Osmosis knows that anatomy can be overwhelming, but hopefully this video on the esophagus and stomach can make it a bit easier, so let's begin “digesting” this content together! The esophagus and the stomach are part of the upper digestive tract and are involved in the first phases of digestion. We are going to use the pizza we ate for dinner last night as an example to help us explore the pathway of the esophagus and stomach.
Now, let’s start with the esophagus, which is a muscular tube that carries food from the pharynx to the stomach. We can think about the esophagus as a subway that our food travels in between these two structures. After the pizza we ate has been chewed and swallowed, the muscles of the esophagus help propel the bolus towards the stomach in a wave-like motion called peristalsis.
The esophagus is made up of two muscular layers: an internal circular layer and an external longitudinal layer. In its proximal or superior third, the external layer consists of striated skeletal muscle, which is under voluntary control, while its distal or inferior third is made up of smooth muscle, which is under involuntary control.
And as you’d expect, the middle third is a transitional segment that consists of a mix of both types of muscle. The esophagus follows the curve of the vertebral column as it descends through the neck and into the mediastinum.
Once it reaches the diaphragm, it passes through the esophageal hiatus, just to the left of the median plane at the level of the T10 vertebra, where it becomes the abdominal esophagus. The abdominal esophagus finishes its journey by becoming continuous with the stomach through the cardial orifice, which is surrounded by the cardiac sphincter.