Tissues

group of similar cells that perform a common function

Types of Tissues

1) Epithelium             * covers body/organ surfaces             * lines body cavities             * forms glands

2) Connective             * binds/supports/protects other tissues and

organs  3) Muscle

            * moves body, materials within body  4) Nervous

            * makes up the nervous system

CHARACTERISTICS OF EPITHELIA Cellularity Polarity

apical surface basal surface

Bound to underlying tissue by a basement membrane Avascularity High regenerative capacity Classified by LAYERS:

1) Simple Epithelium - one layer thick 2) Stratified Ep. - many layers thick

protective function Classified by cell SHAPE:

        1) Squamous - flattened cells         2) Cuboidal - about as tall as they are wide        3) Columnar - taller than wider shaped cells  

Epithelial- GLANDS

Exocrine Glands formed from epithelial tissues- they secrete their materials onto a free surface

A. Unicellular         * one cell         * secrete mucus

B. Multicellular         * secrete materials through a duct

Connective Tissue

CHARACTERISTICS OF C.T. derived from mesenchyme (embryonic CT)

Consists of:         1) Cells         2) Fibers (protein)         3) Ground Substance

CT typically is vascular  

CLASSIFICATION OF C.T.

Connective Tissue Proper Cartilage Bone (Osseous Connective Tissue)

1) Compact                 * outer shell of bone

2) Spongy                 * inner lattice-work of bone                 * houses hemopoietic tissue

Vascular Tissue (Blood)

Muscle Tissue

A. Skeletal Muscle Tissue         * long, cylindrical cells         * multinucleated         * nuclei at periphery of cell         * striations

B. Cardiac Muscle Tissue         * short, cylindrical cells         * some cells are bifurcated (branching)         * has one or two centrally-located nuclei         * intercalated discs         * striations

C. Smooth (Visceral) Muscle Tissue         * spindle-shaped cells         * one centrally-located nucleus