Question

2. Explain the differences between the layers of the gastrointestinal tract. (0.5 points)

Answer 1

In mammalian alimentary canal we can see four layers (almost in all organs in gastrointestinal tract) with minor and major differences in different organs. These layers are named as:

1.     Serosa (Outermost layer)

2.     Muscularis propria (made up of muscles)

3.     Sub-mucosa (comparatively thin layer)

4.     Mucosa (also having some sub-layers including epithelium lining and loosely arranged cell and glandular or secretory cells)

In the stomach the thickest layers can be observed with lots of secretory cells like secretion of enzymes and HCl for microbial activity and maintenance of acidic environment. In case of small intestine more absorptive cells are present in the mucosa for absorption of nutrients like amino acids, glucose and fatty acids. And numerous blood capillaries compared to rest of the gastrointestinal tract. Similarly, different layers are present in the large intestine and the rectum also.