What physiological response occurs during anaphylactic shock?

Anaphylactic shock is a severe and potentially life-threatening allergic reaction that triggers a number of physiological responses in the body. One of the hallmark features of this condition is the dilation of blood vessels, known as vasodilation. This process leads to a significant decrease in blood pressure, causing inadequate blood flow to vital organs, which can be fatal if not treated promptly.

When anaphylaxis occurs, the body releases large amounts of histamines and other chemicals in response to an allergen. Histamine causes blood vessels to widen and become more permeable, resulting in swelling and fluid loss from the bloodstream. This dilation contributes to the overall symptomatology of anaphylaxis, including the potential for shock.

Other physiological responses associated with anaphylactic shock do include airway constriction, rapid pulse, and sometimes hyperthermia; however, these do not define the primary characteristic of anaphylactic shock like the dilation of blood vessels does. The rapid pulse may occur as the body compensates for low blood pressure, while constriction of airways is a critical concern due to swelling in the respiratory tract. Hyperthermia can occur in some severe allergic reactions but is not a defining feature of anaphylactic shock, which is primarily characterized by cardiovascular collapse due to