Chapter 3

gluten can increase in celiac disease in the United States

smallest units of life to largest : cell, tissue, organ, orgaan system

Carbohydrates → single sugar units (monosaccharides)

Proteins → amino acids

Fats → fatty acids and glycerol

Vitamins and minerals are released during digestion

4 basic stages of digestion

Ingestion Digestion Absorption Excretion

Digestive system organs in (GI tract)

mouth, esophagus, stomach, small intestine, large intestine

digestive system accesory organs

Salivary glands Liver Gallbladder Pancreas

Tasting

Primary tastes: Sweet Sour Salty Bitter Umami (meaty flavor)

Processes of digestion

Mechanical digestion

  • Physical breakdown of food
  • Begins in the mouth

Chemical digestion

  • Breaks chemical bonds to cleave large molecules into smaller ones
  • Involves enzymes and other substances
Muscle contractions

Peristalsis

  • Propulsive contractions move food forward from esophagus to anus

Segmentation

  • Uncoordinated contractions

              Mix intestinal content with digestive fluids

              Bring nutrients in contact with absorptive surface

fun facts stomach has the strongest muscle in GI tract

Food churned into fragments that disperse in gastric fluid

Gastric juices contain:

Hydrochloric acid

Enzymes

  • Proteases
  • Lipase

Mucus

  • Lubricates food
  • Protects stomach lining
Mechanical Digestion

Small Intestine Peristalsis Segmentation

Small intestine

Coiled hollow tube that is approximately 20 feet long

  • Duodenum
  • Jejunum
  • Ileum

Brush border

  • Villi
  • Microvilli
secretion from accesssory organs

Liver

  • Bile (stored in gallbladder)

        ---Digestion of fats

Small intestine

  • Hormone cholecystokinin

        ---Stimulates bile release

Pancreas

  • Pancreatic juices

---Bicarbonate

---Amylase

---Proteases

---Lipase

Circulatory system

Blood Carbohydrates, amino acids, minerals, water-soluble vitamins Lymphatic system Most fats and some vitamins

large intestine species of bacteria

Probiotics Help restore or maintain a healthy balance of “friendly” bacteria in the GI tract Prebiotics Nondigestible carbohydrates used by probiotics to boost growth

Digestive disorders

Acid reflux GERD Gallstones Vomiting Diarrhea Constipation Hemorrhoids Diverticular disease Gastritis Ulcer

Gluten causes inflammation in the small intestines in people with celiac disease