TISSUES I 4 Primary Types A Epithelium B

TISSUES

I. 4 Primary Types A. Epithelium B. Connective tissue C. Nervous tissue D. Muscle II. Epithelial Tissue A. Found in different areas 1. Body coverings 2. Body linings 3. Glandular tissue

B. Functions 1. Protection 2. Absorption 3. Filtration 4. Secretion III. Epithelium Characteristics A. Cells fit closely together B. Tissue always has 1 free surface C. Lower surface is bound by a Basement membrane

D. Avascular (have no blood supply) IV. Classification of Epithelium A. Number of cell layers 1. Simple 1 layer 2. Stratified More than 1 layer

B. Shape of cells 1. Squamous - Flattened 2. Cuboidal Cubeshaped 3. Columnar Columnlike

SIMPLE EPITHELIUM

I. Simple Squamous A. Single layer of flat cells B. Rapid diffusion 1. Lines body cavities 2. Lines lungs and capillaries II. Simple Cuboidal A. Single layer of cube-like cells B. Common in Glands and their ducts C. Forms walls of Kidney tubules

D. Covers the Ovaries III. Simple Columnar A. Single layer of tall cells B. Often includes Goblet cells C. Lines Digestive tract IV. Pseudostratified A. Single layer, but some cells are shorter than others B. Often looks like a double cell layer

C. Sometimes ciliated, like in the Respiratory tract D. May function in Absorption or Secretion

STRATIFIED EPITHELIUM

I. Stratified Squamous A. Cells at free edge are flattened B. Found where friction is common 1. Skin 2. Mouth 3. Esophagus

II. Stratified Cuboidal III. Stratified Columnar A. Surface cells are Columnar B. Lower cells vary in size and shape IV. Transitional Epithelium A. Shape of cells depends on the amount of stretching B. Lines organs of Urinary system

GLANDULAR EPITHELIUM

I. Gland A. 1 or more cells that secretes a particular product B. 2 major gland types 1. Endocrine a. Ductless b. Secretions are hormones 2. Exocrine a. Empty through ducts b. Include sweat and oil glands