Final answer:
The esophagus angles slightly to the left to connect to the stomach at the cardia, after passing through the diaphragm at the esophageal hiatus. This connection is regulated by the lower esophageal sphincter, which controls the passage of food to the stomach and prevents acid reflux.
Step-by-step explanation:
After the esophagus passes through the diaphragm muscle via the esophageal hiatus, it angles slightly as it enters the stomach. Specifically, the esophagus connects to the stomach at an area known as the cardia, which is slightly left of the midline. The final section of the esophagus includes a special muscle called the lower esophageal sphincter, which acts as a valve to control the passage of contents between the esophagus and the stomach. This sphincter relaxes to allow the bolus of food to enter the stomach and then contracts to prevent the acidic contents of the stomach from entering back into the esophagus, thus protecting the esophagus from acid reflux. When not swallowing, this sphincter remains closed, maintaining a pressure barrier between the esophagus and the stomach.