DIGESTIVE SYSTEM OF MAN PART 2

5) STOMACH:-

Anatomy:

Human stomach is a muscular sac organ which consist of 3 parts.

*Cardiac part:-

The upper muscular narrow pipe like structure is called Cardiac sphinctor.

*Middle part:-
Middle part is known as Fundus which secretes digestive enzyme.

*Pyloric part:-
The lower part which is connected with duodenum. This part contain valve called Pyloric sphintor.

Physiological function:-

It forms a covering on wall of stomach.

1-Mucus: To protect from the action of enzyme.

2- HCL: It kills bacteria and germs provide acidic mediam for the action of enzyme.

Complex protein polymer --HCL--> simple protein

3-Pepsinogen:-

It is an inactive enzyme which is changed into pepsin enzyme by the help of HCL.

Protein ---pepsin--> peptones

4-Renin:-

It is present in infants and babies .

Milk-----renin--> curd

Chyme formed into duodenum.

6)SMALL INTESTINE:-

Anatomy:-
Largest part in G.I.T. Its consists of 03 parts as.

Physiology:-

a) Duodenum:- 

The stomach open into duodenum .It is a very important part receives bile duct from liver and pancreatic duct from pancreas. Both open in duodenum called Bilo pancreatic duct.

Function of bile:-

*Basic compound scretes sodium carbonate.

*It acts on fat and emulsify it .

Function of pancreatic juice:-

*Trypsinogen:

Peptones----trypsin--> polypeptide

*Amylase:

Carbohydrates ----amylase---> diasaccharides

*Lipase:

Fats----lipase--> fatty acid + glycerol

*Chymotrypsin:

Milk protein (casein) ----chymotrypsin--> amino acid

b) JEJUNUM:- 

*Erypsin:-   Polypeptide -----erypsin--> amino acid

*Maltase:-

Maltose ---Maltase--> glucose

*Lactase:-

Lactose ---lactase--> galactose + glucose

*Sucrose:-

Sucrose ------> glucose

*Lipase:-

Fats --------> fatty acid + glycerol

c) ILEUM:-

In the ileum absorbtion of digested food takes place . In the ileum there are small projection known as villi.The villi are consists of epithelial cell and lacteals which are special cells and connected with lymph vessels villi also have blood capillaries.

Function:-

*The glucose and amino acid absorbed by villi.

7) LARGE INTESTINE:-

Anatomy:-

Large intestine consist of following 3 parts:-

1;Caecum:
In this part special bacteria are present which help in digestion of cellulose. It is converted into sugar then its absorbed in body.

2;Colon : consist if three parts

a) Ascending part                    b)Transverse part              c) Descending part  

Physiological functions:-

*Inorganic salts,vitamins and water are absorbed in colon.

*Assimilation of excretory substance takes place in large intestine .

8) Rectum:-

In the rectum purely undigested food comes and it is expelled periodically out of body through anus after the reabsorbtion of water.