Refractory Period of Heart

1			During the normal cardiac cycle, the ventricle contracts:
			A)	before the atria contract.
			B)	at the same time as the atria contract.
			C)	after the atria contract.
2			Look at your record when a shock produced an extra ventricle contraction. Was the extra contraction produced when the shock was applied before the normal ventricle contraction?
			A)	yes.
			B)	no.
			C)	sometimes.
3			Was an extra contraction produced when the shock was applied to the ventricle when the ventricle was contracting normally?
			A)	yes.
			B)	no.
			C)	sometimes.
4			Was an extra contraction produced when the shock was applied after the normal ventricle contraction?
			A)	yes.
			B)	no.
			C)	sometimes.
5			If extra ventricle contractions were produced when the ventricle was relaxing, this means that:
			A)	the ventricle filled with some blood before the extra contraction.
			B)	the ventricle filled with the same amount of blood as normal before the extra contraction.
			C)	the ventricle did not have time to fill with any blood before the extra contraction.