AN32.1-2 | Anterior Triangle — Glossary

Triangular space bounded by the midline of the neck, anterior border of SCM, and lower border of the mandible

Most surgically important sub-triangle containing the carotid bifurcation, IJV, and cranial nerves IX, X, XI, XII

Sub-triangle also called the submandibular triangle, containing the submandibular gland, facial vessels, and CN XII

Only midline sub-triangle, containing submental lymph nodes that drain the tip of tongue, floor of mouth, and central lower lip

Inferomedial sub-triangle containing the infrahyoid strap muscles, thyroid gland, trachea, and oesophagus

Division of the common carotid artery into internal and external carotid arteries at the level of C4 (upper border of thyroid cartilage)

Chemoreceptor at the carotid bifurcation that detects changes in blood oxygen, carbon dioxide, and pH

Nerve loop on the anterior surface of the carotid sheath (C1-C3) supplying the infrahyoid strap muscles

Mixed salivary gland in the digastric triangle that wraps around the posterior border of mylohyoid; Wharton's duct opens beside the frenulum of the tongue

Four muscles below the hyoid (sternohyoid, sternothyroid, thyrohyoid, omohyoid) that depress the hyoid and larynx during swallowing

Two-bellied muscle with anterior belly (CN V3) and posterior belly (CN VII) joined by an intermediate tendon attached to the hyoid

Two-bellied muscle with superior and inferior bellies joined by an intermediate tendon; the superior belly subdivides the anterior triangle

Midline neck swelling arising from remnants of the thyroglossal duct; moves on swallowing and tongue protrusion

Surgical excision of a thyroglossal cyst including the central portion of the hyoid bone and the tract up to the foramen caecum to prevent recurrence

Pit at the junction of the anterior two-thirds and posterior one-third of the tongue marking the origin of the thyroglossal duct

Surgical removal of atheromatous plaque from the carotid bifurcation requiring detailed knowledge of carotid triangle anatomy

Pure motor nerve supplying all tongue muscles except palatoglossus; crosses over the ECA and ICA in the carotid triangle

Branch of CN X dividing into internal (sensory to larynx above vocal cords) and external (motor to cricothyroid) branches

Thin subcutaneous muscle of the neck in the superficial fascia that forms part of the roof of the anterior triangle

Outermost deep cervical fascia that splits to enclose SCM and trapezius, forming the roof of both anterior and posterior triangles

Branch of ECA that grooves the submandibular gland posteriorly and crosses the mandible at the anterior border of masseter to supply the face

Enlargement of cervical lymph nodes; tuberculous lymphadenitis is the commonest cause of neck swelling in India