength provided by the fibrous protein collagen

Connective Tissue IV Collagen There are 20 different variations of the protein Chief proteins in bone, tendon and skin Make up 25% of the total protein mass in a mammal More than any other type of protein Collagen is long, stiff and a triple stranded helical structure Collagen fibrils nm in diameter

Connective Tissue V Collagen Homework Question How does procollagen and the extracellular enzyme collagenase relate to the formation of collagen? What is the result of a genetic disorder that results in the deficit of the enzyme collagenase? What is the relationship between collagen, connective tissue and the movement of cells within the extra cellular matrix?

Muscular tissue

Muscular Tissue All muscle cells can contract There are three types Skeletal Cardiac Smooth

Muscular Tissue Voluntary Skeletal Muscle The main type found in mammals Composed of Myofibrils Made up of myofilaments Actin Myosin Responsible for striped appearance

Nervous tissue

Nervous Tissue Has highly developed properties of irritability and conductivity. Composed of packed nerve cells known as neurons.

Epithelial tissue

Epithelial Tissue There are more than 200 visible cell types in the body of a vertebrate Acts as a protective barrier May have complex biochemical functions and secrete specialized products Hormones Milk Tears Absorb nutrients Lining of the gut Detect signals Photoreceptors of the eye Auditory hair cells of the ear Functions of Epithelial Tissue Protective Barrier Biochemical Functions HormonesMilkTears Absorb nutrients Lining of gut Detection of signals Photoreceptors Auditory hair cells

Epithelial Tissue II Epithelial tissue occurs in different forms based. These forms are based on the type of epithelial cells.

Epithelial Tissue III Stratified vs. Simple Cells joined together, side to side, to form multicelluar sheets Thick sheets (many cells) Stratified Epidermis covering of the skin One cell thick Simple Lining of the gut

Epithelial Tissue IV Compound (Stratified Epithelium) Many layers of cells Ones nearest to the basement are normally flattened and dead Impregnated with keratin Found where there is considerable mechanical stress Epidermis of skin Esophagus Anal cavity Vagina

Epithelial Tissue V Cells may be tall Columnar Cells may be cubed shape Cuboidal Cells may be “flat” Squamous

Epithelial Tissue VI Columnar epithelium Tall narrow cells often with cilia Used in transporting mucus and other particles Found in Nasal cavities Trachea Oviducts Ventricles of the brain

Epithelial Tissue VII Squamous epithelium Called “pavement epithelium” Flattened single layer of thin nucleated cells Found where rapid diffusion takes place Bowman’s capsule Alveoli Endothlium

Epithelial Tissue VIII Since epithelial tissue are in the form of sheets, they have two sides (faces) Apical surface Free and exposed to the air or to a watery fluid Basal surface Rests on some other tissue Usually connective tissue Basal lamina The basal lamina (often confused with the basement membrane, and sometimes used inconsistently in the literature, see below) is a layer on which epithelium sits and which is secreted by the epithelial cells. basement membraneepithelium

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