Excitation-contraction coupling is a series of events that occur after the events of the neuromuscular junction have transpired. The term excitation refers to which step in the process? A) Excitation refers to the release of calcium ions from the sarcoplasmic reticulum. B) Excitation refers to the shape change that occurs in voltage-sensitive proteins in the C) Excitation, in this case, refers to the propagation of action potentials along the sarcolemma. D) Excitation refers to the propagation of action potentials along the axon of a motor neuron.

Americans often speak of their country as one of several large regions.  these regions are cultural units rather than governmental units --  formed by history and geography and shaped by the economics, literature and folkways that all the parts of a region share. what makes one region different from another? a region's multicultural heritage as well as distinct demographic characteristics like age and occupation make regions different and special. within several regions, language is used differently and there are strong dialects. there are also differences in outlook and attitude based on geography.