Biology

• Digestion


  The process by which foods are broken down for the body to use in growth, development, healing and prevention of disease
• Absorption


  The process by which digested proteins, fats, carbohydrates, minerals and water are actively and passively transported through the intestinal mucosa into the blood or lymphatic circulation
• Metabolism


  The complex chemical process that occurs in the cells to allow for energy use and for cellular growth and repair
• Nutritional Utilization


  • Digestion
  • Absorption
  • Metabolism
  • Excretion
  • Role of the Liver
• Peristalsis

  The waves of involuntary muscle contractions that transport food and waste matter
• Bile

  Food in small pieces and well mixed with saliva
• Food Bolus


  A thick fluid mass of partially digested food and gastric secretions passed from the stomach to the small intestine
• Chyme

  A semiliquid mixture of food
• Digestion in the Mouth

  1. Mechanical digestion through mastication (Chewing)

  2. Chemical digestion through the action of amylase (ptyalin) which breaks down starches into maltose

  3. Deglutition (swallowing) once the food is broken down into small pieces and well mixed with saliva (food bolus)
• Esophagus


  • Serves as passage for food bolus from mouth to stomach by peristalsis
  • Distal end is guarded by lower esophageal sphincter (LES) which prevents gastric reflux
• Stomach

  • Located in the left upper quadrant of the abdomen
  • Has a capacity of approximately 1500 ml
  • Has regions: cardiac, fundus, body & antrum or pyloric
  • Has a lesser or greater curvature