Question

Explain how the changing form of the mucosal layer affects the function that is performed in each part from oral cavity to anal canal. why it is so important to have villi in the small intestine and stratified squamous in the oral cavity?

Answer 1

Mucosa of oral cavity: It is lined by Stratified squamous epithilia where multiple cells are stacked upon the basal membrane. This multiple layered cell structure helps in protection from the mechanical or chemical abrasion that might generate food. This kind of tissue is always found in regions where the body comes in contact with the outer environment.

Mucosa of Stomach : Stomach is lined by Simple columner epithilium which is unilayered tissue with a number of glands within the cells which produces mucous, enzymes, hormones etc. This helps in breakdown of the food paricles.

Mucosa of small intestine: It is also lined by simple columner epithilium with specialised absorptive cells. This epithilium is arranged in finger like projections known as villi which increases total absorption area to ensure maximum absorption. All the nutrients in its simple form gets absorbed here and mixes with the blood.

Mucosa of large intestine: It is also lined by simple columner epithilial cells but are not arranged in villi formation. Some epithilial cells secretes mucous to lubricate the intestinal wall to protect from rough food remains.

Mucosa of anal canal: Anal canal has 3 parts. The innermost part is lined by simple columner epithilium. The middle and outermost part is covered by non keratinized stratified squamous epithilium and keratinized squamus epithilium to protect it from abrasion. Keratin is a hard covering which gives extra protection at the outer most region.