BIOLOGICAL PACEMAKER-SA NODE

[dipjyoti]

Although all of the heart's cells possess the ability to generate the electrical impulses (or action potentials) that trigger cardiac contraction, the sinoatrial node is what normally initiates it, simply because it generates impulses slightly faster than the other areas with pacemaker potential. Because cardiac myocytes, like all muscle cells, have refractory periods following contraction during which additional contractions cannot be triggered, their pacemaker potential is overridden by the sinoatrial node.

Cells in the SA node will naturally discharge (create action potentials) at about 70-80 times/minute. Because the sinoatrial node is responsible for the rest of the heart's electrical activity, it is sometimes called the primary pacemaker.

If the SA node doesn't function, or the impulse generated in the SA node is blocked before it travels down the electrical conduction system, a group of cells further down the heart will become the heart's pacemaker. These cells form the atrioventricular node (AV node), which is an area between the atria and ventricles, within the atrial septum.

DIP JYOTI CHAKRABORTY.
FORMER NATIONAL CHILD SCIENTIST. MEMBER OF RAMSAR, GLAND;SWITZERLAND. MEMBER OF Epilepsy Foundation 8301 Professional Place Landover.
CONTACT:+919836435663

[MrMistery]

So?

[sdekivit]

previous year i studied the physiology of organsystems and knew already more then this (was 17 yrs old) --> mayb i should also be a national child scientist

[dipjyoti]

PLEASE STATE YOUR QUESTIONS CLEARLY. AND THIS IS NOT A PLACE TO IRONY SOME ONE.

The sinoatrial node (abbreviated SA node or SAN, also called the sinus node) is the impulse generating (pacemaker) tissue located in the right atrium of the heart. It is a group of cells positioned on the wall of the right atrium, near the entrance of the superior vena cava. These cells are modified cardiac myocytes. They possess some contractile filaments, though they do not contract.

[mith]

What's the point of this post? You're just posting some common definitions that anyone can find in a textbook...

[dipjyoti]

THE MAIN POINT IS THE COINAGE. I WROTE THIS ARTICLE FOR GIVING STRESS ON SA NODE, WHICH IS NATURALLY GIFTED.

HENCE ANY PERSON CAN ADD AN 'Artificial pacemaker' WHEN THE NATIVE HEART'S PACEMAKER IS NOT AS FAST AS NORMAL OR IF THERE ARE BLOCKS IN HEARTS ELECTRICAL CONDUCTION SYSTEM PREVENTING THE PROPAGATION OF ELECTRICAL IMPULSES FROM THE NATIVE PACEMAKER TO THE LOWER CHAMBERS OF HEART, KNOWN AS VENTRICLE.
THIS IS KNOWN AS EXTERNAL PACEMAKER. WHICH WAS FIRST DESIGNED AND BUILED BY CANADIAN ELECTRICAL ENGINEER JOHN HOPPS IN 1950.

[kjle]

i believe you're missing the point of this forum...this is not a place for people to just state general, common knowledge. Many of us already know this anyways, or like mith said, could easily find it in a textbook.

The point of this forum is to ask questions, about something you don't know, or just aren't sure of. There is a wealth of knowledge here at this site, but it's not just shared randomly, at least not in this section of the site. If you want to write an article, talk to admin/mods about how to in the appropriate section.

Kyle

[dipjyoti]

thanx, Kyle for giving me your suggestion and thanx to mr.mith also

[baikuza]

..... are you want to make article or post a question?? or want to know about the comment from other members??

if it is an article... i suggest you put it in article section..(ok.. i do not know what suggestion you got before...)(it is in the top of the page)

[mith]

Ok, thanks for the reply, your definitions are quite good, perhaps they might be better off in our dictionary(top right hand corner icon)? Either you can add to the existing one provided by wikipedia or you can create your own and add your name as one of the contributors.

Thanks!

[dipjyoti]

Welcome, Mith! I'm surfing your dictionary.