the digestive system in humans

7/30/2019 The Digestive System in Humans

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The complex molecules cannot

be used by body cells unless

they are broken down into

simpler molecules first.

Only these simpler molecules

can be readily absorbed or usedby the cells in our body.


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The process of breaking down

large complex food molecules

into smaller and simpler form is

called digestion.

These molecules are soluble and

can be readily absorbed by thebody.


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Digestion takes place in the

digestive system which consists of the

alimentary canal , glands and organsthat digest food.


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Human Anatomy, 3rd editionPrentice Hall, 2001

Overview of Digestive System


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The digestive system in

humans

Filling in the blanks.1. _______ is the process in which

food is broken down into ______

molecules which can be used bythe body cells.

2. Digestion takes place in the ____

______ which consists of the ____, __________ and ___ that digest

food.


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3.The alimentary canal starts withthe ____ and ends with the ____.

4.Glands and organs in thedigestive system included the

_____ glands, ___ , ____ ____and ______.

5. ______ helps move the food

along the alimentary canal.6. Digestion involves both ____ and

____ processes.


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7.Physical digestion is done by the_____.

8. Chemical digestion is done byusing specific ________.

9.The end product of carbohydratedigestion is _____. Fat isdigested to become ___ ____

and ______. Protein becomes___ ____.


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10. The products of digestion areabsorbed into the blood stream

from the ____ _____.11. The digestive process iscompleted in the ____ ____.

Th di ti t i


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humans

Filling in the blanks.1. Digestion is the process in which

food is broken down into simpler

molecules which can be used bythe body cells.

2. Digestion takes place in thedigestive system which consistsof the alimentary canal , glandsand organs that digest food.


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3.The alimentary canal starts withthe mouth and ends with the

anus.4.Glands and organs in the

digestive system included thesalivary glands, liver , gallbladder and pancreas.

5. Peristalsis helps move the foodalong the alimentary canal.

6. Digestion involves both physical

and chemical processes.


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7.Physical digestion is done by theteeth.

8. Chemical digestion is done byusing specific enzymes.

9.The end product of carbohydratedigestion is glucose. Fat isdigested to become fatty acids

and glycerol. Protein becomesamino acids.


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10. The products of digestion areabsorbed into the blood stream

from the small intestine.11. The digestive process iscompleted in the small intestine.


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Salivary gland

stomach

duodenum

Small

intestine

large

intestine

anus

rectum

duodenum

pancreas

liver

oesophagus

mouth

Th di ti t i


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humans

Th di ti t i


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humans

Salivary amylase is produced bythe salivary gland.

salivary amylase(enzyme)

Starch maltose

(sugar)

Mouth--Food is chewed andphysically broken down by theteeth.


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Enzymes are

special proteins

produced by thebody to speed

up chemical

reactions in our

body.


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oesophagus

Peristalsis : a wave- like movement that movesfood in the digestive system especially inthe oesophagus and the intestines.

Food is moved from the mouth tothe stomach, through the actionofperistalsis.

It is caused by the continuouscontraction and relaxation of the

muscles along the alimentary canal.


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peristalsis


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stomach

Gastric juices have hydrochloricacid and enzymes.

Gastric glands produce gastricjuices.

hydrochloricacid kills bacteriaand stop the action of salivary

amylase.


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stomach

pepsin

Protein peptones

Enzymes: pepsin and renin

renin

Liquid milk solid milk

proteins proteins


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stomach


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stomach

Duodenum first part of the


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Duodenum

first part of the

small intestine

Bile is produced by the liver and it isstored in the gall bladder.

The duodenum receives bile andpancreaticjuice

Functions:

Emulsification of fats

Alkaline medium


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Duodenum

pancreaticjuice is produced bypancreas.

Contains:

Pancreatic amylase

pancreatic protease

pancreatic lipase


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Duodenum

Pancreatic amylase

Starch maltose

Pancreatic protease

peptones amino

acids

Pancreatic lipasefat fatty acids +

glycerol


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Small intestine


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Small intestine(ileum)secretes

intestinal juices which contain

enzymes.maltase

maltose glucose

protease

peptones amino acids

lipase

fat fatty acids +

glycerol


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small intestine

Digestion is completed.

Digested food is absorbedthrough the thin walls of thesmall intestine into thebloodstream.


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Large intestine (colon)

reabsorption of water

Formation of feaces


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Rectum

Stores feaces


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the digestive system in humans

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