the digestive system

• the digestive system breaks down food into energy cells can use, after digestion is complete, nutrients are absorbed and transported to all cells.
• undigested materials are eliminated as liquid and solid wastes
• where digestion occurs for:

  • carbohydrates--> mouth
  • proteins--> stomach
  • fats/sugars--> small intestine
  • no digestion--> large intestine/site of stool formation
• chyme is semiliquid food moving from the stomach to the small intestine
• mechanical digestions:

  • mouth --> chewing shreds and grinding food into smaller particles
  • stomach --> Peristalsis churns food and breaks it down to mix it with digestive juices
  • small intestine --> muscular contractions break down and mix food with digestive enzymes, bile, and hormones
• smooth muscle contractions are called peristalsis
• chemical digestions:

  • mouth --> salivary amylase breaks down starches into simple sugars
  • stomach --> HCL and PEPSIN break down proteins into amino acids
  • small intestine --> enzymes, bile, and hormones finish the digestion of proteins, sugars, and fats.
• salivary amylase in the mouth break down starches into simpler sugars
• pepsin in the stomach breaks down proteins
• in the small intestine:

  • maltase/lactase/sucrase --> break down sugars into simpler molecules
  • peptidase --> break down proteins into amino acids
• in the small intestine, pancreas:

  • trypsin--> continues breakdown of proteins
  • amylase--> continues breakdown of starches
  • lipase--> aids in breaking down fats
• most digestion takes place in the duodenum
• the pancreas, liver, and gallbladder aid in digestion
• pancreas help digest fat and proteins
• bile produced by the liver and stored in the gallbladder helps the small intestine to digest fats and neutralize acid coming from the stomach