[lee-usmle]

Have to learn and memorize these by heart

However the best way is to snap a mental image of all those muscles and borders

Here's an image modified from a creative commons media file found here

So the anterior triangle bounded by the sternocleidomastoid, the mid-line, and the mandible is further subdivided into four trianlges;

• The submandibular triangle (green) bounded by the diagastrics bellies and the mandible.
• The submental triangle also called suprahyoid (pink) bounded by the two anterior belly of the diagastric, the mid-line, and the chin above.
• The carotid triangle (light blue) bounded by the posterior belly of the diagastric, the superior belly of the omohyoid, and the sternocleidomastoid.
• The muscular triangle (orange) bounded by the superior belly of the omohyoid and the sternohyoid (the latter muscle is not seen in the image).

While the posterior triangle bounded by the sternocleidomastoid, the middle third of the clavicle, and the trapezius is further subdivided by the inferior belly of the omohyoid into two triangles; the occipital (red) and the subclavian (light blue).

Yet there's another triangle to worry about in USMLE!

Which is the sub-occipital triangle
bounded by the Obliquus Capitus Superior (OCS) and Obliquus Capitus Inferior (OCI) and the Rectus Capitus Posterior Major (RCPM) as illustrated in this image

Copyright notice: this image is modified from a copy of an image that fallen in the public domain.

This triangle gives access to the vertebral vein and artery before their entry into the foramen magnum

 

[khanar]

Thats cool

 

[indian]

it's really the sternocleidomastoid and the omohyoid that are making all those triangles !