DIGESTIVE SYSTEM PP 979-991

FUNCTION Breakdown of food into simpler molecules which are then absorbed One long tube from mouth to anus

NUTRIENTS carbohydrates, fats, proteins minerals: help balance osmosis and the function of certain cells (i.e muscle cell) vitamins: aid enzyme activity water: accounts for half of your body weight

DIGESTIVE TRACT MOUTH AND ESOPHAGUS Amylase (enzyme) is released from glands into saliva Breaks down carbs to monosaccharides Bolus (food ball) travels down esophagus to stomach

STOMACH Muscle contractions break bolus a part Pepsin (enzyme) breaks down proteins into amino acids HCl keeps stomach acidic so the pepsin can work

LIVER Produces bile that breaks makes the fat molecules smaller

GALL BLADDER Stores bile and secretes it into the small intestine

PANCREAS Secretes sodium bicarbonate (base) into small intestine to neutralize acid

SMALL INTESTINE Trypsin (enzyme) breaks down proteins High surface area (villi and microvilli) for nutrient absorption Surrounded by blood vessels

LARGE INTESTINE/COLON Absorption of water, minerals, and vitamins

Figure 41.19 Hormonal control of digestion.   2 3 Food Bile Liver Stomach Secretin and CCK Chyme  Gastric juices Gastrin  Gastric juices Gallbladder CCK  Pancreas HCO3, enzymes Duodenum of small intestine Secretin  CCK  Key Figure 41.19 Hormonal control of digestion.  Stimulation Inhibition 

Satiety center     Ghrelin Insulin Leptin PYY Figure 41.21 Figure 41.21 A few of the appetite-regulating hormones. Leptin  PYY 

Salivary glands Esophagus Liver Stomach Pancreas Gall bladder Large intestine/colon Small intestine