Final answer:
A lethal injection of potassium solution causes death by disrupting the electrolyte balance necessary for muscle and nerve cell function, which can lead to cardiac arrest and asphyxiation due to oxygen deprivation.
Step-by-step explanation:
Injection of a potassium solution into a person's blood can indeed be lethal. This is the case for a couple of reasons. First, the high levels of potassium can disrupt the delicate balance of electrolytes necessary for normal function of muscle cells, including cardiac muscle cells. Potassium helps to regulate the heartbeat by contributing to the electrical charge that drives muscle contraction. An injection that significantly alters potassium levels can disrupt the electrical activity of the heart, potentially leading to cardiac arrest.
Moreover, cells use a balance of sodium and potassium ions to control the flow of other substances in and out of the cell. A sudden influx of potassium could disrupt this balance, leading to a range of cellular malfunctions. In systems like the central nervous system, this could lead to severe outcomes as well, including the disruption of normal breathing patterns. This disruption often culminates in asphyxiation, or an insufficient supply of oxygen, resulting in a lethal outcome.