What is the Difference Between Parietal and Chief Cells

The main difference between parietal and chief cells is that parietal cells secrete hydrochloric acid, whereas chief cells secrete pepsinogen.  

Parietal and chief cells are two cell types located in the gastric glands. The other cell types in the gastric glands are mucous neck cells and enteroendocrine cells. They secrete different substances into the stomach.    

Key Areas Covered

1. What are Parietal Cells
– Definition, Structure, Function
2. What are Chief Cells
– Definition, Structure, Function
3. Similarities Between Parietal and Chief Cells
– Outline of Common Features
4. Difference Between Parietal and Chief Cells
– Comparison of Key Differences

Key Terms 

Chief Cells, Delomorphous Cells, Oxyntic Cells, Parietal Cells, Peptic Cells, Zymogenic Cells

What are Parietal Cells

Parietal cells (or oxyntic cells or delomorphous cells) are a type of cells in the gastric gland. They occur in the middle region of the gastric gland. They are a type of epithelial cells that are highly differentiated. The primary function of the parietal cells is to secrete hydrochloric acid and intrinsic factors into the stomach. Hydrochloric acid is responsible for the high acidic pH inside the stomach. The pH of the stomach is 1.5 to 3.5. the acidity inside the stomach is important for killing pathogens and denaturing proteins. It makes the protein available for enzymatic digestion. Apart from that, hydrochloric acid is important for activating pepsinogen enzyme into pepsin. Importantly, the intrinsic factor is a glycoprotein required by the absorption of vitamin B12 by the small intestine. 

Figure 1: Parietal Cells

Furthermore, acid secretion is important for the digestion of food and the absorption of ions. However, regulation of acid secretion is also important. Therefore, the vagus nerve, histamine, gastrin, ghrelin, glucagon-like peptide 1, and somatostatin regulate acid secretion in the stomach. 

What are Chief Cells

Chief cells (or Peptic Cells or Zymogenic Cells) are another cell type that occurs in the gastric glands. They occur at the base of the gastric gland. Their function is to secrete pepsinogen and chymosin. The contact of pepsinogen with the hydrochloric acid activates pepsinogen and converts it into pepsin. However, chymosin or renin is responsible for coagulation of milk. Also, chief cells in the stomach secrete lipase enzyme that digests triglycerides. They form free fatty acids and monoglycerides. In addition, chief cells produce leptin in response to food in the stomach.

Figure 2: Chief Cells

Moreover, the chief cells in the gastric gland are cells with longer lifespans. Also, they form the base of the gastric gland. They contain an extensive lamellar rough endoplasmic reticulum network that organizes around the nucleus. In addition to that, many large secretory vesicles occur inside the chief cells. 

Similarities Between Parietal and Chief Cells 

• Parietal and chief cells are two cell types of gastric glands.
• They secrete different substances into the stomach.
• They are highly differentiated epithelial cells. 

Difference Between Parietal and Chief Cells

Definition

Parietal cells refer to epithelial cells in the stomach that secrete hydrochloric acid (HCl) and intrinsic factor. In contrast, chief cells refer to cells in the stomach that synthesize and release the proenzyme pepsinogen.

Other Names

The other names for the parietal cells include oxyntic cells and delomorphous cells, while other names for the chief cells include peptic cells and zymogenic cells. 

Location

Parietal cells are located in the middle region of the gastric gland, while chief cells are located in the basal region of the gastric gland.  

Function

Parietal cells secrete hydrochloric acid and intrinsic factor, while chief cells secrete pepsinogen. 

Conclusion

In brief, parietal and chief cells are two cell types that occur in the gastric gland. The mucous neck and enteroendocrine cells are the other cells in the gastric gland. Parietal cells occur in the middle region of the gastric gland. Also, they secrete hydrochloric acid and intrinsic factors. In comparison, chief cells occur in the basal region of the gastric gland. However, they secrete pepsinogen into the stomach. Therefore, the main difference between parietal and chief cells is their location and function.

References:

1. Libretexts. (2022b, May 13). 23.4: The stomach. Medicine LibreTexts. 

Image Courtesy:

1. “Chief cells” By en:User:Jpogi – Own work (CC-BY SA 3.0) via Commons Wikimedia
2. “Stomach with prominent parietal cells — high mag” By Nephron – Own Work (CC-BY SA 3.0) via Commons Wikimedia