Question

nina studies an artificial heart model. the model has tubes that supply an electric current to the model. nina switches on the current that provides an impulse to the heart. she observes that the heart contracts and relaxes. compare this model with that of a human heart, and place the steps describing how blood flows through the human heart in order.
signal transferred to the ventricles
the atria contract
electrical signal travels toward the heart
the ventricles contract
signal by the nodes in the atrium
signal received by the atrioventricular node

Explanation:

Step1: Recall Cardiac Conduction Order

The normal cardiac conduction pathway starts with the electrical signal traveling toward the heart (from the sinoatrial node's initiation, but the step here is "electrical signal travels toward the heart"). Then, the signal is generated by the nodes in the atrium (sinoatrial node in atrium), so "signal by the nodes in the atrium". Next, the atria contract due to this signal, "the atria contract". Then the signal is received by the atrioventricular node, "signal received by the atrioventricular node". After that, the signal is transferred to the ventricles, "signal transferred to the ventricles". Finally, the ventricles contract, "the ventricles contract".

Step2: Order the Steps

1. electrical signal travels toward the heart
2. signal by the nodes in the atrium
3. the atria contract
4. signal received by the atrioventricular node
5. signal transferred to the ventricles
6. the ventricles contract

Answer:

1. electrical signal travels toward the heart
2. signal by the nodes in the atrium
3. the atria contract
4. signal received by the atrioventricular node
5. signal transferred to the ventricles
6. the ventricles contract