What electrolyte inactivates troponin and allows actin and myosin to form a bridge enabling fibers to contract?

Choice A rationale

Magnesium plays a role in various cellular functions, including enzyme activity and muscle contraction, but it does not directly inactivate troponin to enable actin and myosin interaction.

Choice B rationale

Sodium is essential for action potential generation and nerve impulse transmission but does not directly influence troponin activity or muscle contraction through actin and myosin bridge formation.

Choice C rationale

Potassium is critical for maintaining cellular resting membrane potential and repolarization of cells but does not play a direct role in inactivating troponin to facilitate muscle contraction.

Choice D rationale

Calcium is the electrolyte that inactivates troponin, allowing actin and myosin to form cross-bridges and contract muscle fibers. Calcium binds to troponin, causing a conformational change that exposes binding sites for myosin on actin filaments.

Choice A rationale

Poor self-care is not directly associated with reddened, bleeding gums in this context.

Choice B rationale

While aspirin can cause bleeding issues, the context here is related to seizure disorder and phenytoin.

Choice C rationale

Phenytoin, an anticonvulsant used to manage seizures, can cause gingival hyperplasia, leading to reddened and bleeding gums.

Choice D rationale

Hepatotoxicity is related to liver damage and does not present with reddened, bleeding gums.