Arteries have one-way valves that prevent the backflow of blood.

Your patient who was in a head-on MVC has asymmetric blood pressure measurements in the upper extremities, widened pulse pressure, and diminished lower extremity pulses. You suspect:

A) traumatic asphyxia. B) tear of the aorta. C) cardiac contusion. D) neurogenic shock.

Automaticity is the ability of cardiac pacemaker cells to:

A) spontaneously generate their own electrical impulses without external stimulation B) respond to an electrical stimulus C) receive an electrical impulse D) cause cardiac muscle contraction