Q1. Correct answer: E
Rationale
Transient lower esophageal sphincter relaxation (TLESR) is a physiologic phenomenon that allows venting of swallowed air from the stomach in response to distension of the proximal stomach. Patients with GERD typically reflux gastric content through a compliant esophagogastric junction into the esophagus during a TLESR; the frequency of TLESRs may also be higher in patients with GERD. TLESRs are suppressed during deep sleep, and are less frequent when LES relaxation is abnormal (e.g., esophageal outflow obstruction). Baclofen, a GABAB receptor agonist, can reduce TLESR frequency, and can reduce reflux episodes in patients with reflux. Obese patients and those with obstructive sleep apnea can have increased frequency of TLESRs. The frequency of TLESR is not related to degree of gastric acid secretion in the stomach.
References
Kuribayashi S et al. Neurogastroenterol Motil. 2010 Jun;22(6):611-e172.
Hershcovici T et al. Neurogastroenterol Motil. 2011 Sep;23(9):819-30.
