'The human digestive system' Grade 7

'The human digestive system' Grade 7

by Tsatsral Ts

​Previous lesson:

​Digestion and absorption

​Digestion is the breakdown of large molecules of nutrents to small molecules, so that they can be absorbed.

Multiple Choice

Most nutrient absorption occurs in the ________________ .

• mouth

• stomach

• large intestines

• small intestines

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​The diagram shows the human digestive system.

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The digestive system is made up of the alimentary canal, plus the salivary glands, liver and pancreas.

​mouth - ам

​salivary gland - шүлсний булчирхай

​oesophagus - улаан хоолой

​liver - элэг

​stomach - ходоод

​gall blander - цөсний хүүдий

​pancreas - нойр булчирхай

​small intestine - нарийн гэдэс

​large intestine - бүдүүн гэдэс

​anus - төгсгөлийн сүв

​Functions of organs in the digestive system

​

Mouth 

Teeth chew food

into smaller pieces. Saliva starts to break down starch to sugar.

​Functions of organs in the digestive system

​

Oesophagus 

Food just passes through here with- out changing.

​Functions of organs in the digestive system

​

Stomach Hydrochloric acid kills micro-organisms in the food. Stomach juices begin to break down protein to amino acids.

​​Functions of organs in the digestive system

​

Small intestine 

Juices from the pancreas finish breaking down starch, protein and fat to small molecules.

These small molecules are then absorbed through the walls of the small intestine. Water, vitamins and minerals (which are already made of very small particles) are also absorbed.

​

​Functions of organs in the digestive system

​

Liver 

The liver makes bile. The bile is stored in the gallbladder.

Bile flows into the small intestine, where it helps with fat digestion.

Multiple Choice

What is the function of the gall bladder?

• storage of bile

• absorption of fat

• digestion of fat

​Functions of organs in the digestive system

​

Pancreas

The pancreas makes pancreatic juice.

Pancreatic juice flows into the small intestine, where  it helps to digest protein, starch and fat.

​Functions of organs in the digestive system

​Large intestine 

All the food that could not be digested and absorbed passes through here.

A little more of the water in it is absorbed. The undigested food collects up and forms faeces.

​Homework

​Workbook, page 21