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NUTRITION IN

HUMAN BEINGS

PREPARED BY : REKHA CHOUDHARY

T.G.T (SCIENCE) K.V. VIKASPURI

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LEARNING OBJECTIVES

  • DEFINE DIGESTIVE SYSTEM
  • TELL THE PARTS OF ALIMENTARY CANAL
  • DRAW A WELL LABELLED DIAGRAM OF HUMAN DIGESTIVE SYSTEM
  • LEARN HOW NUTRITION TAKES PLACE IN HUMANS
  • EXPLAIN DIGESTION IN GRASS EATING ANIMALS.

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RECAPITULATION

NUTRITION IS A COMPLEX PROCESS INVOLVING –

  • INGESTION
  • DIGESTION
  • ABSORPTION
  • ASSIMILATION
  • EGESTION

The process of taking food into the body is called Ingestion

THE BREAKDOWN OF COMPLEX COMPONENTS OF FOOD INTO SIMPLER SUBSTANCES IS

CALLED

DIGESTION.

ABSORPTION IS THE PROCESS BY

WHICH THE PRODUCTS OF DIGESTION ARE

ABSORBED BY THE BLOOD TO BE SUPPLIED TO ALL PARTS OF THE BODY.

ASSIMILATION IS THE PROCESS IN WHICH ABSORBED FOOD MATERIALS ARE CARRIED BY THE BLOOD TO DIIFERENT PARTS OF THE BODY AND USED BY THE BODY.

EGESTION IS THE PROCESS IN WHICH UNDIGESTED AND UNABSORBED FOOD IS DISCHARGED FROM THE BODY.

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NUTRITION

IN

HUMANS

  • INGESTION
  • DIGESTION
  • ABSORPTION
  • ASSIMILATION
  • EGESTION

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INGESTION

FOOD IS TAKEN INTO THE BODY THROUGH MOUTH.

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WHAT HAPPENS TO THE FOOD INSIDE THE BODY?

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Food inside our body passes through a canal known as Alimentary Canal.

DIGESTIVE TRACT

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-Buccal cavity

-Oesophagus

-Stomach

-Small Intestine

-Large Intestine

-Rectum

-Anus

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-SALIVARY GLANDS

-LIVER

-PANCREAS

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DIGESTIVE SYSTEM

Digestive Tract with Associated Glands

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TASK

1.BUCCAL CAVITY

2.OESOPHAGUS(FOOD PIPE)

3.STOMACH

4. PANCREAS

5. SMALL INTESTINE

6. LARGE INTESTINE

7. LIVER

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DIGESTIVE SYSTEM

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TASK

IDENTIFY THE FOLLOWING PARTS OF HUMAN DIGESTIVE SYSTEM

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DIGESTION

-MECHANICAL

-CHEMICAL

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DIGESTION

MECHANICAL DIGESTION BREAKS FOOD INTO SMALLER PIECES.

IT TAKES PLACE IN MOUTH WITH THE HELP OF TEETH.

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EACH TOOTH IS ROOTED IN A SEPARATE SOCKET IN THE GUMS.

OUR TEETH VARY IN APPEARANCE AND PERFORM DIFFERENT FUNCTIONS.

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HAVE YOU HEARD THE NAMES OF MILK TEETH AND PERMANENT TEETH?

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DIGESTION

OUR MOUTH HAS SALIVARY GLANDS WHICH SECRETE SALIVA.

SALIVA CONTAINS SALIVARY AMYLASE ENZYME BREAKS DOWN THE STARCH INTO SUGARS.

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TONGUE

FLESHY MUSCULAR ORGAN IN BUCCAL CAVITY.

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WE USE OUR TONGUE FOR TALKING.

TONGUE MIXES SALIVA WITH THE FOOD.

TONGUE HELPS IN SWALLOWING OF FOOD .

WE TASTE FOOD WITH OUR TONGUE.

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WHEN THE FOOD BECOMES SOFT MASS, TONGUE PUSHES IT TO THE FOOD PIPE

(OESOPHAGUS)

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WHEN YOU EAT IN A HURRY, TALK OR LAUGH WHILE EATING, YOU MAY COUGH, GET HICCUPS OR A CHOKING SENSATION.

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THIS HAPPENS WHEN FOOD PARTICLES ENTER THE WINDPIPE .

INSIDE THE THROAT, AIR AND FOOD SHARES A COMMON PASSAGE.

HOW IS FOOD PREVENTED FROM ENTERING THE FOODPIPE?

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DURING THE ACT OF SWALLOWING, A FLAP LIKE VALVE KNOWN AS EPIGLOTTIS CLOSES THE PASSAGE OF WIND PIPE AND GUIDES THE FOOD INTO THE OESOPAGUS( FOOD PIPE ).

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THE OESOPHAGUS IS A LONG TUBE THAT RUNS FROM THE NECK TO CHEST.

FROM OESOPHAGUS, FOOD ENTERS INTO THE STOMACH.

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DIGESTION

STOMACH IS THE WIDEST PART OF ALIMENTARY CANAL.

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DIGESTION

FOOD IS CHURNED AND MIXED

WITH DIGESTIVE

JUICES SECRETED BY

GASTRIC GLANDS

WHICH INCLUDES

PEPSIN ENZYME,

HYDROCHLORIC

ACID AND

MUCOUS.

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DIGESTIVE

JUICE

DIGESTION

MUCOUS PROTECTS THE LINING OF STOMACH.

ACID KILLS MANY BACTERIA AND ACTIVATES PEPSIN ENZYME.

PEPSIN ENZYME BREAK DOWN THE PROTEINS INTO SIMPLER SUBSTANCES.

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IN STOMACH, FOOD CHANGES TO CHYME AND THEN MOVES TO THE SMALL INTESTINE.

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SMALL INTESTINE IS LONGEST PART OF OUR DIGESTIVE SYSTEM.

7.5 metres

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Its wall also secretes digestive juices, and receives secretions from Liver and Pancreas.

DIGESTION

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Liver is the largest gland in the body.

Liver secretes bile juice.

Bile juice is stored in a sac like structure called Gall Bladder.

Bile juice helps in the emulsification of fats.

DIGESTION

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Pancreas secretes pancreatic juice which contains lipase and trypsin enzyme.

Trypsin helps in digestion of proteins and lipase helps in digestion of emulsified fats.

DIGESTION

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THE INTESTINAL JUICE COMPLETES THE DIGESTION OF ALL COMPONENTS OF FOOD.

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DIGESTION

CARBOHYDRATES

GLUCOSE

FATS

FATTY ACIDS AND GLYCEROL

PROTEINS

AMINO ACIDS

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ABSORPTION

There are tiny finger like projections called Villi present on the surface of small intestine.

ABSORPTION OF DIGESTED FOOD MATERIAL TAKES PLACE IN SMALL INTESTINE.

IT INCREASES THE SURFACE AREA FOR THE ABSORPTION OF DIGESTED FOOD.

THE SURFACE OF VILLI ABSORBS THE DIGESTED FOOD MATERIALS.

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ASSIMILATION

THE ABSORBED SUBSTANCES ARE TRANSPORTED TO DIFFERENT ORGANS OF THE BODY VIA BLOOD.

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Absorption of water and some salts out of undigested food takes place in Large Intestine.

This is important because recovering of water keep us safe from getting dehydrated.

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EGESTION

SOLID WASTES MOVE TO THE LAST PART OF LARGE INTESTINE CALLED THE RECTUM

THE FAECAL MATTER IS REMOVED THROUGH THE ANUS.

THIS PROCESS IS CALLED EGESTION.

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PREPARED BY – REKHA CHOUDHARY

T.G.T SCIENCE

KENDRIYA VIDYALAYA

VIKASPURI

THANKYOU