What is the Difference Between Reticulocyte and Erythrocyte

The main difference between reticulocyte and erythrocyte is that reticulocyte occurs in the early stages of blood cell formation whereas erythrocyte is the final product of erythropoiesis.

Generally, reticulocyte and erythrocyte are two developmental stages of red blood cells. Erythropoiesis is the process of formation and development of red blood cells or erythrocytes.    

Key Areas Covered

1. What is Reticulocyte
– Definition, Structure, Function
2. What is Erythrocyte
– Definition, Structure, Function
3. Similarities Between Reticulocyte and Erythrocyte
– Outline of Common Features
4. Difference Between Reticulocyte and Erythrocyte
– Comparison of Key Differences

Key Terms

Erythrocyte, Reticulocyte

What is Reticulocyte

A reticulocyte is a red blood cell that is still developing. Therefore, reticulocytes are known as immature red blood cells or erythrocytes. The production of reticulocytes occurs in the bone marrow. After production, they are sent to the bloodstream. Generally, reticulocytes take around two days to mature into erythrocytes in the bloodstream. Therefore, the main function of reticulocytes is to undergo maturation into erythrocytes in the bloodstream.

Figure 1: Reticulocytes

Furthermore, reticulocyte count is the number of reticulocytes in the bloodstream. However, too or low reticulocyte counts reflect serious health problems including anemia, and disorders of the bone marrow, liver, and kidneys.  Reticulocyte count is also important to diagnose anemia, check whether anemia treatments are working, check the production of reticulocytes in the bone marrow, and check the bone marrow function.  

What is Erythrocyte

Erythrocyte is a mature red blood cell, typically a biconcave disk shape cell without a nucleus. Erythropoiesis is the process of formation of erythrocytes. Millions of erythrocytes circulate in the vertebrate blood circulation. Erythrocytes contain hemoglobin, and their main function is to transport oxygen throughout the body.

Figure 2: Erythrocytes

Moreover, erythrocyte is the most common type of blood cell in the blood. The cytoplasm of the erythrocyte contains hemoglobin, an iron-containing biomolecule responsible for the transport of oxygen. In addition, hemoglobin is responsible for the red color of the erythrocytes. Mature erythrocytes lack nuclei and organelles to accommodate the space of the cell for hemoglobin. The erythrocyte count varies between 5 and 8 million/mm3 and the lifespan of erythrocytes is 60 to 70 days.   

Similarities Between Reticulocyte and Erythrocyte

• Reticulocytes and erythrocytes are two types of red blood cells in different developmental stages.
• Both do not have a cell nucleus.
• Moreover, they contain hemoglobin.
• Both occur in the bloodstream.
• Furthermore, their function is to transport oxygen to tissues of the body.

Difference Between Reticulocyte and Erythrocyte

Definition

Reticulocyte refers to an immature red blood cell without a nucleus, having a granular or reticulated appearance when suitably stained, while erythrocyte refers to a red blood cell, which (in humans) is typically a biconcave disc without a nucleus.

Shape

A reticulocyte is an irregular shape, multilobular cell while an erythrocyte is a biconcave disk shape cell.

Maturity

A reticulocyte is an immature erythrocyte while an erythrocyte is a mature cell.

Function

The main function of reticulocytes is to undergo maturation to become erythrocytes while the main function of erythrocytes is to transport oxygen through the bloodstream.

Conclusion

In brief, reticulocytes and erythrocytes are two developmental stages in the process of red blood cell formation called erythropoiesis. Both types of cells lack nuclei and contain hemoglobin. They occur in the bloodstream. A reticulocyte is an immature red blood cell and it has an irregular shape. It is also a multilobular cell. It undergoes maturation in the bloodstream within two days. Erythrocytes, on the other hand, are mature red blood cells with a biconcave shape. In addition, the main function of erythrocytes is to transport oxygen to the tissues of the body. Therefore, the main difference between reticulocyte and erythrocyte is structure and function.

References:

1. “Reticulocyte Count: Medlineplus Medical Test.” MedlinePlus, U.S. National Library of Medicine.
2. “Red Blood Cell.” Encyclopædia Britannica, Encyclopædia Britannica, Inc..  

Image Courtesy:

1. “Reticulocytes Human Blood Supravital Stain.” By Ed Uthman – Own work (CC BY 3.0) via Commons Wikimedia
2. “1903 Shape of Red Blood Cells” By OpenStax College – Own Work (CC BY 3.0) via Commons Wikimedia