MEAS 238/239 - Chapter 49 || A+ Graded Already.

Depolarization correct answers The electrical impulse that initiates a chain reaction resulting in contraction. Sinoatrial (SA) node (pacemaker) correct answers Electrical impulses occur at a rate of 60 to 100 beats per minute, initiating the heartbeat with an electrical impulse that causes depolarization. Atrioventricular (AV) node correct answers Delays the electrical impulse to allow for the atria to complete their contraction and ventricles to fill before the next contraction; also serves as a secondary pacemaker if the SA node fails. Bundle of His (AV bundle) correct answers Conducts electrical impulses from the atria to the ventricles. Bundle branches correct answers Conduct impulses down both sides of the interventricular septum. Purkinje fibers (network) correct answers Distribute the electrical impulses throughout the right and left ventricles. P wave correct answers Atrial depolarization with resulting atrial contraction. QRS complex correct answers Ventricular depolarization and resulting ventricular contraction (larger than the P wave); atrial repolarization occurs (not seen). T wave correct answers Ventricular repolarization. U wave correct answers Repolarization of the bundle of His and Purkinje fibers (not always seen); may be seen in instances of electrolyte imbalance. PR interval correct answers Beginning of atrial depolarization to the beginning of ventricular depolarization. QT interval correct answers Period of time from the start of ventricular depolarization to the end of ventricular repolarization. ST segment correct answers Time between ventricular depolarization and the beginning of ventricular repolarization. The most common electrocardiograph is? correct answers 12-lead Each of the standard leads monitors? correct answers 2 limb electrodes; bipolar leads. The augmented leads monitor? correct answers One limb electrode and a point midway between two other limb electrodes; unipolar leads.