Which of the following white blood cells are granulocytes?
A) neutrophils and lymphocytes
B) eosinophils and monocytes
C) lymphocytes and monocytes
D) basophils and neutrophils
The correct answer and explanation is:
The correct answer is D) basophils and neutrophils.
Granulocytes are a type of white blood cell that contains granules in their cytoplasm. These granules are filled with enzymes and other substances that play a crucial role in immune responses, particularly in fighting infections. Granulocytes can be classified into three main types based on the staining characteristics of their granules:
- Neutrophils: These are the most abundant type of white blood cells and are primarily involved in the defense against bacterial infections. Neutrophils contain granules that are neutral in color when stained and are capable of phagocytosis, the process of engulfing and destroying pathogens. They are usually the first responders to sites of infection.
- Eosinophils: These cells are involved in combating parasitic infections and also play a role in allergic reactions. The granules in eosinophils stain with acidic dyes, giving them a reddish or pinkish hue. Eosinophils release toxins to destroy parasites and modulate inflammatory responses.
- Basophils: These are the least common type of granulocytes and have large granules that stain dark purple with basic dyes. Basophils are involved in allergic reactions and release histamine, which helps to dilate blood vessels and promote inflammation during allergic responses.
The other cells listed in the options, lymphocytes and monocytes, are agranulocytes, meaning they do not have visible granules in their cytoplasm. Lymphocytes are key players in the adaptive immune response, and monocytes differentiate into macrophages or dendritic cells, which help in the phagocytosis of pathogens.
In summary, neutrophils and basophils are the granulocytes, characterized by their distinct granules, which are essential for their immune functions.