Common Carotid Artery

GROSS ANATOMY:
ORIGIN
  • Although the left and right common carotid arteries follow the same course through the neck, their origin differs.
  • On the left, the common carotid arises directly from the aortic arch begins in thorax in front of trachea.
  • On the right, the origin is from the brachiocephaic trunk begins behind right sternoclavicular joint
  • The left common carotid artery can be thought of as having two distinct parts: thoracic and cervical. Since the right common carotid arises caudally, it only really has a cervical portion.
  • In the thoracic section, the left common carotid travels upwards through the superior mediastinum to the level of the left sternoclavicular joint where it is continuous with the cervical portion.
  • The cervical section of both common carotids follows a similar course lies in carotid sheath.
  • Lies in front of transverse process of lower 4 cervical vertebrae
  • Each vessel passes obliquely upwards from behind the sternoclavicular joint to the level of the upper border of the thyroid cartilage.
  • In the lower neck, the two common carotid arteries are separated from each other by the trachea.
  • However, as the carotids rise in the neck, they diverge come to be separated by the thyroid gland, the larynx and pharynx.
  • Each common carotid is contained within the carotid sheath which is derived from all 3 layers of the deep cervical fascia.
  • In addition to containing the common carotid artery, the sheath also comprises the internal jugular vein and vagus nerve: the vein lies lateral to the artery, with the nerve in between the two.
  • At the level of the fourth cervical vertebra,at the level of upper thyroid the vessel bifurcates into the external and internal carotids.

BRANCHES:

COMMON CAROTID ARTERY
Carotid Bifurcation(behind it lies carotid body)
↓(Lateral to external carotid),↓
Internal Carotid Artery External Carotid Artery
↓ (Branches) ↓(Branches)
Cervical Part:no branches in neck) Anterior
Petrous Part → SUPERIOR THYROID
→ CARDIO TYMPANIC → LINGUAL
→ PTERYGOID BRANCH → FACIAL
Cavernous Part Posterior
→ BRANCHES TO TRIGEMINAL GANGLION → OCCIPITAL
→ BRANCHES TO HYPOPHYSIS CEREBRI → POSTERIOR AURICULAR
Cerebral Part Medial
→ OPTHALMIC → ASCENDING PHARYNGEAL
→ ANTERIOR CEREBRAL Terminal
→ MEDIAL CEREBRAL → MAXILLARY
→ POSTERIOR CEREBRAL → SUPERFICIAL TEMPORAL
→ ANTERIOR CHOROIDAL
APPLIED ANATOMY:
  • Common carotid artery can be felt at the lower part of the medial border of sternocleidomastoid.
  • Common carotid artery is palpated at upper border of cricoid cartilage
  • The commonest variation in the arteries arising from the arch of aorta is Left common carotid artery arising from brachiocephalic trunk
  • Hanging causes large amount of injury to common carotid artery
  • Dye is injected in common carotid in cerebral angiography
 Exam Question 
  • Common carotid artery ends at the level of upper border of the thyroid cartilage by dividing into external & internal carotid arteries 
  •  The left common carotid arises directly from the aortic arch
  •  Internal carotid artery at the bifurcation from the common carotid is Lateral to the external carotid 
  •  Common carotid artery can be felt at the lower part of the medial border of sternocleidomastoid 
  • Common carotid artery is palpated at upper border of cricoid cartilage 
  • The commonest variation in the arteries arising from the arch of aorta is Left common carotid artery arising from brachiocephalic trunk 
  • Hanging causes large amount of injury to common carotid artery
  •  Dye is injected in common carotid in cerebral angiography 
  •  Right common carotid artery arises from brachiocephalic trunk
Don't Forget to Solve all the previous Year Question asked on Common Carotid Artery