practice questions

• one organ of the alimentary canal found in the thorax

  esophagus
• three organs of the alimentary canal found in the abdominal cavity

  stomach, small intestine, large intestine
• which digestive system activity actually moves nutrients from outside of the body to inside the body?

  absorption moves nutrients
• Visceral peritoneum is located on the outside of the organ and the parietal peritoneum lines the organ on the inside.
• Out of the stomach, pancreas, and liver which ones are retroperitoneal?

  pancreas
• what are the layer of the alimentary canal from inside to the outside?

  mucosa to submucosa to muscularis externa to serosa
• What is the venous portion of the splenic circulation?

  hepatic portal circulation
• Smooth muscle is perfect for the stomach because it contractions as one units due to their gap junctions.
• Secretion of hormones and motility of organs are put in action by reflexes of the "gut brain"
• The gut brain refers to the clump of enteric neurons that communicate together to control the digestive tract
• Parasympathetic system puts the digestive tract into action and the sympathetic inhibits the system.
• The plate forms the top of the mouth. You have the hard that helps mechanically breakdown food and the soft that closes the nasopharynx
• The tongue pushes the bolus down into the esophagus
• What are the antimicrobial substances in saliva?

  lysozyme, definsins, and IgA antibodies
• The enamel of the tooth is harder than bone and the pulp holds all the nervous tissue and blood vessels.
• The pharynx belongs to digestive and respiratory systems
• The muscularis externa of the esophagus starts with skeletal muscle and moves to smooth muscle.
• Why does the epithelium change at the esophagus-stomach junction?

  Esophagus is just a transport channel so the stratified squamous epithelium can withstand the the friction

  The stomach mucosa is a secretory mucosa that secretes mucus so simple columnar epithelium is right for that
• The tongue makes the food into a bolus with the saliva and chewing so it initiates ingestion
• During swallowing the larynx rises and the epiglottis covers the lumen so that food doesn't go down the wrong pipe
• Stomach has an additional layer of smooth muscle that allows for peristalsis
• pepsinogen, produced by chief cells, and HCl, produced by the parietal cells, are needed to produce protein-digesting enzyme pepsin
• What are the three phases of gastric secretion?

  Cephalic, gastric, intestinal
• The presence of food in the duodenum inhibits gastric activity by starting the enterogastric reflex and secretion of enterogastrone
• Enterohepatic circulation is important for recycling bile salts needed for fat absorption
• The mucosa is the nearest to the lumen of the small intestine
• muscularis externa is involved in peristaltic action in the small intestine
• parietal peritoneum lines the abdominal and pelvic cavities
• Mesocolon anchors the large intestine to the rear abdominal wall
• Pancreatic acini produce exocrine products of the pancreas so things like digestive enzymes and bicarbonate-rich juice
• pancreatic islets produce pancreatic hormones and most importantly insulin and glucose
• pancreatic duct produces bicarbonate-rich, enzyme-rich pancreatic juice
• Cystic and bile ducts transport bile
• CCK is secreted when it senses an entry into the duodenum of chyme rich in protein and fat

  • it causes the gallbladder to contract
  • pancreatic acini secretes digestive enzymes
  • relaxes hepatopancreatic
• microvilli, vili, circular folds all increase the surface area of the digestive area
• Brush Border Enzymes are enzymes on the vili that complete digestion for carbohydrates and proteins in the small intestine.