Asphyxiation is defined as which of the following?

Asphyxiation refers specifically to the condition caused by an interruption of normal breathing, which can lead to insufficient oxygen intake and an accumulation of carbon dioxide in the body. When breathing is obstructed or halted, the body cannot efficiently exchange gases, resulting in hypoxia (low oxygen) and potential unconsciousness or death if the situation is not corrected.

The other choices involve different physiological issues; for instance, blockage of blood flow pertains to circulatory problems, a decrease in heart rate is related to an irregular heartbeat or bradycardia, and an increase in carbon dioxide levels typically occurs as a consequence of asphyxiation rather than defining it. Therefore, the correct identification of asphyxiation as an interruption of normal breathing is crucial for understanding its medical implications and the urgency required in such situations.