chapter -2 nutrition in ANIMALS

1. The digestive tract and the associated glands together constitute the digestive system

1.1. DIGESTIVE SYSTEM

2. Amoeba is a microscopic single-celled organism found in pond water. Amoeba has a cell membrane, a rounded, dense nucleus and many small bubble-like vacuoles . It pushes out one, or more finger-like projections, called pseudopodia

2.1. FEEDING AND DIGESTION IN ANIMALS

3. The digested food can now pass into the blood vessels in the wall of the intestine. This process is called absorption

3.1. ABSORPTION

4. The inner walls of the small intestine have thousands of finger-like outgrowths. The villi increase the surface area for absorption of the digested food.

4.1. VILLI

5. The absorbed substances are transported via the blood vessels to different organs of the body where they are used to build complex substances such as the proteins required by the body . this is called assimilation

5.1. ASSIMINILATION

6. The faecal matter is removed through the anus from time-to-time. This is called egestion .

6.1. EGESTION

7. The components of food such as carbohydrates are complex substances. These complex substances cannot be utilised as such. So they are broken down into simpler substances. The breakdown of complex components of food is called digestion

7.1. DIGESTION

8. The liver is a reddish brown gland situated in the upper part of the abdomen on the right side. It is the largest gland in the body. It secretes bile juice that is stored in a sac called the gall bladder . The bile plays an important role in the digestion of fats.

8.1. {liver}

9. The grass eating animals quickly swallow the grass and store it in a part of the stomach called rumen (Fig. 2.9). Here the food gets partially digested and called cud but latter the cud returned to mouth in small lumps and the cow chews it . this process is caller rumination and these animal are called ruminants .

9.1. DIGESTION IN GRASS-EATING ANIMALS

10. The pancreas is a large cream coloured gland located just below the stomach . The pancreatic juice acts on carbohydrates, fats and proteins and changes them into simpler forms.

10.1. PANCREAS