The Digestive System-nutrition

8/14/2019 The Digestive System-nutrition

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THE DIGESTIVETHE DIGESTIVE

SYSTEMSYSTEM


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Dig est io nig est io n The process whereby food is broken downThe process whereby food is broken down

into smaller parts, chemically change andinto smaller parts, chemically change and

moved into the gastrointestinal system.moved into the gastrointestinal system.


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Mechanical DigestionMechanical Digestion

Food is broken down into smaller piecesFood is broken down into smaller pieces

by the teethby the teeth It is then moved along theIt is then moved along the

gastrointestinal tract through thegastrointestinal tract through the

esophagus, stomach and intestinesesophagus, stomach and intestines Movement is caused by rhythmicMovement is caused by rhythmic

contraction of the muscular walls of thecontraction of the muscular walls of the

tracttractPERISTALSISPERISTALSIS


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Chemical digestionChemical digestion

Chemical changes occurs through theChemical changes occurs through the

addition of water and the resulting splitting,addition of water and the resulting splitting,

or breaking down of the food molecules.or breaking down of the food molecules.

HYDROLYSISHYDROLYSIS

Hydrolysis involves digestive enzymes actHydrolysis involves digestive enzymes act

on food substances, causing them to breakon food substances, causing them to break

down into simple compoundsdown into simple compounds


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Dig est io n in t he Mo uthig est io n in t he Mo uth Teeth and tongue begin digestion byTeeth and tongue begin digestion by

breaking food into smaller piecesbreaking food into smaller pieces

Salivary Glands begi chemical digestion asSalivary Glands begi chemical digestion as

salivary amylase begins to change starch tosalivary amylase begins to change starch toDextrin and MaltoseDextrin and Maltose


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Dig est io n in t heig est io n in t hestomachtomach Hydrochloric acid prepares the gastricHydrochloric acid prepares the gastric

area for enzyme actionarea for enzyme action

Pepsin,Pepsin, produced first as inactiveproduced first as inactive

precursorprecursorto pepsinogen, then activatedto pepsinogen, then activated

by HCLby HCL

In infants,In infants, enzyme Rennin casein toenzyme Rennin casein to

coagulatedcoagulated curd (breaks milk protein)curd (breaks milk protein)

Lipase actsLipase acts on emulsified fatson emulsified fats

TributyrinaseTributyrinase


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Digesti on on the Smalli gesti on on the Smallintesti nentesti neproduces bileproduces bile

stores bile and releases it intostores bile and releases it into

small intestine to emulsify fatssmall intestine to emulsify fats

Produce enzymes, then areProduce enzymes, then arereleased into the small intestinereleased into the small intestine


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Carbohydrates:Carbohydrates:

Pancreatic Amylase AMYLOPSINPancreatic Amylase AMYLOPSIN

Converts starch to dextrin and MaltoseConverts starch to dextrin and Maltose

Intestinal Juices that contain enzymes:Intestinal Juices that contain enzymes:

Lactase, Sucrase and MaltaseLactase, Sucrase and Maltase

Converts disaccharide toConverts disaccharide to

monosaccharidemonosaccharide


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FatFat

Pancreatic lipase turn triglycerides toPancreatic lipase turn triglycerides to

digyceride and monoglyceride to fattydigyceride and monoglyceride to fatty

acids and glycerolacids and glycerol

Bile Salt emulsifies fatsBile Salt emulsifies fats


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ProteinProtein

Pancreatic Proteases:Pancreatic Proteases:

Trypsin converts proteins, proteases andTrypsin converts proteins, proteases andpeptones to polypeptides and peptidespeptones to polypeptides and peptides

Chrymotypsin converts proteases and peptonesChrymotypsin converts proteases and peptones

to polypeptides and dipeptides also coagulatesto polypeptides and dipeptides also coagulatesmilkmilk

Carboxypeptidase converts simpler peptides,Carboxypeptidase converts simpler peptides,

dipeptides and amino acidsdipeptides and amino acids

Amiinopeptidase converts polypeptides toAmiinopeptidase converts polypeptides topeptides and amino acidspeptides and amino acids

Dipeptidase converts dipeptides to amino acidsDipeptidase converts dipeptides to amino acids


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The Large intestineThe Large intestine

Absorbs water and some other nutrients,Absorbs water and some other nutrients,

and collects food residue for excretionand collects food residue for excretion


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ABS ORPTI ONBS ORPTI ONIs the passage of nutrients into the blood orIs the passage of nutrients into the blood or

lymphatic systemlymphatic system

Small IntestineSmall Intestine

Villi absorbs nutrients from the chyme, thenVilli absorbs nutrients from the chyme, then

transferred them to the bloodstreamtransferred them to the bloodstream Glucose, fructose, galactose,amino acids,Glucose, fructose, galactose,amino acids,

minerals and some water soluble vitamins areminerals and some water soluble vitamins areabsorb by the capillariesabsorb by the capillaries

Fructose and galactose are carried to the liver Fructose and galactose are carried to the liver converted to glucoseconverted to glucose

Lacteals absorbs glycerol and fatty acids inLacteals absorbs glycerol and fatty acids inaddition to fat soluble vitaminsaddition to fat soluble vitamins


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Large IntestineLarge Intestine

Absorbs waterAbsorbs water

Synthesize some B vitamins and vitamin KSynthesize some B vitamins and vitamin K

(essential for blood clotting)(essential for blood clotting) Collect food residue food that cannot beCollect food residue food that cannot be

digested and absorb (dietary fiber)digested and absorb (dietary fiber)


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MET ABOL IS MET ABOL IS M Nutrients are carried by the blood to theNutrients are carried by the blood to the

cells of the body, within the cell, nutrientscells of the body, within the cell, nutrients

are changed into energy through a processare changed into energy through a process

Governed by hormone secretionsGoverned by hormone secretions


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Thyroxine and Triiodothyronine Thyroxine and Triiodothyronine

stimulates metabolismstimulates metabolism

Calcitonin reduces blood calcium levelCalcitonin reduces blood calcium level

Anti-diuretic Hormone promotesAnti-diuretic Hormone promotes

retention of waterretention of water

Lipotropin release and oxidation of fatsLipotropin release and oxidation of fats

from adipose tissuefrom adipose tissue

Parathyroid hormone raises bloodParathyroid hormone raises bloodcalcium levelcalcium level

Aldosterone promote reabsorption of NaAldosterone promote reabsorption of Na

and K in kidneys,and K in kidneys,


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Insulin reduces blood glucoseInsulin reduces blood glucose

Glucagon raises blood glucoseGlucagon raises blood glucose

Gastrin stimulates glands to release HCLGastrin stimulates glands to release HCL

Secretin increase release of bileSecretin increase release of bile

Cholecystokenin stimulates release ofCholecystokenin stimulates release of

enzyme rich juice in the pancreasenzyme rich juice in the pancreas

The Digestive System-nutrition

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