What is the Difference Between Neutrophils and Leukocytes

The main difference between neutrophils and leukocytes is that the neutrophils are a type of white blood cells that can destroy pathogens via phagocytosis whereas the leukocytes are white blood cells that play a critical role in the immunity. Furthermore, neutrophils are one of the three types of granulocytes while leukocytes comprise both granulocytes and agranulocytes. 

Neutrophils and leukocytes are white blood cells that circulate throughout the body via blood. Neutrophils, eosinophils, basophils, lymphocytes, and monocytes are the types of leukocytes. 

Key Areas Covered 

1. What are Neutrophils
     – Definition, Features, Function
2. What are Leukocytes
     – Definition, Types, Function
3. What are the Similarities Between Neutrophils and Leukocytes
     – Outline of Common Features
4. What is the Difference Between Neutrophils and Leukocytes
     – Comparison of Key Differences

Key Terms 

Granulocytes, Immunity, Leukocytes, Lymphocytes, Neutrophils, White Blood Cells

What are Neutrophils 

Neutrophils are one of the three types of granulocytes found in the blood. They contain a multi-lobed nucleus. They account for 62% of white blood cells in the circulation. Neutrophils are one of the first types of white blood cells that migrate to the site of infection. This migration occurs in response to cytokine signals in a process called chemotaxis.  

Figure 1: A Neutrophil

The main function of neutrophils is to destroy pathogens by phagocytosis. Hence, neutrophils engulf pathogens including bacteria and fungi found in the extracellular matrix by endocytosis. Here, the plasma membrane surrounds the pathogen, forming a vesicle. This vesicle is trafficked into a lysosome, which contains digestive enzymes for the degradation of the pathogen. Finally, neutrophils eliminate the waste of the digestion by exocytosis.  

What are Leukocytes 

‘Leukocytes’ is another name for white blood cells. They are the only type of nucleated cells in the blood. Depending on the presence of granules in the cytoplasm, there are two types of leukocytes. They are; granulocytes and agranulocytes. The three types of granulocytes are neutrophils, eosinophils, and basophils. Lymphocytes and monocytes are the two types of agranulocytes.  

Figure 2: Leukocytes

Looking at their functions; leukocytes are involved in both innate and adaptive immunity. In innate immunity, granulocytes and monocytes trigger a non-specific immune response against pathogens. They destroy pathogens by phagocytosis and present the antigens of the pathogens to the lymphocytes. Therefore, they serve as antigen presenting cells. On the other hand, they mediate inflammation and allergic responses. In addition, lymphocytes are involved in the adaptive immunity by triggering a pathogen-specific immune response. They recognize the antigens presented by the antigen-presenting cells and a type of lymphocytes called the B cells, which produces antibodies. Moreover, T cells, which are another type of lymphocytes, trigger cell-mediated immune response. 

Similarities Between Neutrophils and Leukocytes 

• Neutrophils and leukocytes are white blood cells that circulate throughout the body via the blood. 
• Both contain a nucleus. 
• Also, both their main function is to protect the body against pathogens. 

Difference Between Neutrophils and Leukocytes 

Definition 

Neutrophils refer to a common type of white blood cell important in fighting off infections while leukocytes refer to colourless cells which circulate in the blood and body fluids, involving in counteracting foreign substances and disease. Hence, this is the basic difference between neutrophils and leukocytes.

Correspondence 

Furthermore, neutrophils are a type of leukocytes while neutrophils, eosinophils, basophils, lymphocytes, and monocytes are types of leukocytes. 

Granulocytes/Agranulocytes 

Another difference between neutrophils and leukocytes is that neutrophils are a type of granulocytes while leukocytes contain both granulocytes and agranulocytes. 

Lobes in the Nucleus 

Moreover, neutrophils may have 2-5 lobes in the nucleus while the nucleus of leukocytes contains either a single lobe or many lobes. 

Function 

The main difference between neutrophils and leukocytes is their respective functions. The main function of neutrophils is to destroy pathogens via phagocytosis while the main functions of leukocytes are pathogen recognition, antigen presentation, inflammation mediation, and pathogen destruction. 

Type of Immunity 

Neutrophils are involved in innate immunity while leukocytes are involved in both innate and the adaptive immunity. This is another difference between neutrophils and leukocytes.

Conclusion 

In summary, neutrophils are a type of white blood cells responsible for the destruction of pathogens via phagocytosis. On the other hand, leukocytes refer to white blood cells in the circulation including neutrophils, basophils, eosinophils, lymphocytes, and monocytes. They are responsible for both innate and adaptive immune responses of the body. Therefore, the main difference between neutrophils and leukocytes is their correspondence.

Reference:

1. “Boundless Anatomy and Physiology.” Lumen, Available Here

Image Courtesy:

1. “Hyperlobated Neutrophil” By Ed Uthman (CC BY 2.0) via Flickr
2. “Blausen 0909 WhiteBloodCells” By BruceBlaus. When using this image in external sources it can be cited as:Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia