Internal Carotid Artery

1. Anatomy:
– The internal carotid artery (ICA) is a major branch of the common carotid artery.
– There are two ICAs, one on each side of the neck.
– They originate from the carotid bifurcation, ascend superiorly within the carotid sheath, and enter the skull through the external opening of the carotid canal.
– The ICA is divided into seven segments:
– Cervical (C1)
– Petrous (C2)
– Lacerum (C3)
– Cavernous (C4)
– Clinoid (C5)
– Ophthalmic (C6)
– Communicating segments (C7) (mnemonic: “Come, Please Let Children Consume Our Candy”)¹.

2. Branches:
– Along its course, the ICA gives rise to several branches:
– Caroticotympanic (C2)
– Vidian (C2)
– Meningeal (C4)
– Inferior Hypophyseal (C4)
– Superior Hypophyseal (C6)
– Ophthalmic (C6)
– Posterior Communicating (C7)
– Anterior Choroidal (C7) (mnemonic: “A VIP’S COMMA”).
– The terminal branches are the Anterior Cerebral and Middle Cerebral Arteries.

3. Function:
– The ICA supplies blood to several critical structures, with the brain being the most important.
– It ensures a constant and substantial blood supply to the brain, which weighs only 2% of the body but receives 15-20% of the daily cardiac output.
– Turbulent blood flow in a narrowed ICA can lead to symptoms like a bruit, transient ischemic attack (TIA), or stroke.

References:

(1) Internal carotid artery: Anatomy, segments and branches | Kenhub. https://www.kenhub.com/en/library/anatomy/internal-carotid-artery.
(2) Carotid artery disease – Harvard Health. https://www.health.harvard.edu/carotid-artery-disease-overview.
(3) Carotid artery disease – Symptoms and causes – Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/carotid-artery-disease/symptoms-causes/syc-20360519.
(4) Carotid Artery Disease – Clinical Features – TeachMeSurgery. https://teachmesurgery.com/vascular/arterial/carotid-artery-disease/.
(5) en.wikipedia.org. https://en.wikipedia.org/wiki/Internal_carotid_artery.