com www.GOALias.blogspot.com www.GOALias ... - fun learning

www.GOALias.blogspot.compartly digested food now reaches thelower part of the small intestine wherethe intestinal juice completes thedigestion of all components of the food.The carbohydrates get broken intosimple sugars such as glucose, fats intofatty acids and glycerol, and proteinsinto amino acids.Absorption in the smallintestineThe digested food can now pass into theblood vessels in the wall of the intestine.This process is called absorption. Theinner walls of the small intestine havethousands of finger-like outgrowths.These are called villi (singular villus).Can you guess what the role of villi couldbe in the intestine? The villi increasethe surface area for absorption of thedigested food. Each villus has a networkof thin and small blood vessels close toits surface. The surface of the villiabsorbs the digested food materials. Theabsorbed substances are transportedvia the blood vessels to different organsof the body where they are used to buildcomplex substances such as theproteins required by the body. This iscalled assimilation. In the cells, glucosebreaks down with the help of oxygen intocarbon dioxide and water, and energyis released. The food that remainsundigested and unabsorbed then entersinto the large intestine.Large intestineThe large intestine is wider and shorterthan small intestine. It is about 1.5 metrein length. Its function is to absorb waterand some salts from the undigested foodmaterial. The remaining waste passesinto the rectum and remains there assemi-solid faeces. The faecal matter isremoved through the anus fromtime-to-time. This is called egestion.2.32.3 DIGESTIONIN GRASSRASS-EATINGANIMALSHave you observed cows, buffaloes andother grass-eating animals chewingcontinuously even when they are noteating grass? Actually, they quicklyswallow the grass and store it in aseparate part of the stomach calledrumen (Fig. 2.9). Here the food getsDiarrhoeaSometime you may have experienced the need to pass watery stool frequently.This condition is known as diarrhoea. It may be caused by an infection, foodpoisoning or indigestion. It is very common in India, particularly among children.Under severe conditions it can be fatal. This is because of the excessive loss ofwater and salts from the body. Diarrhoea should not be neglected. Even before adoctor is consulted the patient should be given plenty of boiled and cooled waterwith a pinch of salt and sugar dissolved in it. This is called Oral RehydrationSolution (ORSORS).NUTRITIONIN ANIMALS1717