Answer:
Step-by-step explanation:
The epithelial tissue covers the body's surface. It originates from all the 3 germinal layers - ectoderm, mesoderm, and endoderm. It presents different parts of the body. It protects different parts from any injury. It also helps in absorption and secretion.
There are 2 types of epithelial tissue - simple epithelial tissue and compound epithelial tissue.
The simple epithelial tissues are single layer cells. These are also different types such as squamous epithelium, cuboidal epithelium, columnar, ciliated and many more.
Squamous epithelial cells: These cells are flat, arrange together without any intercellular space. Simple epithelial cells are present in the outer covering of Bowman's capsule, alveoli of lungs, the lens of the eye.
Cuboidal epithelium: These are cube-like structure as its name suggest. They are secretory in function and present in the pancreas, thymus, etc.
Columnar epithelium: These are cylindrical in structure. The nucleus is present at the base. Such epithelial cells are present in the lining of the alimentary canal, gallbladder, bile duct. Its major function is the absorption of digested food.
Ciliated epithelium: These are simple columnar epithelium having cilia at one end. It is present in the uterine tube, respiratory tract.
Pseudostratified epithelium: The ciliated epithelium sometimes consists of tall and small cells. Many cells do not bear cilia. That's why they are known as the pseudostratified epithelium. It is present in the nasal cavity, trachea, bronchi.
Stratified epithelium: It is one type of compound epithelium. These are present in the epidermis of the skin, the lining of the buccal cavity.