QS Study

The carotid triangle is one of the natural geometrical formations of the neck. It is one of the paired triangles in the anterior triangle of the neck. The triangle is located anterolaterally on each side of the neck.

The boundary of the carotid triangle

(A) Superiorly: the Posterior belly of the digastric muscle & the stylohyoid. It is bounded by posterior belly of digastric complemented via stylohyoid.

(B) Antero inferiorly: the Superior belly of the omohyoid.

(C) Posteriorly: an Anterior border of the sternomastoid muscle. Anterior border of sternocleidomastoid.

(D) Roof: By Skin, superficial fascia & investing layer of deep cervical fascia. The superficial fascia consists of platysma, the cervical branch of facial nerve as well as transverse cervical nerve over the roof.

(E) Floor: By –

  • The thyrohyoid muscle.
  • The hyoglossus.
  • The middle & inferior constrictors of the pharynx.

carotid triangle 1

Fig: Boundary and Contents of Carotid Triangle

Contents of the carotid triangle – The main contents of the carotid triangle are the common carotid artery (which bifurcates within the carotid triangle into the external and internal carotid arteries), the internal jugular vein, and the hypoglossal and vagus nerves.

(A) Arteries:

  • The common carotid artery.
  • Internal carotid artery.
  • An external carotid artery with its branches.

(B) Veins:

  • The internal jugular vein.
  • The common facial vein.
  • Ascending pharyngeal vein.
  • The lingual vein.

(C) Nerves:

  • The vagus nerve.
  • The superior laryngeal nerve.
  • The spinal accessory nerve.
  • The hypoglossal nerve.
  • The Sympathetic chain.

(D) Carotid sheath with its contents: It’s a facial sheath which encloses internal jugular vein and internal and common carotid arteries. It is located posterior to the sternocleidomastoid muscle and is a part of the deep cervical fascia of the neck. Contents of the carotid sheath:

  • Common carotid artery
  • Internal jugular vein
  • Internal carotid artery
  • Vagus nerve.

(E) Lymph nodes:

  • The deep cervical lymph node.
  • Jugulodigastric lymph node.
  • Jugulo-omohyoid lymph node.
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