Carotid Triangle
The carotid triangle is a subdivision of the anterior triangle of the neck, containing the carotid sheath and its vital neurovascular contents. It is the site for carotid pulse assessment, carotid endarterectomy, and central venous catheterization.
Boundaries
superior
Posterior belly of digastric muscle
inferior
Superior belly of omohyoid muscle
anterior
Anterior midline of neck (when including muscular triangle)
posterior
Anterior border of sternocleidomastoid muscle
lateral
Sternocleidomastoid muscle
medial
Thyrohyoid and hyoglossus muscles
Contents
Carotid sheath contents
Other structures
Nerves
- • Vagus nerve (CN X)
- • Hypoglossal nerve (CN XII)
- • Ansa cervicalis
- • Superior laryngeal nerve
- • Glossopharyngeal nerve (CN IX)
Vessels
- • Common carotid artery
- • Internal carotid artery
- • External carotid artery
- • Superior thyroid artery
- • Lingual artery
- • Facial artery
- • Internal jugular vein
Muscles
- • Sternocleidomastoid
- • Digastric (posterior belly)
- • Omohyoid (superior belly)
- • Thyrohyoid
- • Sternohyoid
Clinical Relevance
- •Carotid pulse: Palpated against the transverse process of C6 (carotid tubercle), used in CPR and vital sign assessment
- •Carotid endarterectomy: Surgical removal of atherosclerotic plaque to prevent stroke
- •Internal jugular vein catheterization: Landmark-based or ultrasound-guided central line placement
- •Carotid sinus massage: Can terminate supraventricular tachycardia (baroreceptor reflex)
Study Tips
- ✓Carotid sheath: artery medial, vein lateral, nerve posterior between them
- ✓Internal carotid has NO branches in the neck (all branches are from external carotid)
- ✓Carotid body (chemoreceptor) and carotid sinus (baroreceptor) are at the bifurcation
- ✓Ansa cervicalis innervates the strap muscles (infrahyoid muscles)
Carotid Triangle FAQs
Common questions about this region
The internal carotid has no branches in the neck. The external carotid has multiple branches (superior thyroid, lingual, facial, etc.). At the bifurcation, the internal carotid is typically posterolateral and the external carotid is anteromedial.
The carotid body contains chemoreceptors that detect low oxygen, high CO2, and low pH in the blood. Stimulation increases respiratory rate and depth. The carotid sinus (separate structure) contains baroreceptors for blood pressure regulation.