Which blood cell fits the following description: multi-lobed nucleus, inconspicuous cytoplasmic granules, most common type of blood cell except for red blood cells?
A. neutrophil
B. eosinophil
C. basophil
D. lymphocyte
The correct answer and explanation is :
The correct answer is A. neutrophil.
Explanation:
Neutrophils are a type of white blood cell and are part of the body’s immune system. They are the most common type of white blood cell, comprising about 50-70% of the total white blood cell count in most people. Neutrophils are essential for the immune response, particularly in fighting bacterial infections.
Key characteristics:
- Multi-lobed nucleus: Neutrophils have a distinctive, multi-lobed nucleus, which is one of their defining features. The nucleus typically appears segmented into 2-5 lobes, which is why neutrophils are also referred to as “polymorphonuclear leukocytes” (PMNs).
- Inconspicuous cytoplasmic granules: The cytoplasm of neutrophils contains small granules, which are not as prominent as those in other granulocytes like eosinophils or basophils. These granules contain enzymes and antimicrobial substances that help neutrophils to fight infections.
- Most common white blood cell: Neutrophils are the most numerous of the white blood cells, second only to red blood cells in number. They are an essential part of the body’s first line of defense against infections, especially bacterial infections.
Neutrophils function by phagocytizing (engulfing and digesting) pathogens such as bacteria, dead cells, and foreign particles. They are usually the first responders to infection, rapidly migrating to the site of infection in response to signals from the immune system.
Other choices:
- B. eosinophil: Eosinophils have a bi-lobed nucleus and prominent granules in the cytoplasm, primarily involved in allergic reactions and parasitic infections, not bacterial defense.
- C. basophil: Basophils have a bi-lobed nucleus and dark-staining granules, typically involved in allergic responses and inflammation, but they are much less common than neutrophils.
- D. lymphocyte: Lymphocytes have a large, round nucleus and minimal cytoplasm. They are key players in the adaptive immune system but do not have multi-lobed nuclei.
Thus, the cell described in the question is a neutrophil.