Arteries of the heart:

Not all arteries are listed here. For more information see here. This is a great site. Of particular note is the LAD, RCA, and Circumflex selections under the coronary angio dropdown menu.

I have included arteries directly referenced in My Story, or those arteries which have some pertinent relation to said referenced arteries.

Circumflex artery – (CX or LCX), also known as the left circumflex artery, or circumflex branch of the left coronary artery.

Obtuse marginal branches – branches off the the cirumflex artery. The first OM branch is called OM1, the second OM2, etc.

The first obtuse marginal or branch is the boundary between the proximal and distal portion of the Cx. Thus, the portion of the artery prior to the origin of the OM is known as the proximal Cx, while the segment just below the OM is the distal Cx.

Left Anterior Descending artery. The LAD also has branches known as septals and diagonals sverigeapotek.se.

The diagonal (Dx) branch comes off the LAD and runs diagonally across the anterior wall towards its outer or lateral portion. One or more Dx branches may exist. The first Dx branch is the boundary between the proximal and mid portion of the LAD. Thus, the portion of the artery prior to the origin of the Dx is known as the proximal LAD, while the segment just below the Dx is the mid LAD. The distal segment of the LAD is the terminal third of the artery.

From the LAD wikipedia link:

Septals originate from the LAD at 90 degrees to the surface of the heart, perforating and supplying the interventricular septum.

Diagonals run along the surface of the heart and supply the lateral wall of the left ventricle and the anterolateral papillary muscle.

Right Coronary Artery

The acute marginal (AM) branch is the boundary between the proximal and mid portion of the RCA. The segment just beyond the AM is the mid RCA.

The segment halfway between the AM and the origin of the PDA (posterior descending artery) is called the distal RCA.

Left Coronary Artery