The document discusses nutrition and the human digestive system. It describes the five main steps of nutrition in animals as digestion, absorption, assimilation, accumulation, and elimination. It then details the major organs of the human digestive system, including the mouth, esophagus, stomach, small intestine, and large intestine. It provides information on the roles and functions of these organs in digesting and absorbing food.

1. Science
Chapter-2
Nutrition in Animals

2. Nutrition: The process of taking in food by an organism and
its utilisation by the body.
Nutrition in animals takes place in five steps.

4. Digestion in Human beings

5. Human digestive system consists of alimentary canal
and its associated glands.
The main organs of the alimentary canal are:
The Mouth (Oral cavity)
Oesophagus.
Stomach.
Small intestine.
Large intestine.
The associated glands are:
Salivary gland Liver Pancreas

6. Mouth
Food is taken into the body through mouth. It contains teeth,
tongue, salivary glands.
Dental formula for permanent teeth-
Type of teeth Function
Incisors Used for cutting
Canines Used for tearing
Premolars Used for
Chopping
Molars Used for Grinding
and Chewing

7. Tongue helps in-
❑ tasting the food
❑ speaking
❑ swallowing the food
❑ Mixes the food with saliva
❑ making the food soft
Salivary glands secrete watery liquid
called saliva that helps to digest starch
partially.

8. ❖Also known as food pipe
❖Carries slightly digested food from mouth to stomach.
❖Food moves forward by peristaltic movement (Wave
like movement caused by alternate contraction and
relaxation of muscles of alimentary canal)
Oesophagus

10. Stomach
⮚ Thick walled bag present on the left side of the
abdomen.
⮚ Secretes mucous, hydrochloric acid and digestive
juices.
⮚ Mucous protects the inner lining of the stomach from
HCl acid.
⮚ Hydrochloric acid kills the bacteria and makes the
medium acidic that helps digestive juices(enzymes) to
act.
⮚ Digestive juices breaks down protein into simpler
substances.

11. Small Intestine
❑Receives secretions from liver and pancreas.
Besides its walls also secrete digestive juices.
❑Liver secretes bile juice that is stored in gall
bladder before entering small intestine. That
helps in digestion of fats.
❑Pancreas releases pancreatic juice that acts
on carbohydrates, fats and proteins and
converts them into simpler substances
along with intestinal juice.

12. Absorption in Small Intestine

13. Large Intestine
o absorbs back water and any remaining
absorbable nutrients from the food.
o sends the indigestible matter to the
rectum where it is temporarily stored
and thrown out of the body through anus
by the process of egestion.

14. NUTRITION IN AMOEBA