The human alimentary tract consists of a number of specialized structures and modifications.
a) in sequence, describe these structures and their modifications.
Digestion of proteins occurs in stomach and small intestine. Protein containing food stimulate secretion of gastrin from pyloric gland of stomach. It is followed by secretion of Gastrin which stimulates gastric gland for the secretion of HCl, pepsinogen and mucus. Pepsinogen in acidic medicum forms pepsin which digest proteins into proteoses and peptones.