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I Digestionoverview

• Bless you!

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3 parts of Digestion

• 1. Digestion breakdown of organic cules into
  smaller nutrients physical and chemical process

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• 2. Absorption movement of digested nutrients
  from intestine into body

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• 3. Elimination exit of undigested waste

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PATHWAY

• Mouth -gtPharynx-gtEsophagus-gtStomach-gt Small
  Intestine-gtLarge Intestine-gt Rectum-gtAnus
• 3 Accessory Organs
• Assist in digestive process
• Liver, Gall Bladder
• Pancreas

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Mouth

• 1. Physical digestion of food
• -Teeth -Increases surface area of
• food
• 2. Chemical digestion of food
• Saliva - salivary glands
• -contains
• a) Water lubricant
• b) SALIVARY AMYLASE
• an enzyme - hydrolyses STARCH to MALTOSE

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Pharynx (throat) swallow

• Food now is BOLUS
• Dual passageway for food air
• Divides into trachea (resp.) esophagus

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Esophaguslong muscular tube

• Bolus moves down by muscle contractions,
  peristalsis view it!
• Lined with mucus
• Connects to stomach via cardiac sphincter

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Stomacha thick-walled, J-shaped organ

• 3 functions of
• 1)Muscular walls churn mix food
• 2) Stores food releases slowly to s. intestine
• 3) makes gastric juice- secreted by gastric glands

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Stomach Gastric Juice

• Gastric Juice Contains
• 1. Water - SOLVENT
• 2. HCl extremely acidic pH 2-3
• Acidity destroys pathogens changes pepsinogen
  into active form PEPSIN
• 3. Pepsinogen------? PEPSIN
• PEPSIN an enzyme that hydrolyses proteins into
  smaller chains of amino acids called - PEPTIDES

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Stomach contd

• Protein water peptides
• Stomach lining protected by a lining of mucus
  ulcers
• After 2-6 hrs. bolus is converted to
• ACID CHYME (think VOMIT!)

PEPSIN
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Holy Cow What is it??
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(No Transcript)
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Small Intestine3-7 metres long 2- 5 cm

• 2 functions
• Complete the rest of chemical digestion
• Absorb nutrients into BLOOD and LYMPH

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Contd -Small Intestine

• Connects to stomach above via
• PYLORIC SPHINCTER to L. intestine below VIA
  Illeocaecal valve (sphincter)
• Has 3 areas duodenum
• -jejunum
• -ileum

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Chemical Digestion in S. Intestine

• S. intestine connected to 2 accessory organs
• 1) Pancreas
• 2) Gallbladder

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Pancreasmakes and sends pancreatic juice to S.I.

• Pancreatic Juice made in pancreas
• Contains
• 1. Sodium Bicarbonate neutralizes acid chyme
  changes pH to 8.5(alkaline-basic)
• 2. Lipase enzyme for LIPIDS
• 3. Trypsin enzyme for peptides (2 for
  proteins)
• 4. Pancreatic Amylase enzyme for starch
• 5. Nucleases enzyme for nucleic acids
• 6. Water

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2) Gallbladderconnected to LIVER SI

• Function store send BILE to SI via bile duct
• BILE is NOT an enzyme
• Helps in physical digestion of LIPIDS
• Breaks LIPIDS into smaller particles this is
  called EMULSIFICATION
• Bile is made by liver

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Enzymes Made in SI Cells lining SI make
secrete enzymes that will finish chemical
digestion

• 1.Maltase breaks maltose into glucose
• 2.Peptidase breaks peptides into a.a.s
• Chemical Digestion Now complete!!!!

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2nd Function of SIAbsorption

• Accomplished through structures called VILLI
  finger like projections covering lining of SI
• This increases SA increases absorption
• of nutrients
• Villi many Villus - one

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Large Intestinereceives undigested wastes
fibers (cellulose)

• 2 main functions
• Absorb water released in SALIVA, GASTRIC JUICE,
  PANCREATIC JUICE, INTESTINAL SECRETIONS
• Synthesis of vitamins

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2 main parts of LI

• Colon
• Upper portion of LI
• Contains E. Coli, synthesize vitamins (K) that we
  absorb
• Water moves by OSMOSIS to body

• Rectum
• Storage of feces
• 1/3 dead bacteria

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Funniness..

• Watch it!

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Liver 6 functions KNOW!!!B.B.B.B.B.U.

1. Blood Sugar -regulates
2. Blood detoxify
3. Bile produce
4. Blood proteins produce
5. Blood Cells red break down
6. Urea - produce

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Pancreas 2 functions1) exocrine gland
digestive secretions (list 6)2) endocrine gland
produce hormones insulin glucagon

• Role of Insulin Glucagon

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Digestion Overview
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• Reminders Digestion/Circulation Test
• Next Tuseday change!!!!
• Villus Assignment Due Next Thurs.
• Friday - Digestion ALL quizziness!!