Animal TissuePacket #52

Chapter #40

Introduction

Animals are predators and must be strong and agileMeans 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 tissueAnimal Tissue

Connective Tissue ICharacteristics

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 IIFunctions

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 IVCollagen

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 mammalMore than any other type of protein

Collagen is long, stiff and a triple stranded helical structureCollagen fibrils

10-300nm in diameter

Connective Tissue VCollagen

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

Epithelial Tissue II

Epithelial tissue occurs in different forms based.

These forms are based on the type of epithelial cells.

Epithelial Tissue IIIStratified 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.

Review