Digestive System

If we talk about the digestion:

The process of digestion start from mouth by the action of  mastication.

Mastication is technical form of digestion.below the image of digestive system placed. Please observe  the image then you will study about this system.

 with the help of this image we observe that when a person eat anything like apple the process of digestion start when the apple enter in to the mouth and the process of mastication starts with the contact of saliva which is released by salivary glands contain salivary amylase.

salivary amylase:

this is a enzyme that digest the starch found in food.if we talk about starch or amylum is a carbohydrate consisting of a large number of glucose units joined by glycosidic bonds

after the undergoing of mastication and starch in found in food will be form of small,slurry round, slurry mass called bolus.then it will turned on in to esophagus.

after esophagus stomach has been appeared.

stomach:

After esophagus the main part of digestion has appeared called stomach.This is dilated part of our elementary canal.it has J shaped  and located in the left side of abdomen just beneath the diaphragm.

stomach has two main parts 

1:   cardiac portion

2:   pyloric portion 

                                  Cardiac portion is present immediately after esophagus and pyloric portion is located just beneath the cardiac portion.

here is important point is "sphincters"

stomach has two sphincters number 1 is cardiac sphincter and number 2 pyloric sphincter.

cardiac sphincter is between stomach and small intestine and the bolus enter in to stomach from esophagus through cardiac sphincters.

Food Entrance:

when food enter in to the stomach the gastric glands founds in the stomach walls are stimulates to secret "gestric juice"

the gastric juice is composed chiefly of mucus + hydrochloric acid + water and the most important in which protien digeston enzyme "pepsinogan".

Hydrochloric acid convrt the in_active enzyme pepsinogan in to its active form "papsine"

AND hydrochloric acid also kills microorganisms present in food..Pepsine  partialy digest the pritien portion of food.

Example:

"like a bulk of mutton in to polypeptides and the shorter peptides chain"

IMORTANT TO NOTE :
                                            ONE QUESTION RAISED HERE.......?

Q : Pepsine is powerfull protien digastion enzyme why it is not digest the stomach that is mostly protien ?

ANS: We observe that pepsine not released in its active form it is released in the form of pepsinogan that is inactive and needs Hydrochloric acid for activation. The mucus of gastric juice forms a thick coating  over the inner walls of stomach and neuterlized the HCL there.......
so ! it makes pepsinogan difficult to be activation and attack to stomach walls......