To have sufficient perfusion pressures to meet bodily needs, all of the following components need to be intact EXCEPT:

A. Intact vascular system.
B. Adequate pumping of the heart.
C. Absence of vascular tone.
D. Sufficient blood volume.

Answer: C. Absence of vascular tone.
The blood pressure is the amount of pressure exerted against the arterial wall during circulation. The systolic blood pressure is the measured force that is exerted during he contraction of the heart. Whereas the diastolic blood pressure si the pressure inside the artery when there is no contraction, or between contractions of the heart. The vessel's size plays a major role in the blood pressure. A loss of vascular tone results in vasodilation (dilation of the vessels), which will cause the resistance to decrease and the blood pressure to fall, causing hypoperfusion.