Anterior triangle Prepared by Muhammad Mustafa yousafzai Anterior

Anterior triangle Prepared by Muhammad Mustafa yousafzai

Anterior triangle • The anterior triangle is situated at the front of the neck. • It is bounded: • Superiorly – Inferior border of the mandible (jawbone) • Laterally – Medial border of the sternocleidomastoid • Medially – Imaginary sagittal line down midline of body

Boundries • The triangle is inverted with its apex inferior to its base which is under the chin. • Inferior boundary (apex) Jugular notch in the manubrium of the sturnum • Anterior boundary Midline of the neck from chin to the jugular notch •

• Posterior boundary The anterior margin of Sternocleidomastoideus • Superior boundary (base) The lower border of the body of the mandible, and a line extending from the angle of the mandible to the mastoid process

• The muscles in this part of the neck are divided as to where they lie in relation to the hyoid bone. • There are four suprahyoid muscles (stylohyoid, digastric, mylohyoid, and geniohyoid) and four infrahyoid muscles (omohyoid, sternohyoid, thyrohyoid, and sternothyroid)

content • Vasculature: • common carotid artery which bifurcates into external and internal carotid artery within the triangle. • Internal jugular vein drains the head and neck.

Nerves : • fascial 7 • Glossopharyngeal 9 • Vagus 10 • Accessory 11 • Hypoglossal 12

Subdivisions • 4 subdivisions • 1) carotid triangle • 2)submental triangle • 3)submandibular triangle • 4)muscular triangle

Carotid triangle • The carotid triangle of the neck has the following boundaries: • Superior: Posterior belly of the digastric muscle • Lateral: Medial border of the sternocleidomastoid muscle • Inferior: Superior belly of the omohyoid muscle

content • Common carotid artery • Internal jugular vein • Hypoglossal and vagus nerve

Carotid triangle

Clinical relevance • Superficial • Carotid sinus • Containing baroreceptors • Sinus nerve of hering branch of glossopharyngeal nerve to medulla.

Carotid sinus

Submental triangle • The submental triangle in the neck is situated underneath the chin. Its main content is the; • Submental lymph nodes, which filter lymph draining from the floor of the mouth and parts of the tongue.

Boundries • It is bounded: • Inferiorly – Hyoid bone. • Medially – Imaginary sagittal midline of the neck. • Laterally – Anterior belly of the digastric. • The base of the submental triangle is formed by the mylohyoid muscle, which runs from the mandible to the hyoid bone.

Submental triangle

Diagastric muscle

Submandibular triangle • The submandibular triangle is located underneath the body of the mandible. • Contents; • It contains the submandibular gland (salivary), and lymph nodes. • The facial artery and vein also pass through this area.

boundries • The boundaries of the submandibular triangle are: • Superiorly: Body of the mandible • Anteriorly: Anterior belly of the digastric muscle • Posteriorly: Posterior belly of the digastric muscle

Submandibular triangle

Muscular triangle • This anatomical area is situated more inferior than the triangular sub-divisions. It is a slightly dubious triangle, in reality having four boundaries. • The muscular triangle is also unique in containing no vessels of note. It does however contain some muscles – the infrahyoid muscles, the pharynx, and the thyroid, parathyroid glands.

Boundries • The boundaries of the muscular triangle are: • Superiorly: The hyoid bone • Medially: Imaginary midline of the neck • Supero-laterally: Superior belly of the omhyoid muscle • Infero-laterally: Inferior portion of the sternocleidomastoid muscle.