Tissues

Epithelial Tissues

General Function

act as a barrier

produce secretions (function as glands)

General Anatomical Features

line body cavities, tubes; cover organs

cells are tightly bonded together

contain Germinative cells (cells that undergo mitosis)

connected to underlying tissue by a Basement Membrane

are Avascular (do not contain blood vessels)

Layering and shapes of Epithelial Cells

single layered (Simple and Pseudostratified)

multilayered (Stratified, Transitional)

flat (Squamous), cube-like (Cuboidal), tall (Columnar), oval (seen in Transitional Epithelium)

Classification of Epithelial Tissues

Simple Squamous

cover visceral organs, line body cavities

permit diffusion and filtration

Simple Cuboidal

line exocrine glands, ducts, renal tubules, cover ovaries

permit secretion*, excretion, or absorption

Simple Columnar

line digestive tract

provide protection, permit absorption and secretion*

Pseudostratified Ciliated Columnar

line respiratory airways

provide protection, permit secretion*, ciliary movement

Stratified Squamous

epidermis of skin (keratinized), ends of GI tract (non-keratinized

provide protection

Transitional

line ureter and bladder

permit distension

 

Connective Tissues

General Function

provide structure, support and protection

General Anatomical Features

consist of specialized secretory cells and substances secreted from these cells (the Matrix)

contain fibers composed mainly of Protein

contain a gelatin like substance (Ground Substance)

Classification of Connective Tissues

Fibrous Connective Tissues - matrix produced by Fibroblasts

Loose Connective Tissue - fine collagen fibers, Mast cells

around nerves and vessels, between muscles, in skin

binds organs, holds tissues, permit diffusion

Dense Irregular Connective Tissues - thick collagen fibers

in skin, fibrous capsules of organs and joints

provides strong support in all directions

Dense Regular Connective Tissues - thick collagen fibers

in tendons, ligaments

provides strong support in longitudinal direction

Cartilage Tissues - matrix produced by Chondrocytes

Hyaline Cartilage - thick gelatin matrix

in joint surfaces of bones, nose, respiratory airways

provides flexible support, is a precursor to bone

Osseous Tissues - matrix produced by Osteoblasts - Osteocytes

Bone - calcium phosphate deposits and collagen fibers

in skeleton

provides rigid support, mineral metabolism

Adipose Tissue - composed of Adipocytes that store fat droplets

under skin, around heart, kidneys, eyeballs, joints

provides protection, stores fat, insulates

Muscle Tissues

General Function

cells are specialized to contract

Nervous Tissues

General Function

cells are specialized to transmit signals

 

David G. Ward, Ph.D.  Last modified by wardd 23 May, 2006