Brent Cornell

     
Understandings:

• Nervous and hormonal mechanisms control the secretion of digestive juices
• Exocrine glands secrete to the surface of the body or the lumen of the gut
• The volume and content of gastric secretions are controlled by nervous and hormonal mechanisms
• Acid conditions in the stomach favour some hydrolysis reactions and help to control pathogens in ingested food
• The structure of cells of the epithelium of the villi is adapted to the absorption of food
• The rate of transit of materials through the large intestine is positively correlated with their fibre content
• Materials not absorbed are egested

Applications:

• The reduction of stomach acid secretion by proton pump inhibitor drugs
• Dehydration due to cholera toxin
• Helicobacter pylori infection as a cause of stomach ulcers

Skills:

• Identification of exocrine gland cells that secrete digestive juices and villus epithelium cells that absorb digested foods from electron micrographs