Question

explain about epithelial tissue..​

Answer 1

Explanation:

Epithelial tissues are widespread throughout the body. They form the covering of all body surfaces, line body cavities and hollow organs, and are the major tissue in glands. ... Opposite the free surface, the cells are attached to underlying connective tissue by a non-cellular basement membrane.

Answer 2

Answer :

Epithelium tissue -

• It provides a covering or lining for some part of the body.
• The cells are compactly packed with little intercellular matrix.
• The two types of epithelial tissues are simple epithelium and compound epithelium.
• The simple epithelium is composed of single layer of cells. It's function is as a lining for body cavities, ducts and tubes.
• The compound epithelium consists of two or more layers of cells. It's function is to protect just like our skin.
• On the basis of structural modification of cells, simple epithelium is characterized as squamous, cuboidal and columnar.
• The squamous epithelium is made up of single layer of flattened cells with irregular boundaries.
• They are mainly found in the walls of blood vessels and air sacs of lungs.
• They help in diffusion.
• The compound epithelium is composed of a single layer of cube like cells.
• It is mostly found in ducts of glands and tubular parts of nephrons in kidney.
• It helps in secretion and absorption.
• The columnar epithelium is composed of single layer of tall and slender cells.
• The nucleus is located at the base in columnar epithelium cells.
• They are found in the lining of stomach and intestine.
• They help in secretion and absorption.
• Some columnar and cuboidal epithelial cells bear cilia on their surface.
• Of they bear cilia, they are called as ciliated epithelium.
• The function of ciliated epithelium is to move particles, for example, mucus; in a specific direction.
• The ciliated epithelium is mainly present in the inner surface of organs, fallopian tube and bronchioles.
• Some of the columnar or cuboidal cells are also specialised for secretion.
• Such epithelial cells are called glandular epithelium.
• There are two types of glandular epithelium namely unicellular and multicellular.
• The unicellular glandular epithelium tissue consists of isolated gradular cells.
• The example of unicellular glandular epithelium cells is goblet cells of the alimentary canal.
• The multicellular glandular epithelium tissue consists of cluster of cells.
• The example of multicellular glandular epithelium cells is salivary gland.
• The compound epithelium is made of more than one layer of cells.
• It has a limited role in secretion and absorption.
• The main function of compound epithelium is to protect against chemical and mechanical stress.
• They are found a skin, moist surface of buccal cavity, pharynx, inner lining of ducts of salivary glands and of pancreatic ducts.