Emergency Medical Technician (EMT) Intermediate Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

Basophils play a crucial role in the immune response, particularly during allergic reactions. They release substances that contribute to the inflammation and allergic response in the body. Histamines, one of the main components released by basophils, lead to increased blood flow and vascular permeability, which can result in symptoms commonly associated with allergies, such as swelling and redness.

Heparin, another substance released by basophils, functions as an anticoagulant, inhibiting blood clotting. This helps maintain blood flow and prevents clot formation in areas of inflammation, allowing immune cells greater access to the affected tissues. This dual action of releasing histamines to enhance inflammatory response and heparin to facilitate smooth blood flow is critical in managing the body's reaction to allergens.

Other options provided do not accurately describe the roles of the substances released by basophils during allergic reactions. For example, while eosinophils are indeed involved in allergic responses, they are not released by basophils. Furthermore, the concept of basophils releasing antigens is not correct, as antigens are typically substances that provoke an immune response rather than being released by immune cells.