a line drawn or visualized on the surface of the skin to represent the approximate location of some deeper-lying structure (such as an artery or vein)
Anatomical guide
a descriptive reference for locating arteries and veins by means of anatomical structures, which are known
Place of incision
the idealized location for an incision to be made through the subcutaneous layers of the skin, based largely on the liner and anatomical guides of the desired vessel being raised