The<unk>  can be used as a landmark for several nerve branches, as well as an approximate marker for the umbilicus (belly button). It is also used as the divider between the lower (left and right) and upper (left and right) quadrants of the abdomen (where the vertical midline divides left from right). It is also the level where the abdominal aorta bifurcates into the left and right common iliac artery and just superior to the union of the common iliac veins. It can help in the identification of the level of L4/L5 where a lumbar puncture can be done.
Supracristal plane
Radial plane
Presacral space
Mid-inguinal point
Muscular triangle
Coronal plane
Sagittal plane
Subclavian triangle