GENERAL HISTOLOGY

Detailed explanation-1: -Secretion: Epithelial tissue in your glands (glandular epithelium) can secrete (release) enzymes, hormones and fluids. Absorption: The epithelial lining of your internal organs, such as your liver and lungs, can allow the absorption of certain substances.

Detailed explanation-2: -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. They perform a variety of functions that include protection, secretion, absorption, excretion, filtration, diffusion, and sensory reception.

Detailed explanation-3: -Columnar epithelium is mainly involved in absorption and secretion.

Detailed explanation-4: -Absorptive columnar epithelium is characterized as having a striated boarder on its apical side, this border is made up of non-motile microvilli allowing for increase surface area for absorption. These are known as non-ciliated columnar epithelium.

Detailed explanation-5: -The main function of simple columnar epithelial cells are protection. For example, the epithelium in the stomach and digestive tract provides an impermeable barrier against any bacteria that could be ingested but is permeable to any necessary ions. This function is especially important in the colon.