Digestive system
·Key Vocabulary
-Pancreas
-Liver
-Alimentary canal
-Pharynx
-Churning
-Enzymes
-Chyme
-Duodenum
-Bile
-Gall bladder
-Faeces
-Pancreatic juices
-Slurry
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
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.