Which part of a modern firearm has the same function as the lock on a muzzleloader? safety trigger action barrel?

On a modern firearm, the feature that functions like the lock on a muzzleloader is the safety. The safety was added to modern guns to prevent them from accidentally firing, although it should be noted that a safety is a man-made mechanical device which makes it subject to failure at times.

Calcinosis is the diagnostic term that means an abnormal buildup of calcium on the kneecap (patellar) surface. it is a term uses to describe a group of disorders in which calcium deposits form in the skin. it is also referred to the abnormal deposit of calcium phosphate.