Classify and describe epithelial tissue on the basis of structural modifications of cells.
Epithelial tissues can be divided into three types on the basis of structural modifications of cells. namely squamous. cuboidal and columnar
Squamous Epithelium: This type of epithelial tissue is made up of a single thin layer of flattened cells. The cells in this tissue have irregular boundaries. This type of epithelium is found in the walls of blood vessels and in air sacs in the lungs. The thin layer makes a diffusion boundary and thus facilitates diffusion of substances,
Cuboidal Epithelium: This type of epithelial tissue is composed of a single layer of cuboidal cells. This type of issue is found in the ducts of glands and in the nephron. Secretion and absorption are the main functions of the cuboidal epithelium.
Columnar Epithelium: This type of tissue is composed of a single layer of tall and slender cells. The nuclei of cells are located at the base. Microvilli may be present at the top of cells. This type of tissue if found in the lining of the stomach and intestine. The main function is secretion and absorption.
Ciliated Epithelium: If cilia are present on the cuboidal or columnar epithelium, they are called the ciliated epithelium. In that case, the movement of substances is their main function. Ciliated epithelium is found in bronchioles and fallopian tubes.