Lymphocytes

Julen Lux Baranano

edited by

Joshua Klemt,

1. Definition

Lymphocytes are a type of white blood cell (leukocyte) that play a central role in the adaptive immune system, responsible for identifying and defending against specific pathogens like viruses and bacteria. They account for 20-40% of total leukocytes in the blood.

2. Classification

Lymphocytes are classified into three main subtypes:

B Lymphocytes (B Cells)
- Percentage: 10-20% of total lymphocytes
- Function: Produce antibodies to neutralize pathogens. B cells are crucial for humoral immunity, generating memory cells to recognize specific antigens in future infections
T Lymphocytes (T Cells)
- Percentage: 60-80% of total lymphocytes
- Function: Key players in cell-mediated immunity, they attack infected or cancerous cells directly. Subtypes include:
  - Helper T cells (CD4+): Activate other immune cells
  - Cytotoxic T cells (CD8+): Destroy infected cells
Natural Killer Cells (NK Cells)
- Percentage: 5-10% of total lymphocytes
- Function: Part of the innate immune system, NK cells recognize and kill virus-infected or cancerous cells without the need for prior activation by antigens

3. Physiology

Normal Range: 1,000 to 4,800 lymphocytes per microliter (µL) of blood
Percentage in Blood: Lymphocytes make up 20-40% of all leukocytes in the blood
Lymphocytosis: high lymphocyte count
Lymphopenia: low lymphocyte count

Was this article helpful?

Specialty

histology, immunology, Physiology

Keywords

Last edit:

2024-12-26 19:21:45

Important Notice

The content provided in DocAtlas is intended solely for educational and informational purposes. It is not a guide for diagnosis, treatment, or medical decision-making. As an open platform, the information in DocAtlas may be subject to inaccuracies, errors, or omissions, and it is important to review and cross-check all content with other reputable sources before making any medical or clinical decisions.

The material in DocAtlas does not replace professional medical advice, diagnosis, or treatment from qualified healthcare providers. Users should consult with their doctor, pharmacist, or other healthcare professionals for specific advice tailored to their individual conditions.

DocAtlas and its authors make no warranties regarding the completeness, accuracy, or reliability of the information contained within and are not liable for any harm, damage, or adverse effects arising from the use or misuse of the content. Users are responsible for ensuring that they verify and critically evaluate all information before applying it in any medical or clinical context.