give characteristics and types of the epithelial tissue.
Answers
Answer:
Characteristics of epithelial tissue:
i. Epithelial tissue covers the body outside and lines the various cavities inside.
ii. Epithelial tissue lines the hollow organs, body cavities, blood vessels and ducts.
Epithelial tissue originates from all the three primary germ layers, i.e. ectoderm,endoderm and mesoderm.
iv. Cells of an epithelial tissue are compactly arranged and having a very little or no intercellular space is seen. They form a continuous sheet.
v.Cells are rested on thin, doubled layered, non-cellular basement membrane.
vi. Epithelial tissue has nerve supply of its own.
vii. Epithelial tissue is avascular (a without, vascular = vessel), i.e. it lacks its own blood supply and hence, obtains nutrients which diffuse out of blood vessels.
viii. Epithelial tissue has the power of division and regeneration. The old injured dead cells are sloughed off regularly and are replaced by new ones.
Types of Epithelial tissue:
It is classified into:
1. Simple epithelium:
Epithelial tissue which is only one cell thick is known as simple epithelium.
It is further classified into:
a. Simple Squamous Epithelium
b. Simple Columnar Epithelium
c. Simple Cuboidal Epithelium
d. Simple Ciliated Epithelium
e. Simple Glandular Epithelium
2. Compound or Stratified epithelium:
Epithelium composed of several layers is called compound epithelium or stratified epithelium.