Period 2/Mr. Mathieu
Author: Unknown, Source is Manchester University Published: May 13, 2014
URL: http://www.sciencedaily.com/releases/2014/05/140513113254.htm
Summary:
The University of Manchester has conducted a study in rodents that explains why athletes are more likely to need pacemakers in old age. Elder athletes can have arrhythmias, or heart rhythm disturbances. Their resting heart rate tends to be 30 beats per minute, while the average resting heart rate is 60 or more beats per minute. At first, scientists thought that the overuse of the vagal nerves, which lower heart rate, was a cause of the low heart rate in athletes. However, this study shows that the heart changes in training. In rodents, the heart’s pacemaker changes molecularly when exercising. Research shows that the amount of a pacemaker protein, HCN4, decreases in response to exercise and is the cause of lower heart rate. Researchers also say that by looking at the sinus node, which is a cardiac structure that generates heart rhythm, there can be a broader understanding of heart rhythm disturbances in athletes. However, frequent long-term exercise may have more advantageous effects that harmful.
Connection:
This connects to our curriculum on the systems in the human body. The pacemaker, or Sinoatrial node, is controlled by the autonomic nervous system. This system controls involuntary actions such as breathing and heartbeat. We learned how this system is divided into two parts, the sympathetic and parasympathetic division. The sympathetic raises the heartbeat, while the parasympathetic lowers that heartbeat. This is because sympathetic division increases the body’s activity, while the parasympathetic returns the body to its regular functions. This experiment also relates to our study on rats. Though this experiment used mice, rats have similar internal organs to humans, and since rats and mice are alike, it is possible that the scientists used a mouse for more accurate results.
The article says"'Although endurance exercise training can have harmful effects on the heart, it is more than outweighed by the beneficial effects.'" What are the beneficial effects and how exactly do they "outweigh" the negative?
ReplyDeleteWhat is the significance between the sinus node and a higher understanding of heart rhythm disturbances?
ReplyDeleteThe sinus node is the natural pacemaker of the heart, and if scientists delve deeper into understanding how it works, then they can find out what effects specifically change the sinus node for the better or the worse. If they understand how the sinus node can become inefficient, then they can apply that to other heart disturbances.
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