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HumanDigestive

System

Azawiah SadimanAkma Nabila MahyudinNur Fatin Afifah Hashim

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Digestive System

Digestive is the process ofbreaking downfood intosimple molecules that absorbedby the body.

The human alimentary canalstarts from themouth and ends at the anus.

Food moves through the alimentary canal due

to the contraction andrelaxationofmuscles. The movement of the muscles isknown as peristalsis.

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Example Of Peristalsis

Action

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The alimentary canal consist of the mouth,oesophagus, stomach, small intestine(duodenum and ileum), large intestine and

anus.

Organs that are related to the alimental canalare the liver, and the pancreas.

Alimentary Canal

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Liver

LargeIntestine

SmallIntestine

Example Of Human

Digestive System

Anus

Duodenum

Oesophagus

Stomach

Mouth

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MOUTH- Food is chewed into smaller pieces and mixedwith saliva secreted by the salivary glands

- The salivary amylase catalyses the breakingdown of starch into maltose (a kind of sugar)- Saliva also contains mucus.

Human Digestive System

Example ofMouth

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Human Digestive

SystemSTOMACH

- The stomach wall produces gastric juiceswhich

contains proteases and hydrochloric acid.- The hydrochloric acid

::stops the action of salivary amylase. ::provides an acidic medium suitable for

the actionof proteases.

::changes the inactive forms of proteasesto its active

forms.

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- Proteases catalyses the breakdown ofproteins into polypeptides or peptones.

- Mucus protects the stomach walls from beingdigestedby proteases.

- Peristalsis in the stomach walls churns the

food and mixes it with the gastric juices. Thesemi-solid food is called chyme.

Example ofstomach

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LOWER PART OF SMALL INTESTINE-This part of the small intestine secretsintestinaljuice which contains maltase,

proteases and lipase.- Maltase breaks down maltose into glucose.- Proteases breaks down polypeptides intoamino acids.

- Lipase breaks down fats into fatty andglycerol.Example of small

intestine

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DUODENUM-The duodenum is thefirst of the small

intestine. Itreceives bile from the

gall bladder and

Example ofduodenum

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Physical digestion the breakdown of foodsubstances into smaller piecesby the

teeth.

Chemical digestion the chemicalbreakdown of food substances with the aid of

enzymes into simple smaller moleculeswhich can be into the blood circulatorysystem.

Type Of Digestion

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Absorption

ofdigested

food

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The final products of the digestion of foodshown.

The digested products are absorbed through

Absorption of digested food

Class offood

Final product ofdigestion

Starch Glucose , fructose

Protein Amino acids

Fats Fatty acid andglycerol

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The small intestine is adapted for efficientabsorption of digested food by having a largesurface area. This is achieved in the following

ways.- The small intestine is very long. It is about 6metres.- The inner surface of the small intestine has

finger-like projections called villi to increases the

surfacearea for absorption.

- The villus wall is very thinfor the diffusion

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Villus in the wall of the small

intestine

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Transportation of digested food that isabsorbed- Amino acidsand simple sugars(glucose)

areabsorbed through the villus wall into the

bloodcapillaries and transported to the liverby

the bloodvessels.

- Fatty acids andglycerolare absorbedthrough the

villus wall into the lactealsand then into

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Digested food that is carried from the liver isthen transported to the heart. From the heartthe food is distributed throughout the body by

the blood system.

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Tohead

Heart

To the

rest ofthe body

Liver

Smallintestine

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