digestion for moodle
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Digestive System
Mrs. Stein
Nutrients Supply the body with materials for energy, growth,
and maintenance Carbohydrates - major energy source
Simple (fruit, sugar) and complex (starch, grain) Fats (lipids) - found in cell membranes
Fatty acids and glycerol Proteins play a variety of roles; growth, repair
Amino acids Meat, beans, dairy
Vitamins help regulate processes Minerals are inorganic compounds needed in small
amounts Calcium in bones, iron in hemoglobin
Digestive System
Pharynx
SalivaryGlands
Stomach
Esophagus
Mouth
Large Intestine
Gallbladder (behind the liver)
LiverPancreas
(behind stomach)
Rectum
Small Intestine
Digestion Break down large
molecules into smaller molecules which can be used by cells
Physical and chemical Alimentary Canal – one
way tube which food passes through the body
Accessory structures do not carry food, but aid in digestion
PharynxSalivaryGlands
Stomach
Esophagus
Mouth
Large Intestine
Gallbladder (behind the liver)
LiverPancreas
(behind stomach)
RectumSmall
Intestine
Accessory Structures Liver produces bile which emulsifies fat Gallbladder stores bile Pancreas produces enzymes
Mouth Mechanical digestion
Teeth crush food Saliva moistens food and
contains salivary amylase Starch into simpler sugar Chemical digestion
Esophagus Muscular tube connects
pharynx & stomach Peristalsis
Waves of muscle contractions Bolus enters the stomach
thru a sphincter Acid may back up into the
esophagus Heartburn, reflux
Stomach
Chemical digestion HCl kills bacteria, lowers pH to activate pepsin Proteins break down
Peptic ulcer – hole in stomach wall Caused by bacteria
Muscular sac lined with mucus Protection, lubrication
Mechanical digestion Smooth muscles churn
food
Small Intestine Duodenum - 1st part of the small intestine
Enzymes & fluids enter here Carbohydrates, lipids, and proteins
digested here Nutrients absorbed
PharynxSalivaryGlands
Stomach
Esophagus
Mouth
Large IntestineGallbladder
(behind the liver)
Liver Pancreas (behind stomach)
Rectum
Small Intestine
Small Intestine Lined with finger-like projections called villi
Increase surface area for absorption Carbs and proteins
enter capillaries Fats enter the
lymph vessels Water, cellulose,
and indigestibles remain
Large Intestine Absorbs water from
undigested material Bacteria synthesize
vitamin K Feces is stored in the
rectum, excreted by the anus
Enzymes Stomach
Pepsin – proteins smaller peptide chains Rennin – curdles milk proteins
Pancreas produces 3 enzymes which are secreted into the duodenum Pancreatic amylase – starch maltose Trypsin – proteins amino acids Lipase – fats fatty acids and glycerol
Enzymes of the Small Intestine Enzymes break disaccharides into
monosaccharides Maltase: maltose 2 glucose molecules Lactase: lactose glucose and galactose Sucrase: sucrose glucose and fructose
Peptidase – breaks down small polypeptides into amino acids
Enzyme or Digestive
Fluid
Where it is manufactur
edWhere it
actsWhat
molecule it acts on
What results from
its actionSalivary Amylase
Mouth Maltose
Gastric Glands Stomach Proteins
Bile Duodenum
Pancreas Duodenum Starch
Trypsin Duodenum
Pancreas Duodenum Lipids
Maltase Duodenum Maltose
Duodenum Duodenum Glucose and Fructose
Lactase Duodenum Duodenum
Duodenum Duodenum Amino Acid
Pepsin
Salivary Gland
Liver
Polypeptides
Starch
Smaller Lipids
Pancreatic Amylase
Lipids
Pancreas Smaller PeptidesPolypeptides
Maltose
Lipase
Sucrase
Duodenum
Fatty Acids & Glycerol
Sucrose
Glucose
Glucose & GalactoseLactose
PeptidesPeptidase
Accessory Structures
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