Structure/Morphology
Unlike the muscular layer elsewhere in the digestive tract which consists of two fiber layers, the muscular layer of the stomach has three muscle fiber layers.
The innermost oblique muscle fibers of the stomach are unique to the stomach and found nowhere else in the digestive tract. These fibers are oriented somewhat in parallel with the longitudinal axis of the stomach.
The circular layer is the middle layer of the muscular layer of the stomach. Its fibers are oriented perpendicular to the long axis of the digestive tract. This layer is analogous to the circular layer of muscle found throughout the digestive tract.
The longitudinal muscular layer of the stomach is the outermost fiber layer of the muscular layer of the stomach. These fibers are oriented in parallel with the longitudinal axis of the stomach and are continuous with the longitudinal layer of the esophagus and duodenum.
Related parts of the anatomy
Key Features/Anatomical Relations
The myenteric plexus of nerves, also known as Auerbach’s plexus, sits between the circular layer and the outermost longitudinal layer of muscle fibers in the muscular layer (Standring, 2016).
Function
The muscular layer of the stomach grinds food and mix digestive gastric juices in the stomach. The longitudinal fibers shorten the stomach, the circular fibers create a peristaltic movement of contents, and the oblique fibers aid in the mixing of the stomach contents.
List of Clinical Correlates
- Gastroparesis
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41 edn.: Elsevier Limited.
