BIOD 151 Module 3 EXAM ANSWER KEY
Explain why someone who has hypergastrinemia (excessive secretion of gastrin) might develop gastric/stomach
... [Show More] ulcers.
Gastrin stimulates the secretions of pepsinogens and hydrochloric acid. Excess
amounts would lead to erosion of the stomach lining.
Explain in detail how the stomach contents enter the small intestine
The pyloric sphincter (valve), located at the base of the stomach, relaxes causing
a small quantity of chyme to pass through the opening into the first part of the
small intestine.
This initiates a reflex that causes the muscles of the sphincter to contract and
close the opening temporarily. Then the sphincter relaxes again and allows more
chyme to enter.
Be able to label the following:
Stomach
Gallbladder
Jejunum (not small intestine)
Appendix (not large intestine)
Rectum (not large intestine
...
A patient is experiencing vitamin toxicity. What type of vitamin would be causing this
toxicity? Explain your answer.
A. Water soluble vitamin
B. Fat soluble vitamin
C. All of the above
Fat soluble vitamins are stored within the body's fat stores making it harder for
the body to rid itself of them.
Explain which digestive system functions are carried out by the large intestine.
Absorption: In the large intestine water and electrolytes are reabsorbed and
vitamins are absorbed.
Defecation: Feces travel to the rectum where it is excreted via the anus.
Describe parietal cells and chief cells: name their location, secretions and purposes.
The parietal cells (located in the wall of the stomach body) secrete hydrochloric
acid, generating a pH of 1.3-3.5. This very acidic pH kills many of the bacteria
ingested along with food. In addition, the low pH stops the activity of salivary
amylase. The secretion of hydrochloric acid is essential in the activation of
pepsin.
Chief cells: secrete pepsinogen. Pepsinogen (a pre-enzyme) is secreted by the
chief cells in the stomach. Hydrochloric acid converts the inactive pepsinogen
(secreted by the chief cells) into the active enzyme pepsin which begins the
breakdown of proteins [Show Less]