The electrical activity for the contraction of the heart is initiated by _______?

Answer

The heart generates its own electrical impulse for its own contraction.  This is what makes heart transplantation possible because you can take a heart out of a donor, and place it in a recipient.  The heart will still carry on beating.  Although it is not yet connected to the nervous system of the recipient.  The answer is the sinoatrial node which is an area of intrinsically, electrically, unstable specialized myocardial tissue located in the right atrium that generates the rhythm of the heart. Sinoatrial node or SA node is known as the pacemaker of the heart.

The atrioventricular node is the node between the atrium and ventricle that regulates the flow of electrical current from the top chambers of the heart, the atria, to the.ventricles.

The medulla oblongata is the lower part of the brain stem that contains a lot of the autonomic areas of the brain.  Sympathetic stimulation from here will speed up the heart.  Parasympathetic stimulation will slow down the heart.  

Individual myocytes will generate an electrical current but they will do so at a much slower rate than the sinoatrial node.  The rate of the heart is set by that which is depolarizing fastest.  

The motor cortex in the brain is in the frontal lobe.  That's responsible for the movement of all areas of the body.   The owner of the control of the will.  The heart is not under the control of the will.  It is under control by its own intrinsic electrical activity or be moderated by the activity of the medulla oblongata.  

To view the video from this lecture, click on the link below.  

  • Last Updated Feb 15, 2024
  • Views 1
  • Answered By Tamiko Kemp

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