After the peak of action potential, called spike potential, the permeability of the membrane to Na+ decreases, while it becomes more permeable for K+ which rapidly diffuses out from the cytoplasm to extracellular fluid due to electrochemical gradient. Soon, this part of membrane regains its original polarity and becomes electropositive on outside and electronegative on inside. This is known as REPOLARIZATION and the nerve fibre is called repolarized nerve fibre. A repolarized nerve fibre has same polarity as that of a polarized nerve fibre but has different ionic distribution. It has more K+ outside and more Na+ inside. The repolarized nerve fibre undergoes a refractory period of a few milliseconds during which the original ionic distribution is restored by a sodium pottasium exchange pump which actively transport sodium ions out and pottasium ion in.
Depolarization is the act of contracting
Polarizing is "relaxing" can be seen by the T-wave in an EKG
The T wave represents Ventricular Repolarization.
Atrial repolarization coincides with the QRS complex on the ECG. The T-wave corresponds to Ventricular repolarization. 'with tHE t-wave' <-- WRONG
The QRS complex
It is on page 374 of your lab book assuming this is the same question that came out Lab 28 in the Ninth Edition of Seeley's Anatomy & Physiology. The atrial repolarization occurs during ventricualr depolarization and is masked by the larger QRS complex. I actually did my homework :)
Your heart, that is part of the cardiovascular system is tested with EKG or ECG test.
adrenaline speeds the heart and the ecg will reflect that.
The portion of the ECG that indicates ventricular repolarization or recovery is the t wave. It is the wave found after the QRS complex (Ventricular depolarizaton) in a normal ECG
The wave indicating atrial repolarization wave is hidden by the QRS complex. Ventricular repolarization is indicated by the T wave.
the T wave, which indicates ventricular repolarization
the T wave, which indicates ventricular repolarization.
Atrial repolarization coincides with the QRS complex on the ECG. The T-wave corresponds to Ventricular repolarization. 'with tHE t-wave' <-- WRONG
It represents the repolorization of the ventricles. The ventricles must reset electrically after contracting. In a normal Sinus Rhythm the p wave comes first. Then the QRS complex which is the largest part of the heartbeat will come less than .2 seconds later. The QRS complex usually lasts less than .12 seconds. The final bump is (usually) the T wave.
P wave - represents atrial depolarization (contraction) QRS complex - ventricular depolarization T wave - ventricular repolarization (relaxation) atrial repolarization is "buried" within the QRS Complex
P waves represent the atrial depolarization. QRS complex represent the ventricular depolarization. T waves represent the ventricular repolarization.
The atrial repolarization occurs during the QRS complex of the ECG but is obscured by the ventricle depolarization.
Ventrical MuscleFibers
the repolarization of the atria is hidden by the QRS wave
It is a lengthening of the amount of time between depolarization of the ventricles of the heart, and the repolarization of the ventricles of the heart. The significance of this lies in the fact that the Q-T interval is a vulnerable time for the heart. Stimulation of the heart muscle during the relative refractory period (which is during the latter part of the Q-T interval) will cause a premature ventricular contraction, which may throw your heart into a dangerous dysrhythmia.