The gastric folds (or gastric
rugae) are coiled sections of tissue that exist in the
mucosal and
submucosal layers of the
stomach.[1] They provide
elasticity by allowing the stomach to expand when a
bolus enters it. These folds stretch outward through the action of
mechanoreceptors, which respond to the increase in
pressure.[2] This allows the stomach to expand, therefore increasing the
volume of the stomach without increasing pressure.[2] They also provide the stomach with an increased
surface area for nutrient absorption during
digestion.[2] Gastric folds may be seen during
esophagogastroduodenoscopy or in
radiological studies.[3][4]
Layers
The gastric folds consist of two layers:
Mucosal layer – This layer releases
stomach acid. It is the innermost layer of the stomach.[5] It is affected by the hormone
histamine, which signals it to release
hydrochloric acid (HCl).
Sub-mucosal layer – This layer consists of different vessels and
nerves, ganglion neurons, and
adipose tissue. It is the second layer of the stomach and supports the mucosa.[6]