What Is Lymphocytes

Hello brother myself Arjun, what is lymphocyte and what is the function of lymphocytes?

A lymphocyte is one of the subtypes of white blood cell in a vertebrate's immune system. Lymphocytes include natural killer cells

They are the main type of cell found in lymph, which prompted the name lymphocyte.

Types
Three major types of lymphocyte
T cells
B cells
Natural killer

T cells and B cells
T cells and B cells are the major cellular components of the adaptive immune response. T cells are involved in cell-mediated immunity, whereas B cells are primarily responsible for humoral immunity. T cells and B cells is to recognize specific “non-self” antigens, during a process known as antigen presentation.

Natural killer cells
NK cells are a part of the innate immune system and play a major role in defending the host from both tumors and virally infected cells. NK cells are activated in response to a family of cytokines called interferons.

Characteristics
Microscopically, in a Wright's stained peripheral blood smear, a normal lymphocyte has a large, dark-staining nucleus with little to no eosinophilic cytoplasm. In normal situations, the coarse, dense nucleus of a lymphocyte is approximately the size of a red blood cell.
Some lymphocytes show a clear perinuclear zone (or halo) around the nucleus or could exhibit a small clear zone to one side of the nucleus

Phenotypic Marker
CD16 CD56 but not CD3
TCRαβ, CD3 and CD4
TCRαβ, CD3 and CD8
TCRγδ and CD3
MHC class II, CD19 and CD21

Normal Range Of Lymphocyte Count
In blood tests, the lymphocyte level can be analysed, with their value will be seen in the CBC section. Its value is calculated per millilitre of blood, the normal range of lymphocytes is between 1300 and 4000 cells / ml.

High lymphocyte counts
Young children (from 0 to 4 years old) are considered to have lymphocytosis from when counts are above 9000 per millilitre whereas high counts in children from 5 to 12 years old are considered above 7000 per millilitre.

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Answered By StudyChaCha Member