Digestive

• What are the two groups of organs in the digestive system?

  GI tract and accessory organs
• What is the GI tract also known as?

  Alimentary canal
• What organs are included in the GI tract?

  Mouth, pharynx, oesophagus, stomach
• What are the accessory digestive organs?

  Teeth, tongue, salivary glands, liver
• How can the GI tract be divided?

  Into upper and lower GI tract
• What is the border between the upper and lower GI tract?

  Suspensory ligament of the duodenum
• What are the six basic processes of the GI tract?

  • Ingestion
  • Secretion
  • Mixing and propulsion (motility)
  • Digestion (mechanical/chemical)
  • Absorption
  • Defecation (excretion)
• What is the role of salivary glands in digestion?

  Lubricate bolus and provide enzymes
• What does amylase do?

  Breaks down starch into sugar
• What is an enzyme?

  A biological catalyst for chemical reactions
• What type of swallowing occurs in the esophagus?

  Both voluntary and involuntary
• How long is the esophagus?

  Approximately 25 cm long
• What are the two sphincters at each end of the esophagus?

  Upper and lower esophageal sphincters
• What type of epithelium is found in the esophagus?

  Stratified squamous epithelium
• What are the four layers of the GI tract?

  1. Mucosal layer
  2. Submucosal layer
  3. Muscularis layer
  4. Serosa
• What is the function of the stomach?

  Digestion of starch, proteins, and triglycerides
• What cells produce pepsin in the stomach?

  Chief cells
• What do parietal cells secrete?

  Hydrochloric acid (HCl)
• What activates pepsin in the stomach?

  Hydrochloric acid (HCl)
• What are the functions of the stomach?

  • Produce gastric juice (mucus, HCl, gastric lipase, pepsinogen)
  • Serve as a reservoir for food
  • Mix saliva, food, and gastric juice to form chyme
  • Secrete gastrin to stimulate gastric juice secretion
• What is the role of the pancreas in digestion?

  Secretes pancreatic juice for digestion
• What percentage of pancreatic clusters are acini?

  99%
• What does pancreatic juice consist of?

  Water, salts, sodium bicarbonate, and enzymes
• What is the function of sodium bicarbonate in pancreatic juice?

  Buffers acidic contents of the stomach
• What enzymes are included in pancreatic juice?

  Pancreatic amylase, trypsin, chymotrypsin
• What is the liver's role in digestion?

  Synthesizes bile salts and secretes bile
• How much bile does the liver produce daily?

  800-1000 ml
• Where is bile stored?

  In the gallbladder
• What is the function of bile?

  Emulsifies large lipid molecules
• What is bilirubin?

  A product of hemolysis excreted in bile
• What is the role of the liver in carbohydrate metabolism?

  Maintains plasma glucose levels
• What are the functions of the liver?

  • Carbohydrate metabolism
  • Breakdown of erythrocytes
  • Detoxification
  • Hormone inactivation
  • Production of heat
  • Storage (glycogen, iron, copper, vitamins)
  • Fat metabolism
  • Protein metabolism (deamination, transamination)
  • Synthesis of plasma proteins
• What are the three regions of the small intestine?

  1. Duodenum
  2. Jejunum
  3. Ileum
• How long is the duodenum?

  10 inches long
• What connects the duodenum to the jejunum?

  The pyloric sphincter
• What is the pH change in the duodenum?

  From 2 to 5
• How long is the jejunum?

  2.5 meters long
• What is the role of villi in the jejunum?

  Increase surface area for absorption
• What do lacteals collect in the small intestine?

  Fats and fluids
• How long is the ileum?

  2-4 meters long