What is the function of basophils in the bloodstream?

Basophils play a significant role in the body's immune response, particularly in relation to allergic reactions. They are a type of white blood cell that is involved in the inflammatory response and are known for their ability to release histamine and other mediators when activated. This release contributes to the symptoms associated with allergies, such as increased blood flow, swelling, and changes in vascular permeability.

During an allergic response, basophils can be triggered by allergens which lead to their activation and subsequent degranulation. This process releases substances like histamine, which help to promote inflammation and recruit other immune cells to the site of the allergen exposure. Therefore, the primary function of basophils in the bloodstream revolves around their role in modulating and mediating allergic responses, making the choice that identifies their function in this context clear and accurate.

While other options like secretion, oxygen transport, and extracellular fluid (ECF) regulation are important functions in the body, they don't specifically align with the primary function of basophils, which is integral to the immune mechanism related to allergies and inflammation.