Origin: Common carotid artery arises from the brachiocephalic trunk (right side) and the aortic arch (left side)
Course: Ascends in the neck in front of the prevertebral muscles, crossing the thyroid gland and the larynx
Relations:
- Anteriorly: Trachea, thyroid gland, and larynx
- Posteriorly: Prevertebral muscles
- Laterally: Sternohyoid and sternocleidomastoid muscles
Branches:
- External carotid artery
- Internal carotid artery
- Occipital artery (from the external carotid artery)
- Superior thyroid artery (from the external carotid artery)

Origin: Internal carotid artery arises from the common carotid artery
Parts:
- Cervical part: Ascends in the neck to the base of the skull
- Petrous part: Passes through the carotid canal in the petrous part of the temporal bone
- Cavernous part: Passes through the cavernous sinus
- Cerebral part: Passes through the cranium to the base of the brain
Course: Passes through the neck, base of the skull, and cranium to reach the brain
Relations:
- Anteriorly: Trigeminal ganglion, cavernous sinus, and pituitary gland
- Posteriorly: Meninges and the clivus
- Laterally: Carotid plexus and the cavernous sinus
Distribution:
- Supraclinoid part: Supplies the eye, optic nerve, and the adjacent structures
- Infraclinoid part: Supplies the anterior and middle cerebral arteries
Applied Anatomy:
- Internal carotid artery is often used as a landmark for locating the pituitary gland and the cavernous sinus
- It is also used as a landmark for identifying the base of the skull

Common carotid artery is an important landmark for identifying the base of the neck and the thyroid gland
Internal carotid artery is often used as a landmark for identifying the base of the skull and the cavernous sinus
The carotid bifurcation is an important landmark for identifying the common carotid artery and the internal carotid artery