Occipital triangle

The occipital triangle is a subdivision of the lateral region of neck (posterior triangle) defined by the following boundaries: anteriorly by the posterior border of the sternocleidomastoid muscle, posteriorly by the anterior border of the trapezius muscle, and inferiorly by the inferior belly of the omohyoid muscle. The floor of the occipital triangle is formed by several muscles, including the splenius capitis, levator scapulae, and scalene muscles. The apex is at the point where the sternocleidomastoid and trapezius meet at the superior nuchal line.

This triangle contains important neurovascular structures, such as the spinal accessory nerve (cranial nerve XI), the lesser occipital nerve, and portions of the cervical plexus, as well as lymph nodes.