T I S S U E S

Tissues 4 main tissue types Epithelial Tissue Connective Tissue Muscle Tissue Nervous Tissue Differ in size, shape of cells, amount and kind of fluid between cells & in special function they perform to help maintain body survival Pg 35 Table tissue types & subtypes w/ location and primary function

EPITHELIAL TISSUE Covers body & many parts Lines parts of body Little to no interlocking material so forms continuous sheets that contain NO blood vessels

Epithelial Tissue Classification of shape and arrangement Squamous Cuboidal Columnar simple squamous simple cuboidal simple columnar stratified pseudostratified Pg 37 fig 2-7

Classified by Shape of Cells Squamous  flat Cuboidal  cube Columnar  column Classified by Arrangement of Cells Simple: single layer Stratified: many layers of same shape Transitional: several layers of differing shapes

Simple Squamous Epithelial Cells Fx. Absorption, Diffusion Single layer Scale like Substances pass through easily Ex. alveolar sacs in lungs (gas exchange) Pg 36 fig 2-8 lining of blood & lymphatic vessels

Stratified Squamous Epithelial Cells Fx Protection Several layers Closely packed Ex. Skin surface (epidermis), mucus membranes (prevents cracks, chapping, cuts, etc that decrease protection & allow for invasion of microorganisms Pg 37 fig 2-9 Lining of mouth & esophagus

Simple Columnar Epithelial Cells Fx absorption, secretion ( protection) Line inner surface of stomach, intestines, some respiratory & reproductive tracts Single Layer, higher than wide Nucleoli located towards bottom of cell Openings are special GOBLET cells that produce mucus  moisture/protection Pg 38 fig 2-10

Stratified Transitional Epithelial Cells Fx protection Found in areas subject to stress, able to stretch Ex. Wall of bladder (10 layers of cuboidal cells w/out stretching Expand epithelial sheet when bladder full  decreased cell layers  transitional (change shape  flat Prevents bladder from tearing Pg 38 fig 2-11

Glandular Epithelial Cells Specialized for secretions Function singularly or in clusters called glands Hormones from Thyroid & Pituitary gland  secretions go into ducts, blood, body surface. salivary glands  saliva, digestive juices, sweat, etc,

Simple Cuboidal Epithelial Cells Single layer Cube Shaped Glands, ducts, kidney tubules Limited protection &/or secretion Absorption

Pseduostratified Columnar Epithelial Cells Lining of nasal cavity, bronchi and trachea Protection and secretion cilia

Connective Tissue Most abundant, widely distributed tissue type in body Most varied forms Found in skin membranes, muscles, bones, nerves, internal organs Delicate & thin to hold internal organs together & give them shape Strong & tough cords, rigid bones & blood

Connective Tissue Functions Connects tissues to each other & forms supporting framework for body & organs As blood, transports substances through body Some protect vs microbes

Connective vs Epithelial Tissue Differ in arrangement & variety of cells Amount & kinds of intercellular material (matrix) found between cells Fibers also present

Structural quality & appearance of matrix (intercellular material) & fibers determines qualities or each type of connective tissue Ex. Matrix in blood  liquid Matrix in cartilage  firm rubber Matrix in bone  hard, rigid Matrix in tendons/ligaments  strong, flexible

Major Types of Connective Tissue in Body Areolar Connective Tissue Adipose/Fat Tissue Fibrous Connective Tissue Bone & Cartilage Blood & Hemopoietic Tissue

1. Areolar Connective Tissue Most widely distributed Glue gives form to internal organs Delicate fiber webs Loose matrix of soft sticky gel

2. Adipose or Fat Tissue Specialized to store lipids Many spaces in tissue so FAT can accumulate inside cells Pg 39 fig 2-12

3. Fibrous Connective Tissue Bundles of strong white collagenous fibers in parallel rows Compose tendons Provides strength & non stretching, anchor muscle to bones Pg 40 fig 2-13

4.Bone and Cartilage Bone Matrix Hard & calcified Forms many structural building blocks  Haversian Systems Microscopically, circular arrangements of calcified matrix. Serves as storage area for Ca  support & protection Pg 41 fig 2-14

Cartilage Matrix Matrix firm plastic, gristle like gel Cartilage cells  chondrocytes in tiny spaces throughout matrix Pg 41 fig 2-15

5. Blood & Hemopoietic Tissue Blood: liquid, transport & protective function RBC’s, WBC’s, PLTS, etc Hemopoietic Tissue: found in marrow cavities or bones, organs, spleen, tonsils, lymph nodes Responsible for formation of blood cells & lymphatic system stem cells  important in defense Pg 42 fig 2-16

Muscle Tissue 3 kinds. Specialized in contractions  function that produces many kinds of movements in body

1. Skeletal (striated voluntary muscle) Attaches to bones Cross striations Contractions voluntary Pg 43 fig 2-17

2. Cardiac Muscle (striated involuntary muscle) Composes wall of heart Cross striations Contractions (usually) can’t be controlled Pg 43 fig 2-18

3. Visceral Muscle (nonstriated smooth [involuntary] muscle) Helps form walls of blood vessels, intestines, Cells appear smooth, w/o cross striations Contractions (usually) can’t be controlled pg 44 fig 2-19

Nervous Tissue Function: Rapid communication between body structures & control of body functions 2 kinds of cells Nerve Cells  neurons, functional conducting units of system Neuroglia  special connecting & supporting cells pg 44 fig 2-20 axon dendrites