THE EPITHELIAL TISSUE Amal almuhanna Types of Epithelia

THE EPITHELIAL TISSUE Amal almuhanna

Types of Epithelia 1. Covering “surface” epithelium. simple Stratified 2. Glandular epithelium. 3. Neuro_epithium.

Surface “Covering” Epithelium : • Simple Squamous, cuboidal, columnar • Stratified Str. Squamous Str. Cuboida Str. columnar • Pseudostratified columnar

Simple Epithelium : Consists of a single layer of cells, with each layer extending from basement membrane to free surface, ± microvilli. Ø Squamous Ø cuboidal Ø columnar

Simple Epithelium

Stratified Epithelium: • Consists of more than one layer of cells, only one of which is attached to the basement membrane. • Types: Squamous cuboidal columnar

Stratified Sq. Epithelium

Stratified cuboidal Epithelium:

Stratified Col. Epithelium:

Transitional Epithelium: Stratified cells that appear cuboidal when the organ or tube is not stretched and squamous when the organ or tube is stretched by fluid.

Transitional Epithelium:

Pseudo Stratified Epithelium: • Single layer of cells: some tall and thin and reach the free surface + small basal cells. • Nuclei are at different levels (appear stratified). • Cells are almost always ciliated (associated with goblet cells).

Pseudostratified Epithelium:

Classification of Glandular Epithelium: According to : Ø Number of cells. Unicellular & multicellular. Ø Struture of the gland. Simple &branched Ø Mode of secretion. Exocrine & endocrine. Ø Type of secretion. Serous, mucous etc. . Ø Cllular changes after secrtion. Merocine , apocrine and holocrine.

Exocrine Glands • Unicellular

Multicellular Exocrine Glands:

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