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The sinoatrial node generates action potentials at a faster pace than normal heart rate. Why does the heart beat more slowly than the SA node would dictate?
The vagus nerve is responsible for slowing down the heart rate, and is able to "override" the faster, natural pace of the sinoatrial node. When the vagus nerve is severed from the heart, the heart will pump at the pace of the SA node.
Note that innervation is not necessary for the heart to continue beating; it is self-sustaining, but can be affected by innervation from the vagus nerve.
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Which of the following structures is NOT part of the cardiac conducting system?
The chordae tendinae (tendinous chords or heart strings) are physical structures located in the heart lumen that connect the muscular wall of the heart to the tricuspid and mitral valves via papillary muscles.
The other answer options are examples of cell bundles and tissues that orchestrate the electrical conduction through the heart. Signals begin at the sinoatrial node and transition to the atrioventricular node. They then pass through the atrioventricular bundle (or bundle of His) to the purkinje fibers, which coordinate simultaneous ventricular contraction.
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What is the importance of the atrioventricular node's time delay upon receiving impulses from the sinoatrial node?
The sinoatrial node is responsible for initiating the contraction of the heart. Depolarization of the sinoatrial node coincides with atrial contraction. The depolarization travels very quickly to the atrioventricular node during this period. The atrioventricular node delays the spread of the impulse, preventing it from triggering ventricular contraction. This time delay allows the atria to fill the ventricles with blood before the impulse causes the ventricles to contract. Without this delay, an inadequate amount of blood would be pumped from the ventricles.
Compare your answer with the correct one above
The sinoatrial node generates action potentials at a faster pace than normal heart rate. Why does the heart beat more slowly than the SA node would dictate?
The vagus nerve is responsible for slowing down the heart rate, and is able to "override" the faster, natural pace of the sinoatrial node. When the vagus nerve is severed from the heart, the heart will pump at the pace of the SA node.
Note that innervation is not necessary for the heart to continue beating; it is self-sustaining, but can be affected by innervation from the vagus nerve.
Compare your answer with the correct one above
Which of the following structures is NOT part of the cardiac conducting system?
The chordae tendinae (tendinous chords or heart strings) are physical structures located in the heart lumen that connect the muscular wall of the heart to the tricuspid and mitral valves via papillary muscles.
The other answer options are examples of cell bundles and tissues that orchestrate the electrical conduction through the heart. Signals begin at the sinoatrial node and transition to the atrioventricular node. They then pass through the atrioventricular bundle (or bundle of His) to the purkinje fibers, which coordinate simultaneous ventricular contraction.
Compare your answer with the correct one above
What is the importance of the atrioventricular node's time delay upon receiving impulses from the sinoatrial node?
The sinoatrial node is responsible for initiating the contraction of the heart. Depolarization of the sinoatrial node coincides with atrial contraction. The depolarization travels very quickly to the atrioventricular node during this period. The atrioventricular node delays the spread of the impulse, preventing it from triggering ventricular contraction. This time delay allows the atria to fill the ventricles with blood before the impulse causes the ventricles to contract. Without this delay, an inadequate amount of blood would be pumped from the ventricles.
Compare your answer with the correct one above
The sinoatrial node generates action potentials at a faster pace than normal heart rate. Why does the heart beat more slowly than the SA node would dictate?
The vagus nerve is responsible for slowing down the heart rate, and is able to "override" the faster, natural pace of the sinoatrial node. When the vagus nerve is severed from the heart, the heart will pump at the pace of the SA node.
Note that innervation is not necessary for the heart to continue beating; it is self-sustaining, but can be affected by innervation from the vagus nerve.
Compare your answer with the correct one above
Which of the following structures is NOT part of the cardiac conducting system?
The chordae tendinae (tendinous chords or heart strings) are physical structures located in the heart lumen that connect the muscular wall of the heart to the tricuspid and mitral valves via papillary muscles.
The other answer options are examples of cell bundles and tissues that orchestrate the electrical conduction through the heart. Signals begin at the sinoatrial node and transition to the atrioventricular node. They then pass through the atrioventricular bundle (or bundle of His) to the purkinje fibers, which coordinate simultaneous ventricular contraction.
Compare your answer with the correct one above
What is the importance of the atrioventricular node's time delay upon receiving impulses from the sinoatrial node?
The sinoatrial node is responsible for initiating the contraction of the heart. Depolarization of the sinoatrial node coincides with atrial contraction. The depolarization travels very quickly to the atrioventricular node during this period. The atrioventricular node delays the spread of the impulse, preventing it from triggering ventricular contraction. This time delay allows the atria to fill the ventricles with blood before the impulse causes the ventricles to contract. Without this delay, an inadequate amount of blood would be pumped from the ventricles.
Compare your answer with the correct one above
The sinoatrial node generates action potentials at a faster pace than normal heart rate. Why does the heart beat more slowly than the SA node would dictate?
The vagus nerve is responsible for slowing down the heart rate, and is able to "override" the faster, natural pace of the sinoatrial node. When the vagus nerve is severed from the heart, the heart will pump at the pace of the SA node.
Note that innervation is not necessary for the heart to continue beating; it is self-sustaining, but can be affected by innervation from the vagus nerve.
Compare your answer with the correct one above
Which of the following structures is NOT part of the cardiac conducting system?
The chordae tendinae (tendinous chords or heart strings) are physical structures located in the heart lumen that connect the muscular wall of the heart to the tricuspid and mitral valves via papillary muscles.
The other answer options are examples of cell bundles and tissues that orchestrate the electrical conduction through the heart. Signals begin at the sinoatrial node and transition to the atrioventricular node. They then pass through the atrioventricular bundle (or bundle of His) to the purkinje fibers, which coordinate simultaneous ventricular contraction.
Compare your answer with the correct one above
What is the importance of the atrioventricular node's time delay upon receiving impulses from the sinoatrial node?
The sinoatrial node is responsible for initiating the contraction of the heart. Depolarization of the sinoatrial node coincides with atrial contraction. The depolarization travels very quickly to the atrioventricular node during this period. The atrioventricular node delays the spread of the impulse, preventing it from triggering ventricular contraction. This time delay allows the atria to fill the ventricles with blood before the impulse causes the ventricles to contract. Without this delay, an inadequate amount of blood would be pumped from the ventricles.
Compare your answer with the correct one above