Question

draw a well labelled diagram of human digestive system. with the help of the diagram describe the process of digestion of food in humans.

Answer 1

first  the food enters in our buccal cavity. Here the food is broken down into the small pieces and maxes with sodium and saliva and mucus. the salivary amylase break down the starch into maltose.

the food gets shaped into 'Bolus' and moves down through Oesophagus by peristalytic movement of the muscles.

in the stomach the food remains for 3 to 5 hours. the wall of the stomach realeases gastric juice which contains HCl, Mucus, Enzyme(Pepsin, Renin)

then the liver secretes bile juice which has no enzymess in it. Bile juice makes the medium alkaline. Bile juice emulsifies the fats.

the the pancreas secrete pancreatic juice which has 3 enzymes :- trypsin, pancreatic amaylase, lipase

the glands of small intestine release digestive juices which contain enzymes

the in the small intestine the food nutrients gets absorbed by the villi present in it. then it travels form large intestine where some more nutrients are absorbed and after all the remaining waste gets released by the anus.

Answer 2

■ MOUTH:-

♤ FLUID CALLED SALIVA SECRETED BY THE SALIVARY GLANDS.

♤ THE SALIVA CONTAINS AN ENZYME CALLED SALIVARY AMYLASE.

♤ FUNCTION :- BREAK DOWN STARCH INTO COMPLEX MOLECULE TO GIVE SUGAR.

HELP IN MOISTENS THE FOOD EASY FOR CHEWING AND SWALLOWING

■ OESOPHAGUS:-

♤ THE CANAL HAS MUSCLES THAT CONTRACT RHYTHMICALLY TO PUSH THE FOOD FORWARD & THIS MOVEMENT OF FOOD IS CALLED PERISTALTIC MOVEMENT WHICH OCCURS ALONG THE G.UT.

■ STOMACH:-

♤ GASTRIC GLANDS ARE PRESENT IN STOMACH.

♤ IT RELEASE HYDROCHLORIC ACID (HCL).

♤ FUNCTION:- KILL HARMFUL BACTERIA THAT ENTERS WITH THE FOOD.

MAKES THE MEDIUM ALKALINE.

♤ PEPSIN:- THEY ARE PROTEIN DIGESTED ENZYME.

♤ MUCUS:- PROTECTS THE INNER LINING OF THE STOMACH FROM THE ACTION OF HYDROCHLORIC ACID.

■ SMALL INTESTINE:-

♤ THE EXIT OF FOOD FROM THE STOMACH IS REGULATED BY A SPHINCTER MUSCLE.

♤ IT HELPS IN DIGESTION OF CARBOHYDRATES, PROTEINS AND FATS.

■ LIVER :- IT SECRETE BILE JUICE IN GALL BLADDER.

♤ FUNCTION:- TURN ACIDIC MEDIUM TO ALKALINE.

EMULSIFY THE ACTION OF FAT.

♤ PANCREAS:- IT SECRETE PANCREATIC JUICE IT CONTAIN ENZYME LIKE:-

♤ TRYPSIN :- HELPS IN BREAK DOWN OF PROTEINS.

♤ LIPASE :- CONVERT FAT INTO FATTY ACID AND GLYCEROL.

■ INTESTINAL JUICE:- THE WALL OF SMALL INTESTINE CONTAIN GLAND WHICH SECRETE INTESTINAL JUICE.

♤ FUNCTION :- CONVERT PROTEINS TO AMINO ACIDS.

♤ COMPLEX CARBOHYDRATES INTO GLUCOSE.

♤ FATS INRO FATTY ACIDS AND GLYCEROL.

■ VILLI:- THE INNER LINING OF THE SMALL INTESTINE HAS NUMEROUS FINGER LIKE PROJECTIONS CALLED VILLI.

♤ FUNCTION:- INCREASE THE SURFACE AREA FOR ABSORPTION.

THEY ARE RICHLY SUPPLIED WITH BLOOD VESSELS WHICH TAKE THE ABSORBED FOOD TO EACH AND EVERY CELL OF THE BODY

■ LARGE INTESTINE:-

THE EXIT OF WASTE MATERIAL FROM THE BODY IS REGULATED BY THE ANAL SPHINCTER.