Lymphocytes

Definition

Lymphocytes are a type of white blood cell integral to the immune system, primarily involved in adaptive immunity. They include B cells, T cells, and natural killer (NK) cells.

5 Must Know Facts For Your Next Test

1. Lymphocytes play a crucial role in hypersensitivity reactions by mediating both immediate and delayed responses.
2. B cells produce antibodies that can contribute to allergic reactions and autoimmune diseases.
3. T cells are essential for cell-mediated immunity and are involved in type IV hypersensitivity (delayed-type hypersensitivity).
4. Natural killer (NK) cells can kill virus-infected cells and tumor cells without prior sensitization.
5. Dysregulation of lymphocyte function can lead to various hypersensitivities and autoimmune disorders.

Review Questions

• What roles do B cells and T cells play in hypersensitivity reactions?
• How do NK cells differ from B and T lymphocytes in their immune function?
• Describe the involvement of lymphocytes in type IV hypersensitivity.

Related terms

B Cells:

A type of lymphocyte that produces antibodies as part of the humoral immune response.

T Cells:

A type of lymphocyte involved in cell-mediated immunity, including helper, cytotoxic, regulatory subsets.

Hypersensitivity:

An exaggerated immune response to an antigen leading to tissue damage or disease.