[Biology Class Notes] on Difference Between Monocytes and Lymphocytes Pdf

The human body is a complex system that requires a good amount of transportation and circulation to be taken good care of. To ensure that this body stays safe and healthy, a lot of things happen in the background involuntarily that keep the entire body alive. It is the cells in our body that keep us alive and healthy for the most part and absolutely take care of our body even when we are sleeping. 

This article is made in order to make sure that the main differences between what monocytes are and what lymphocytes are highlighted and are explained properly. To make sure that you are not getting confused, we suggest that you are taking notes throughout the reading time of this article. 

This is a necessity because no matter what happens, you will be able to revise all of these important topics and the differences between the two at any moment of the day. As a student, it is sometimes difficult to maintain school life with your everyday life which leads students to forget a lot of information that they should remember. This is why we suggest that students are always staying focused on their note-taking methods and use them here as well. 

The Human body has special types of cells known as white blood cells which float around the blood and help the immune system fight infections. On average, there are 4500 to 11000 WBC per microliter in the blood. There are five types of white blood cells namely:

  • Monocytes

  • Eosinophils

  • Basophils

  • Lymphocytes

  • Neutrophils

Monocytes

Monocytes are large cells that make 2-8% of the total white blood cell count in the blood. There are three subclasses of monocytes based on the phenotype receptors. Often they are found at the site of chronic infections. They are formed in the bone marrow and released into the peripheral blood.

Structure

Monocytes are amoeboids with prominent surface ruffles and measuring between 12-20 μm in diameter. When monocytes enter the tissue it differentiates into a macrophage. The cell shape varies depending on the type of the macrophage(i.e liver, spleen).

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Function

Monocytes have the ability to recognize danger signals through pattern recognition receptors. They are capable of ingesting infectious particles and other large particles but they cannot replace the function of Neutrophils which can remove and destroy infectious particles. Their major functions of monocytes are:

  • Phagocytosis – The cell uses its plasma membrane to engulf large particles.

  • Antigen Presentation – Initiation of adaptive immune responses.

  • Cytokine Production – Fundamental response to injury or infection.

 

Clinical Significance

An increased number of monocytes occurs when the body is facing chronic infections, blood disorders, stress, diabetes, autoimmune disorders, and certain cancers.

Excess monocytes result in a state called Monocytosis.

The deficiency of monocytes results in leukopenia called Monocytopenia.

Lymphocytes

This originates from the stem cells in the bone marrow and are found in blood and lymph tissue. They constitute around 28-48% of the white blood cells. There are two different types of lymphocytes namely; B(Bone-marrow) lymphocytes and T (Thymus) Lymphocytes commonly referred to as B-cells and T-cells. There is another type of lymphocyte called Natural Killer cells which detect and destroy abnormal tissue cells such as cancers. The B-cells make antibodies, which are proteins produced by the body to fight against foreign substances called antigens. They follow the lock and key mechanism wherein they produce one specific antibody to match with a specific antigen. When this happens the antigen is marked for destruction.

The T-cells help in destroying cancerous cells and cells affected by viruses.

Structure

A normal lymphocyte has a large dark stained, ovoid, or kidney-shaped nucleus with densely packed chromatin. It measures around 6-15μm in diameter.

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Function

The different types of B-cells and T- cells have specific roles to perform, below are a few functions of each:

  1. B-Cells

  • Memory B-Cells – Memory B cells start fast antibody responses when pathogens attack and they remain in the body for a longer duration and remember the previously attacked antigens and help the immune system to respond during future attacks.

  • Regulatory B-Cells – Regulatory B cells have anti-inflammatory effects on the body and prevent lymphocytes that cause inflammation. They also promote the production of regulatory T-cells.

  1. T-Cells

  • Memory T-Cells – They protect against previously found antigens

  • Regulatory T-Cells – They prevent autoimmune diseases, maintain tolerance to germs.

  • Killer T-Cells – They scan and kill the cells that are infected or have turned cancerous.

  • Helper T-Cells – They help other cells in the immune system to start and control the immune response to foreign substances.

Clinical Significance

When there is an increased number of lymphocytes in the blood it results in a condition called Lymphocytes. A high count of lymphocytes in the blood indicates that the body is fighting against infection or inflammation.

A low level of lymphocytes can lead to a condition called Lymphopenia or Lymphocytopenia. Lymphopenia can be acquired along with other diseases or may be inherited.

Difference between Monocytes and Lymp
hocytes

Basis of Comparison

Monocytes

Lymphocytes

Percentage count

2-8% of circulating WBC’s.

28-28% of circulating WBC’s.

Lifespan

Monocytes are present in the blood for a span of 24 hours.

On average most Lymphocytes are short-lived. They may remain for a few weeks or months but some lymphocytes may remain in the blood for years.

Immunity type

Monocytes are involved in  Innate immunity where the defense mechanisms come into play immediately or within hours of infection or injury when the antigen appears.

Lymphocytes are part of adaptive immunity or acquired immunity which uses specific antigens to mount an immune response.

Size and shape

Large-sized may be spherical or ameboid.

The size varies while encountering an infectious agent.

Cell cytoplasm 

In monocytes, the cytoplasm is opaque, blue-gray in color with fine lilac granules.

Lymphocytes have clear, transparent, and sky blue coloured cytoplasm without granules.

Vacuoles

Infrequent vacuoles.

Frequent vacuoles.

Foreign body destruction

Monocytes destroy foreign substances by phagocytosis.

Lymphocytes destroy the pathogens by producing antibodies.

Subtypes

Dendritic cells and macrophages are two types of monocytes

T-cells, B-cells, and Natural Killer cells are the 3 types of lymphocytic cells.

Keep this table handy and next to you to make sure that you always are able to know what the main differences between Monocytes and Lymphocytes are. By using this table and following the pattern given here, you will be able to figure out all the important things and factors on the basis of which the two terms are being differentiated upon. Therefore make sure that all the important things are being kept in handy from this article for last-minute revision. 

Conclusion

The human body is a complex machine that is protected by every single thing that lives inside it. They not only help in making sure that the entire body is safe but is also healthy and is away from all diseases. The goal of this article was to present the major differences between the two terms very effectively so that it leaves no space for any doubt. However, students can still easily find answers to their doubts by simply dropping comments at the bottom of this article. 

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