The white half-moon-shaped area at the base of a nail is called a(n) _______________ and contains very active keratinocytes. 

The joint formed by the articulation between the talus and calcaneus, the _______________ joint, is sometimes referred to as the lower ankle joint because it moves with the talocrural joint during ________________ and _________________

Fill in the blank(s) with the appropriate word(s).

You are aggressively ventilating an adult patient with a bag-valve mask when you notice that his previously strong pulse is getting weaker. You should:

A) reduce the volume of the ventilations. B) begin chest compressions. C) increase the concentration of oxygen. D) reduce the concentration of oxygen.