Test Your Knowledge of the Anatomy and Physiology of the Stomach

Study Notes

The stomach is made up of four layers: the mucosa, submucosa, muscularis externa, and serosa.
The mucosa contains various glands that secrete the components of gastric juice.
In the body of the stomach, there are parietal cells that secrete hydrochloric acid or HCl, a strong acid that helps to break down protein.
When pepsinogen is exposed to HCl it activates to becomes pepsin - an enzyme that helps break down proteins.
In the antrum, there are mucous cells which secrete mucus which protects the stomach lining from the acidic environment. There are also G cells which secrete a hormone called gastrin.
Gastrin increases the HCl secretion of the parietal cells, it increases pepsinogen secretion by the chief cells, and it also increases the contraction of the stomach muscles.
The next layer is the submucosa which mainly contains connective tissue, blood vessels, and nerves.
The nerves in the submucosa branch out and connect with one another forming the submucosal plexus of nerves which actually stretch throughout the gastrointestinal tract.
In the stomach, the submucosal plexus regulates gastric secretions of various glands and controls blood flow to the stomach.
The muscular layers of the stomach include an outer longitudinal layer, a middle circular layer, and inner oblique layer which is unique to the stomach.
The thickness of the muscular layers increases as you go from the orad region to the caudad region and that helps push food towards and past the pyloric sphincter.
The enteric nervous system is made up of both the myenteric and submucosal plexuses and it can function autonomously.
The gastrointestinal tract is made up of the stomach, small intestine, and large intestine.
The gastrointestinal tract is divided into the upper and lower gastrointestinal tracts.
The myenteric plexus is a group of nerves that connect the gastrointestinal tract to the central nervous system.
The outermost layer of the gastrointestinal tract is the serosa.
The stomach has waves of peristalsis that move food towards the pyloric sphincter.
The enteric nervous system regulates the rate that the stomach contracts.
Gastric emptying usually happens in a few hours, but it varies depending on the stomach contents.
Foods high in fat slow down gastric emptying.
Acidic substances containing lots of protons slow down gastric emptying because the high concentration of protons in the chyme sends information to gastric smooth muscle cells through interneurons in the myenteric plexus. This slows down the delivery of gastric contents to the duodenum, which is necessary for pancreatic enzymes to work in the duodenum.

Description

The quiz is about the function of the stomach. It is made up of four layers: the mucosa, submucosa, muscularis externa, and serosa. The mucosa contains various glands that secrete the components of gastric juice. In the body of the stomach, there are parietal cells that secrete hydrochloric acid or HCl, a strong acid that helps to break down protein. When pepsinogen is exposed to HCl it activates to become pepsin - an enzyme that helps break down proteins. In the antrum, there