In: Biology
– Take one part of the digestive tract (not esophagus) or a major accessory gland (liver or pancreas), describe its structure and makeup (diagrams are helpful), cell types that are important for digestion (excretions etc..) and what happens within this part of the digestive tract or the purpose of the accessory organ?
I am considering the stomach which has four part like cardia which is beneath the oesophagus is cardia because this part is situated beneath heart.
Then the upper inflated part is called fundus.
Then the middle large position which is called body .
And the last most position is called pylorus.
Stomach has 4 layers from outside to inner side ..
Serosa layer, muscular layer, submucosa layer and mucosa layer.
The stomach has two types of gland which has many other cells ehich secretes many enzymes or mucus which helps in digestion .
Stomach has many cells like parietal cell, chief cells ,goblet cells and D and G cells.
Parietal cells secretes hydrochloride acid which helps to activate and main protein digesting enzymes and it also kill bacteria or other organisms inside stomach.
Chief cells secrete pepsinogen which after becoming activated ,pepsin which digest protein into peptides.
Goblet cells secretes mucus which makes the stomach from excoriation by acids.
D cells secrete somatostatin which inhibit acid secretion whenever needed.
G cells secretes gastrin which stimulate acid secretion whenever needed.
it is the gastric gland and the cells is present throughout their length and in various positions various cells are present.