Difference Between Polymorphonuclear and Mononuclear Cells

The key difference between polymorphonuclear and mononuclear cells is that polymorphonuclear cells have a nucleus with several lobes while mononuclear cells have a round nucleus which has only one lobe.

Blood consists of three major types of blood cells: erythrocytes (red blood cells), leukocytes (white blood cells) and thrombocytes (platelets). Leukocytes are the main cells of the immune system of our body since they protect us from invading pathogens that could disrupt the normal functioning. All leukocytes originate from the multipotent hematopoietic stem present in the bone marrow. Moreover, leukocytes circulate in the bloodstream and the lymphatic system. Also, normal blood has a leukocyte count of 4500-11000 cells per microliter of blood. Furthermore, there are two types of leukocytes depending on the presence or absence of granules in the cytoplasm. Granulocytes have granules in their cytoplasm while agranulocytes lack granules. Furthermore, based on the shape of the nucleus, there are two types of leukocytes as polymorphonuclear cells and mononuclear cells.

CONTENTS

1. Overview and Key Difference
2. What are Polymorphonuclear Cells
3. What are Mononuclear Cells
4. Similarities Between Polymorphonuclear and Mononuclear Cells
5. Side by Side Comparison – Polymorphonuclear vs Mononuclear Cells in Tabular Form
6. Summary

What are Polymorphonuclear Cells?

Polymorphonuclear cells are a group of white blood cells. As the name implies, these cells have a varying shaped nucleus, which has several lobes. Furthermore, they have granules in the cytoplasm. Hence, they are granulocytes or granular leukocytes.

Furthermore, this category of leukocytes includes neutrophils, eosinophils and basophils. Among these three different types, neutrophils are the most abundant polymorphonuclear cells, and they consist of a nucleus that has three segments.

What are Mononuclear Cells?

Mononuclear cells are the second type of leukocytes. They have a round shape nucleus. Characteristically, the nucleus has only one lobe. Moreover, these cells lack granules in their cytoplasm. Hence, they belong to the group of agranulocytes or agranular leukocytes.

Furthermore, monocytes and lymphocytes (T cells, B cells and natural killer cells) are the two main types of mononuclear cells present in our immune system.

What are the Similarities Between Polymorphonuclear and Mononuclear Cells?

• Polymorphonuclear and mononuclear cells are two types of leukocytes based on the nucleus structure.
• Both these types of cells are nucleated cells present in the bloodstream.
• Moreover, they are immune cells.
• They also protect us from pathogens and foreign agents.

What is the Difference Between Polymorphonuclear and Mononuclear Cells?

Polymorphonuclear cells are the leukocytes that have a segmented nucleus, while mononuclear cells are the leukocytes that have a round shape nucleus, which is unilobed. So, this is the key difference between polymorphonuclear and mononuclear cells. Moreover, granules are present in the polymorphonuclear cells, while granules are absent in mononuclear cells. Therefore, this is also a difference between polymorphonuclear and mononuclear cells.

Summary – Polymorphonuclear vs Mononuclear Cells

Leukocytes are two types based on the nucleus structure. They are polymorphonuclear cells and mononuclear cells. Polymorphonuclear cells have a nucleus which has several segments or lobes while mononuclear cells have a round shape nucleus. Thus, this is the key difference between polymorphonuclear and mononuclear cells. Furthermore, polymorphonuclear cells have granules in their cytoplasm, but mononuclear cells lack granules. Neutrophils, eosinophils and basophils are polymorphonuclear cells while monocytes and lymphocytes are mononuclear cells.

Reference:

1. “Granulocyte.” Wikipedia, Wikimedia Foundation, 15 July 2019, en.wikipedia.org/wiki/Granulocyte.

Image Courtesy:

1. “Blausen 0676 Neutrophil (crop)” By Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436 (CC BY-SA 4.0) via Commons Wikimedia
2. “Blausen 0624 Lymphocyte B cell (crop)” By Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436 (CC BY-SA 4.0) via Commons Wikimedia