GLOSSARY

The carotid arteries are the main arteries on both sides of the neck, supplying the brain, face, and neck; their name comes from the Greek karos, meaning “deep sleep”, because compressing them causes unconsciousness.

Anatomy

• Common carotid: on the right it arises from the brachiocephalic trunk, and on the left directly from the aortic arch.
• Bifurcation: at about the upper border of the thyroid cartilage (C3–C4 vertebrae), it divides into the internal carotid (brain and eye) and external carotid (face, scalp, and neck).
• Carotid sinus: a dilation at the start of the internal carotid containing baroreceptors (sensing blood pressure).
• Carotid body: chemoreceptors sensing blood oxygen, CO₂, and pH.