Which part is the cardia?

Many people do not know where the cardia is in the human body, so whenever they hear about many diseases related to the cardia, they have no idea where the disease occurs, let alone what symptoms will appear. In fact, the cardia is the connecting part between the stomach and esophagus. People who have bad eating habits are prone to diseases in the cardia. If you don’t know the location of the cardia yet, let’s learn more about it below.

Which part is the cardia?

The anatomical cardia is located at the esophageal-gastric junction where the tubular esophagus extends downward into the sac-like stomach wall, at the level of the angle of His or the peritoneal reflection, equivalent to the lower edge of the lower esophageal sphincter, and is continuous with the esophagus upward. It is usually located on the left side of the 11th thoracic vertebra and behind the 7th costal cartilage, about 10 cm away from the anterior abdominal wall and about 40 cm away from the central incisor. The abdominal part of the esophagus turns sharply to the left as it descends, and becomes continuous with the cardia. The right edge of the esophagus is continuous with the lesser curvature of the stomach, and the left edge is continuous with the greater curvature of the stomach. There is no specific anatomical sphincter associated with the cardia.

The cardiac mucosa is composed of a single layer of columnar epithelium and mucous glands composed only of mucous cells. In the past, most people believed that the cardiac mucosa was a normal tissue that existed from birth. However, in recent years, more and more scholars have proposed that CM is not a natural structure, but is formed by metaplasia of the terminal esophagus and may be an early histological manifestation of esophagogastric junction reflux disease.

There are three main types of cells at the esophageal gastric junction: mucous cells, parietal cells, and chief cells. The mucus secreted by the mucous cells of the cardiac gland is neutral mucus, which is positive for PAS in mucus histochemical staining and negative for Alcian blue (AB, Alcia blue) (pH 2.5). The main method for identifying parietal cells is the fluorescent probe acridine orange (AO): the nucleus of parietal cells fluoresces yellow-green and the cytoplasm glows red, while the cytoplasm of other cells is not stained. The chief cells were double immunohistochemically stained with pepsinogen as a marker using pepsinogen antibody and PA-SP. To distinguish principal cells from parietal cells, add toluidine blue and poinsettia dyes and then distinguish them under a light microscope based on cell size, structure, and color: the principal cell nucleus appears dark blue after Hem staining, while the parietal cell diameter is longer than that of the principal cell and appears red after staining. It is difficult to distinguish between mucous cells and chief cells by HE staining and Malory's staining, but they can be distinguished by mucous carmine staining or PAS reaction staining.