Final answer:
The incorrect statement is that the ventricles would contract but the atria would not due to the AV node passing signals to the Purkinje fibers, which is false as Purkinje fibers are responsible for ventricular contraction. In junctional dysrhythmias, abnormal AV node activity can lead to improper heart chamber contractions such as in a third-degree block.
Step-by-step explanation:
The incorrect statement regarding junctional dysrhythmias is: 'd. The ventricles would contract, but the atria would not, because the atrioventricular node passes the signal to the Purkinje fibers, which causes the atria to contract.' This statement is incorrect because it is the Purkinje fibers that allow the ventricles to contract, not the atria. The atrioventricular node (AV node) serves as a critical part of the cardiac conduction pathway by transmitting electrical impulses from the atria to the ventricles. Hence, if there's an issue at the AV node, such as in third-degree block, the atria may contract normally, but the ventricles will not necessarily follow in a coordinated manner.
In junctional dysrhythmias, the pacemaking impulse originates at or near the AV node, leading to altered timing or sequence of heart chamber contractions. Given your reference to third-degree block and the association with electrical conduction problems in the heart, this kind of arrhythmia would not typically allow normal atrial contraction followed by ventricular contraction.