Final answer:
Neutrophils are the most common white blood cells, making up 50-70% of leukocytes, and are critical in defending against bacterial infections. They are granulocytes with a lobed nucleus and contain granules that stain with neutral dyes. They function as phagocytes, engulfing and destroying pathogens.
Step-by-step explanation:
Neutrophils Overview:
Neutrophils are the most numerous type of white blood cells and play a critical role in the body's defense against bacterial infections. They typically represent 50-70% of the total leukocyte (white blood cell) count in blood. Neutrophils are classified as granulocytes, due to the presence of fine granules in their cytoplasm that are visible with neutral stains. These granules contain substances important for the cell's immune functions. A neutrophil's diameter ranges from 10-12 µm, making them larger than red blood cells. The nucleus of a neutrophil is lobed, often with two to five lobes, with the number of lobes increasing as the cell ages. Older neutrophils, with more lobes, are referred to as "polys" or polymorphonuclear, whereas younger neutrophils with fewer lobes are known as "bands". Neutrophils provide a rapid, nonspecific defense mechanism, acting as phagocytic cells that engulf and destroy pathogens in the infected tissues.