Drag each tile to the correct box. 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.

The correct order is:

Electrical signal travels toward the heart .Signal received by the nodes in the atrium .The atria contract .Signal received by the atrioventricular node.Signal transferred to the ventricles .The ventricles contract .

Explanation:

The steps are:

Signal transferred to the ventricles .The atria contract .Electrical signal travels toward the heart .The ventricles contract .Signal received by the nodes in the atrium .Signal received by the atrioventricular node.

The question refers to the heart's physiological electrical conduction mechanism, which goes from the atrial node to the atrioventricular node, passes to the bundle of His and its branches, and then extends through the Purkinje fiber system, all so that coordinated events occur that allow blood flow within this organ.

The correct order of steps, linked to the activity of the heart and blood flow are:

Electrical signal travels towards the heart: the autonomic nervous system conducts the nerve impulse to the heart. Signal received by the nodes in the atrium: the atrial node, a structure that is located on the right atrium, receives the nerve impulse and is responsible for transmitting it to the ventricular atrial node. The atria contract: the contraction of this structure drives the blood to the ventricles, promoting the simultaneous opening of the atrioventricular valves. Signal received by the atrioventricular node: a node located in the interventricular septum is responsible for the distribution of the impulse to the His-Purkinje system. Signal transferred to the ventricles: the nerve signal passes to the His bundle, its branches and then the Purkinje fibers found in both ventricles. The ventricles contract: ventricular contraction promotes the emptying of your cavities, passing blood from the right ventricle to the lungs, and from the left ventricle to the general circulation. At this time the atrioventricular valves are closed and the sigmoid valves are opened, to allow anterograde blood flow.

Learn more:

Movement of oxygenated blood leaving the heart link