Anterior Triangle of Neck (Animated Video)

#anteriortriangleofneck #necktriangles #headandneck
The anterior triangle of the neck is a large triangular space on each side of the neck, in front of sternocleidomastoid with its apex directed downwards and base directed upwards.
Boundaries
Anterior: Anterior median line of the neck.
Posterior: Anterior border of the sternocleidomastoid muscle.
Base: Lower border of the body of mandible and a line extending from the angle of mandible to the mastoid process.
Apex: Suprasternal notch at the meeting point between anterior border of sternocleidomastoid and anterior median line.
Roof: Investing layer of deep cervical fascia. The superficial fascia over the fascial roof contains platysma in the upper and anterior parts. The cervical branch of facial nerve and ascending and descending branches of transverse cervical cutaneous nerve.
Subdivisions
1. Submental triangle (half only).
2. Digastric (submandibular) triangle.
3. Carotid triangle.
4. Muscular triangle.
Digastric muscle: It has two bellies – posterior and anterior. The posterior belly arises from the digastric notch on the medial surface of the mastoid process, and runs downwards and forwards, towards the hyoid bone.
The anterior belly arises from digastric fossa on the base of the mandible near symphysis menti and runs downwards and backwards, towards the hyoid bone. Above the hyoid bone the two bellies are connected by an intermediate tendon, which is anchored to the hyoid bone by a fascial sling of investing layer of deep cervical fascia.
Omohyoid muscle: It consists of superior and inferior bellies joined at an angle by an intermediate tendon.
The inferior belly arises from upper border of scapula, near the suprascapular notch, it then passes behind the sternocleidomastoid and ends there in an intermediate tendon.
The superior belly begins at the intermediate tendon and is attached to the lower border of the hyoid bone. The intermediate tendon lies at the level of arch of cricoid cartilage and anchored to the clavicle by fascial sling derived from investing layer of deep cervical fascia.