Final answer:
The primary protective action of a granulocyte neutrophil is phagocytosis, where they engulf and digest pathogens in infected tissues. They also release cytokines, which help regulate immune responses. The correct option is 1.
Step-by-step explanation:
The protective action of the granulocyte neutrophil is primarily phagocytosis. Neutrophils are a type of white blood cell that form an essential part of the innate immune system. As phagocytic cells, neutrophils migrate from the bloodstream to infected tissues, driven by chemotaxis.
There, they help defend the body by engulfing and digesting pathogens. Neutrophils contain granules filled with enzymes and other substances useful for breaking down these pathogens. After a neutrophil engulfs just a few pathogens, it typically dies, highlighting their sacrificial role in the immune response.
Additionally, neutrophils release cytokines that contribute to the overall defense mechanism against infection. These cytokines can amplify the immune response by recruiting other immune cells to the site of infection and are involved in the regulation of the immune system.
Despite their role in cytokine production, the primary function of neutrophils in protecting the body is through phagocytosis, not cytokine release, antibody production, or tissue repair. Hence, 1 is the correct option.