Question

what are the cells that make up the sinotral node, or pecamarker, located

Answer 1

I believe it is in the right atrium. So the heart.

Answer 2

Yes it is the right atrium. Here is a good source: http://www.medterms.com/script/main/art.asp?articlekey=5495

Answer 3

is it modified cardiac myocytes ????

Answer 4

They are technically Cardiac myocytes that are slightly modified. They are also known as pacemaker cells, found in the SA Node, within the right atrium of the heart. They set the natural rhythm of the heart.