SCIENCE

• Digestion - process in which food is broken down into smaller molecules
• Two Phases of Digestion

  • mechanical
  • chemical
• Five Key Processes of the Digestive System

  • ingestion
  • digestion (both mechanical and chemical)
  • absorption
  • transport
  • excretion
• Food is broken down into small pieces by the process of chewing or mastication
• Food is acted upon by chemical substances called enzymes
• Pharynx or Throat - located at the back of the mouth, common passageway for digestion and respiration
• Esophagus - muscular tube through which food passes from the pharynx to the stomach
• Peristalsis - process of transporting food through the esophagus
• Stomach - expanded organ located between the esophagus and small intestine
• Small intestine - considered as the organ of complete digestion and absorption
• large intestine or colon - next organ after small intestine
• Three parts of the Colon/large intestine

  • ascending colon
  • transverse colon
  • descending colon
• Rectum - located at the end of the sigmoid colon and serves as warehouse for feces
• Anus - functions as the exit point of fecal materials
• Gastroesophageal Reflux Disease (GERD) - condition when the acid in the stomach goes to the esophagus
• Gallstones - hard materials or deposits that are formed in the gallbladder
• Stomach Ulcer - condition occurs when the thick layer of mucus that protects the stomach from acid is reduced
• Irritable Bowel Syndrome (IBS) - digestive problem that affects the colon or large intestine
• Appendicitis - ailment that can cause pain in the lower right abdomen
• Mitosis - The division of the nucleus of the cell into two new nuclei
• Cytokinesis - actual division of the cell into new cells
• Chromatin - thin fibrous form of DNA and proteins
• Meiosis - division of the nucleus that reduces chromosome number by half, important in sexual reproduction
• Diploid - two sets of chromosomes, in humans 23 pairs or 46 total
• Haploid - one set of chromosomes 23 pairs of chromosomes
• Punnett Squares - used to determine the probability offspring will express a certain genotype