What is the body's primary response to tissue anoxia caused by carbon monoxide poisoning?

In the context of carbon monoxide poisoning, the primary response of the body to tissue anoxia—resulting from reduced oxygen delivery due to carbon monoxide binding to hemoglobin—is increased respiratory rate. When carbon monoxide is present in the bloodstream, it competes with oxygen for binding sites on hemoglobin, leading to reduced oxygen transport. As a compensatory mechanism, the body attempts to increase the availability of oxygen by stimulating the respiratory system to enhance breathing. This increased respiratory rate allows for potentially more oxygen intake and the removal of carbon dioxide, which is crucial for cellular metabolism and sustaining life in the face of anoxia.

In contrast, increased metabolism typically results from the body trying to compensate for various stresses or energy demands but does not specifically relate to anoxia caused by carbon monoxide. Elevated blood pressure may occur as a secondary response to stress but is not the primary reaction to tissue anoxia in this scenario. Decreased body temperature does not fit the body's immediate compensatory actions as it usually indicates a systemic response to various conditions, rather than a direct response to hypoxia caused by carbon monoxide. Thus, the answer that captures the primary physiological response to anoxia from carbon monoxide exposure is an increased respiratory rate.