What health hazard is presented by electrical current flowing through the body?

When electrical current flows through the body, it poses multiple health hazards, all of which are accurately described in the options provided.

One significant risk is tissue heating. When current flows through biological tissues, it generates heat due to the resistance of the tissue, potentially leading to thermal injury. This can cause burns or damage to internal organs, especially if the current is high or passes through critical areas.

Another health hazard is the potential disruption of the electrical functions of cells. The human body relies on electrical signals for many physiological processes. An external electrical current can interfere with these signals, leading to malfunctions of vital systems like the heart, which can result in arrhythmias or cardiac arrest.

Additionally, electrical current can cause involuntary muscle contractions. This is because the nerves that stimulate muscle contractions can be affected by external currents, leading to spasms or uncontrollable movements, which could be dangerous in certain situations, such as near hazardous equipment.

Since all these effects—thermal injury, disruption of cellular electrical activity, and involuntary muscle contractions—are valid and critical to understanding the risks associated with electrical current, the comprehensive answer is that all these choices are correct. This highlights the importance of safety measures when dealing with electrical systems to mitigate these various health hazards.