Digestive System

Digestive system

·Key Vocabulary

-Pancreas

-Liver

-Alimentary canal

-Pharynx

-Churning

-Enzymes

-Chyme

-Duodenum

-Bile

-Gall bladder

-Faeces

-Pancreatic juices

-Slurry

-Fermenting vat

Q1) Where do we get the energy from?

 Ans)Food we eat

Q2) How do you think the food we eat provides us energy?

Ans) When the food is digested, it produces energy in our body, that is used for performing various tasks.

 Q3) When you eat an apple, what happens to the apple?

Ans) We chew it in our mouth and then swallow it.

Q4) What happens after you chew the apple?

Ans) It becomes soft and is ground into  fine particles then as we swallow it, it moves into our throat.

---The food is cut, chewed and broken into smaller pieces in the mouth,  

---Thereafter it enters the oesophagus and then into the stomach,

---From the stomach the food travels to the small intestine collecting chemicals  from liver and pancreas for digestion,  

---After the digestion in the small intestine the undigested food, travels through the large intestine and is finally excreted through the anus.

---The liver and pancreas aid in digestion and thus form the part of the digestive system.

The length of each organ of the alimentary canal:  

3 inches= Mouth

10 inches= Oesophagus

6 inches= Stomach  

18 feet= Small intestine

5 feet Large intestine
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Q5) What are the organs through which the food passes during the process of digestion?

Ans) Mouth,oesophagus, stomach, small and large intestine.

Q6)   Where do you think does the food is digested?

Ans) In the stomach.

Q7) What do you feel when you think about all these food items?

Ans) Feel hungry, want to eat atleast one of them, etc.

Q8)  Do you feel anything in your mouth when you think about the food?

Ans) Yes, the mouth turns watery.

Q9)  What do you think is this watery liquid in your mouth?

Ans) Saliva.

Q10) What happens to the food when you put it into your mouth?

Ans) The food gets mixed with the saliva.

Q11) Why do you think the saliva is secreted when we chew food?

Ans) To soften the food so that it becomes easy to swallow.

Q12) Do you think that the saliva plays any role in the digestion process? (yes/no)

Ans) The saliva in the mouth produces enzymes and initiates the primary process of digestion of food.

Thus one can say that the digestion process starts in the mouth itself. Later as the food travels through the oesophagus and reaches the stomach, stomach produces other digestive juices that help in further digestion of food.

---The process of digestion that takes place in the mouth, oesophagus and the stomach.

---The organs of our digestive system produce chemical substances known as enzymes that help in digestion of foods.

Enzymes are special type of proteins that help in digesting food.

Location- Mouth (saliva)

 Enzyme- Salivary amylase

Substrate- Starch

Location- Stomach (gastric juices)

 Enzyme- Pepsin

Substrate- Proteins

Substrate means the material or substance in the food consumed, on which an enzyme acts

---Maltase,lactase,sucrose is forms of glucose which are released as the complex carbohydrate molecule is broken down in the digestion process.

Q13) Where is saliva produced?

Ans) Salivary glands.

Q14)  Which enzyme is released in the saliva?

Ans) Salivary amylase.

Q15)  What substrate does this enzyme act on?

Ans) Starch.

Q16)  What happens to the food in the oesophagus?

Ans) The food is only churned and pushed to the stomach through a wave like action- peristalsis.

 Q17) What happens to the food in the stomach?

Ans) Gastric juices release enzymes to  digest proteins form the food and emulsify the food to form smooth slurry.

---The food is passed on to the small intestine in the duodenum the liver and pancreas secrete more enzymes- bile and pancreatic juices respectively; that help in digestion of fats from the food.

---The process of digestion ends in the small intestine (duodenum).

---No digestive juices or enzymes are produced by the small or large intestine.

---In the large intestine only absorption of water takes place.

---The major role of the intestine is to absorb the nutrients from the digested food and pass it in the blood stream.

---After the water is absorbed in the intestine the undigested food is stored in the rectum and eventually is excreted through the anus as faeces.
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Location - Duodenum (pancreatic juices)

Enzyme- Trypsin Lipase

Substrate- Carbohydrates Fats

Location - Ileum (intestinal juices)

Enzyme- Peptidase

Substrate- Remaining carbohydrates and proteins

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Q18)How do we get energy?

Ans) When food is digested it provides us with energy.

Q19)  How does the body get the required nutrients?

Ans) As the food gets digested the nutrients are absorbed such as proteins, carbohydrates, fats and they provide us with the required energy.

Q20)  What exactly does the digestion process mean?

Ans) Breaking down the  consumed food into smaller particles and absorbing the nutrients from the food.

---The ill effects of unhealthy eating habits on the health:

---Eating while walking

---Eating unhealthy/junk/fast food

---Sleeping while eating

---Eating in uneven intervals in a day

---Road side food

---Canned/ packaged food

--- Value: Packaged/canned food is not just harmful for our health, but it is equally harmful for the environmental health too.

---Canned/Packaged food creates loads of plastic waste in the dumping grounds.

--- Road side food can lead to epidemic disease spreads.

--- Producing the ingredients used to prepare the junk/fast food takes lot of  energy and natural resources compared to the yield.

Q21) How do you think eating fast food such as chips or fries is harmful for our health?

Ans) Such food products contain lots of salt, oil, preservatives and fats that are not good for our health and causes obesity in teenagers especially.

Q22) Why do you think packaged food products cause damage to the environment too along with human health?

Ans) Consuming more and more packaged food leads to more and more garbage generation; thus a large space for dumping this waste is required. Also dumping such waste in dump yards leads to many disease spreads in the nearby areas and causes soil pollution too.