NCLEX : Gastrointestinal Physiology
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Example Questions
Example Question #31 : Gastrointestinal Physiology
Which of the following is the main signaling molecule that acts on salivary acinar cells to increase production of saliva?
Serotonin
Dopamine
Epinephrine
Acetylcholine
Acetylcholine
The primary signaling molecule that acts to increase saliva production by acinar cells in salivary glands is acetylcholine (ACh). ACh is released by parasympathetic innervation and triggers muscarinic receptors in salivary cells, leading to increased saliva secretion. While serotonin, epinephrine, and dopamine may have some effect on salivation, they are not the primary molecules through which the process is controlled.
Example Question #32 : General Biology
In what part of the brain is the swallowing center located?
The cerebellum
The thalamus
The cingulate gyrus
The medulla
The medulla
The swallowing center is not a specific anatomical structure, rather an area of physiological control. The swallowing reflex is primary controlled by the medulla, and to a lesser degree by the pons. None of the other structures listed play a significant role in deglutition.
Example Question #32 : Gastrointestinal Physiology
Which of the following molecules is necessary for absorption of vitamin B12?
Serotonin
Intrinsic factor
Sodium
Norepinephrine
Intrinsic factor
Dietary vitamin B12 must first form a complex with intrinsic factor, a gastric glycoprotein, before it can be absorbed into the hepatic portal system. Individuals who are unable to produce intrinsic factor are at risk for developing B12-related macrocytic anemia. While the other molecules listed are necessary for a wide variety of digestive and nervous system function, they do not directly control vitamin B12 absorption.
Example Question #331 : Nclex
Which of the following enzymes breaks down triglycerides in chylomicrons and very low-density lipoproteins (VLDL)?
Colipase
Lingual lipase
Hepatic lipase
Lipoprotein lipase
Lipoprotein lipase
Lipoprotein lipase hydrolyzes triglycerides into two free fatty acids and one molecule of monoacylglycerol.
Hepatic lipase aids in the regeneration of LDL. Colipase is secreted by the pancreas and is an important co-enzyme for optimal function of pancreatic lipase. Lingual lipase is a fat-digesting enzyme that is secreted in the saliva and aids in the break down of dietary lipids before they are stored in chylomicron form.
Example Question #34 : Gastrointestinal Physiology
All of the following large intestine bacteria are considered beneficial except __________.
Lactobacillus acidophilus
Lactobaccilus plantarum
Clostridium difficile
Streptococcus thermophilus
Clostridium difficile
All of the bacterial strains listed have been shown to have beneficial effects on gut and immune health except for Clostridium difficile, a pathogenic bacteria commonly seen in hospital settings after prolonged antibiotic use. C. difficile has been associated with chronic diarrhea, behavioral disorders, and colitis.
Example Question #35 : Gastrointestinal Physiology
Where is intrinsic factor produced?
In the stomach by chief cells
In the stomach by parietal cells
In the Brunner's glands of the duodenum
In the pancreas by beta islet cells
In the stomach by parietal cells
Intrinsic factor, a molecule necessary for the absorption of dietary B12, is produced by the parietal cells of the stomach. Its release stimulated by the same factors that stimulate release of hydrochloric acid: histamine, gastrin, and acetylcholine.
Gastric chief cells secrete pepsinogen and chymosin, while beta islet cells of the pancreas secrete insulin. Brunner's glands secrete a mucus that protects th lining of the intestine.
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