How does digestion work?

Digestion is the process by which food is broken down into its smallest parts, which can then be absorbed into the bloodstream and used by our bodies to grow, repair, and function.

How do we digest food?

Mechanical
Food is broken down in the mouth by our teeth as we chew.
The mouth also contains saliva, which is a watery fluid that moistens and lubricates the food.
Saliva also contains amylase, which is a digestive enzyme that starts breaking down starches in the food.
The swallowing reflex moves food into the oesophagus, where involuntary muscle movement called peristalsis moves the food down into the stomach.

Chemical
Within the stomach the food is churned and mixed with gastric juice, which is produced by cells within the stomach lining.
Gastric juice is highly acidic, and also contains enzymes which start to break down the protein in the food, eventually reducing it to a creamy paste known as chyme. At the bottom of the stomach, the chyme moves into the small intestine, or duodenum.
Juices from the pancreas and bile from the liver enter the duodenum and help to lubricate the partially digested food as it moves through the gut. Large molecules within the chyme are broken down into small molecules so that they can be absorbed into the bloodstream.
The enzymes that we use to break down food are made in our cells, and we make different ones to break down specific types of food, for example – carbohydrates or proteins.

Absorption
The small intestine is where nearly all of our food is absorbed into our body. Once broken down into smaller molecules, the nutrients can be absorbed through villi, which are tiny structures shaped like fingers protruding from the lining of the small intestine.
Villi increase the available surface area so that as many molecules as possible can be absorbed and carried into the bloodstream.

Elimination/Egestion
By the time the digested food products have reached the end of the small intestine, most of the useful nutrients have been removed, and only indigestible elements remain.
The large intestine removes water, and forms and stores the faeces. A large amount of bacteria (more than 500 species) are present in the large intestine. These help to recover any remaining nutrients from the food, and also make some vitamins – such as Vitamin K – for the body to use.

As undigested material accumulates in the rectum, it stimulates a response that leads to the evacuation of the waste through the anus.
How do we get energy from food?

Once food is broken down by the digestive process and enters the bloodstream, the molecules from the nutrients it contained travel in the blood to every cell. Inside the cells, they are used to give us energy, as well as to grow and maintain our bodies.

1. Who is the main person or group of people in this news article?

2. What was the key event from the news article?

3. Where did this event take place?

4. When did this event take place?

1. Find a quote from the main person in this news article?

2. In your own words describe what happened in this news article.

3. Find out where this event took place and include some information about this place.

4. Tell us when this event happened and explain what might happen in the future.

5. Explain in your own words why this event took place.

Current Events Web
Find the Who, What, Where, When, How and Why in the article to complete this worksheet.

I Think Because
Share what you think about the article and explain why.

My Questions
Write a question map about questions that you have after reading the article.

News Review
Give the news article you have read a review

KWL
Write what you KNOW about the topic in the article, what you would LIKE to find out and then what you have LEARNT.

Newspaper Bingo
Play newspaper bingo. Find a number of different articles to complete the grid.

Questions and Answers
Write a set of questions and then their answers after reading the article.

The Big Idea
Find the big idea by highlighting the 5 W’s and 1 H. then select 25 of key words associated with the article.

Word Investigation
Vocabulary exercise where students find key words within the article.

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Goats Rule ;D
Goats Rule ;D
2 years ago

Wow :O

Michael
Michael
2 years ago

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kaka
kaka
2 years ago

yo this is cool as

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