STD 7 SCIENCE Class 7 Science Unit 2 Nutrition in Animals
Buccal Cavity
- The buccal cavity is more commonly known as the mouth, and it is the beginning of the digestive system for humans.
- It consists of the tongue and teeth.
- Teeth: Helps in chewing food and breaking down food into smaller particles.
- Tongue: Fleshy muscular organ attached at the back to the floor of the buccal cavity.
- Saliva is secreted in the mouth and helps in the break down of food.
Tongue
- It is a muscular organ, fleshy in nature attached to the back of the base of the buccal cavity.
- It helps in mixing saliva with food while chewing and aids in swallowing.
- The tongue possesses tastes buds that help us recognise different tastes.
Tooth Decay
- Bacteria present in mouth break down the sugars present from the leftover food and release acid.
- These acids gradually damage the teeth and results in tooth decay.
Oesophagus or food pipe
- The food that is swallowed, passes into the oesophagus.
- It is a muscular tube, about 25 cm long, with a sphincter (valve/opening) at each end.
- Its function is to transport food and fluid, after being swallowed, from the mouth to the stomach.
- Food is propelled down by as there in movement through the walls of the food pipe.
Stomach
- It is a thick-walled bag-like structure.
- It obtains food from the food pipe and opens into the small intestine towards the other opening.
- The inner lining of the stomach produces mucus, hydrochloric acid(HCl)and other digestive juices.
- Food is churned into semi-solid mass in the stomach.
- Enzymes present in the gastric juice disintegrate the food.
- Hydrochloric acid helps in partial digestion of proteins and also kills harmful bacteria.
નીચે આપેલી ગેમ રમી જુઓ મજા આવશે ગમે તો મિત્રો જોડે જરૂર શેર કરજો
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