Which of the following substances/cells is found in the gingival epithelium?

The pacemaker that fires at 20 to 40 beats per minute is the:

A) Purkinje's network B) Bundle of His C) AV node D) SA node

If a patient complains of an aching pain in the chest, the complaint would be considered part of the past, family, and social history (PFSH)

Indicate whether this statement is true or false.