Difference Between Monocytes and Lymphocytes

Introduction

Blood present in the human body is the fluid connective tissue that mainly serves the function of the transportation of the different nutrients, proteins, oxygen, and carbon dioxide. The two main types of cells that are present in human blood are red blood cells and white blood cells. The white blood cells which are also known as leukocytes are mainly responsible for providing defence mechanisms in the human body against different types of invaders. The white blood cells present in the human body can further be of 5 types. These five types of white blood cells are eosinophil, basophil, neutrophil, monocytes, and lymphocytes.

Monocytes

Monocytes are the largest type of white blood cell which can differentiate into dendritic cells or macrophages. Monocytes are also responsible for the action of adaptive immunity.

Monocytes are ovoid in shape and have agranulated cytoplasm containing nuclei. These cells are one of the types of mononuclear leukocytes which shelter as bean or kidney-shaped. The clearest distinction is that the nuclear envelope should be hyperbolic.

Monocytes comprise about two to ten per cent of all the leucocytes present in the human body and serve some of the major immune roles such as replenishing macrophages under normal conditions, and migration with approximately eight to twelve hours due to inflammatory signals from infection site in the tissues. At least half of the monocytes in an adult human being, are stored in the spleen. Monocytes are synthesized in the bone marrow from precursors called monoblasts. Monocytes stay in the blood for about 1-3 days after which they finally move to different tissues present in the body.

Monocytes mature into macrophages and dendritic cells. Macrophages protect tissues from foreign agents and are also suspected to be important in the formation of important organs such as the heart and brain in a fetus. Macrophages and dendritic cells together serve three main immune functions in the human body. The three main functions are phagocytosis, cytokine production, and antigen presentation.

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Lymphocytes

Lymphocytes are the main cells of lymph. The life span of lymphocytes ranges from a few months to several years. 20 to 40 per cent of all white blood cells in the blood are lymphocytes. The condition in which more than 40 per cent of the total white blood cells are present in the human body is known as lymphocytosis and the condition in which less than 20 per cent of the total white blood cells are present in the human body is known as lymphocytopenia.

The synthesis of lymphocytes takes place in the bone marrow. After synthesis, they are transported to different locations such as blood and lymph tissues. The size of a lymphocyte is similar to that of a red blood cell. It has a diameter of about 7 micrometres. Lymphocytes contain a large dark nucleus.

Different functions such as the formation of antibodies, attack on foreign micro-organisms in the body, and fighting against viral infection are performed by lymphocytes. There are two different types of lymphocytes. Two types of lymphocytes are T cells also known as killer cells, and B cells.

T cells directly attack and destroy virally infected cells and the cancer infected cells in the human body. On the other hand, B cells are responsible for the synthesis of antibodies against the viruses, bacteria, and toxins that have entered the human body.

Similarities between Monocytes and Lymphocytes

There are many similarities present between monocytes and lymphocytes. They are types of agranulocytes that keep circulating through the blood. Both of these play a major role in triggering an immune response against the foreign material or pathogen that could have entered the body. Both the cells perform their functions by releasing cytokines.

Differences between Monocytes and Lymphocytes

Basis of comparison	Monocytes	Lymphocytes
Shape of nucleus	Oval	Round
Amount	2-3 per cent of white blood cells.	20-40 per cent of white blood cells.
Size	Comparatively large	Comparatively small
Texture	Grainy and gritty	Smooth
Type of action	Destroy pathogen through phagocytosis	Produces antibodies

Conclusion

• Monocytes are ovoid in shape and have agranulated cytoplasm containing nuclei whereas lymphocytes have round shape nuclei.

• Macrophages and dendritic cells together serve these immune functions in the human body which are phagocytosis, cytokine production, and antigen presentation.

• Two types of lymphocytes are T cells also known as killer cells, and B cells.

• Both monocytes and lymphocytes play a major role in triggering an immune response against the foreign material or pathogen that could have entered the body

• The size of the monocyte is comparatively larger than the size of the lymphocytes.

• Monocytes destroy pathogens by the process of phagocytosis whereas lymphocytes serve the purpose by producing antibodies.

FAQs

Q1. What does the high number of lymphocytes in the body indicate?

Ans. The high number of lymphocytes in the body indicates that white blood cells in the body are coming into action in order to get rid of the pathogen that has possibly entered the body.

Q2. What does the low number of lymphocytes in the body indicate?

Ans. Several disorders such as bloodstream infections, septic shock, chemotherapy, and bone marrow disorder could be responsible for the low number of lymphocytes in the body.

Q3. What happens if the number of monocytes in the human body is low?

Ans. A low number of monocytes in the human body indicates more susceptibility to infections.

Q4. Which foods increase the count of monocytes in the human body?

Ans. Different anti-inflammatory foods such as olive oil, green leafy vegetables, tomatoes, fish, etc., are helpful in increasing the count of monocytes in the human body.

Q5. Can stress lead to a low count of monocytes in the human body?

Ans. Yes, acute or prolonged stress can lead to a decrease in the count of monocytes the in human body.

Q6. Can cancer lead to a low count of monocytes in the human body?

Ans. Yes, all cancer that invades the bone marrow can be responsible for low monocyte count.