Overview
- At its commencement, lies against side wall of Pharynx anteromedial to Internal Carotid Artery
- Ascends in front of Internal Carotid deep to the Posterior Belly of Digastric and Stylohyoid
- Pierces the Parotid Fascia to enter the Parotid Gland
- Divides within the gland behind the neck of the Mandible into Maxillary Artery and Superficial Temporal Artery
- As it lies within the Parotid Gland, it is separated from the Internal Carotid by the deep part of the Gland, its fascia, Styloid Process and it’s continuation the Stylohyoid Ligament, Styloglossus and the ‘Pharyngeal Structures’
- Stylopharyngeus muscle
- Glossopharyngeal Nerve
- Pharyngeal Branch of the Vagus Nerve
- Facial Vein crosses artery with Hypoglossal Nerve lying between
- Lies mostly in the anterior border of SCM
Branches of External Carotid Artery
- Before dividing into 2 terminal branches (Superficial Temporal Arteryand Maxillary Artery), it gives off 6 branches – 3 from in front, 2 from behind, and one from its deep (medial) aspect
- Three from in Front:
- Superior Thyroid Artery
- Lingual Artery
- Facial Artery
- Two from Behind:
- Occipital Artery
- Posterior Auricular Artery
- One from deep:
- Ascending Pharyngeal Artery
- Some Anatomists Like Freaking others prefer bdSM
Details of External Carotid Artery Branches
Superior Thyroid Artery
- Arises at commencement of External Carotid
- Runs almost vertically downwards, with the vein, to the upper pole of Thyroid
- Runs with the External Laryngeal Nerve close behind it
- Before reaching Thyroid, it gives off Infrahyoid, SCM, Superior Laryngeal and Cricothyroid branches
- Superior Laryngeal Artery pierces the Thyrohyoid Membrane with the Internal Laryngeal Nerve
- Cricothyroid Artery crosses the upper part of the Cricothyroid membrane to anastomose with the contralateral artery
Lingual Artery
- Arises above the Superior Thyroid Artery from the External Carotid Artery
- Forms a short loop and then passes forwards along the upper border of the Greater Horn, deep to Hyoglossus
- Accompanied by the Lingual Vein
- Loop of artery crossed laterally by Hypoglossal Nerve and its companion vein – latter opening into the Facial Vein
Facial Artery
- Arises above the Lingual Artery from the External Carotid Artery
- Runs upwards on the Superior Constrictor
- Deep to Digastric and Stylohyoid Muscles
- Then deep to Submandibular Gland
- Grooves posterosuperior part of the Gland
- As it lies on the Superior Constrictor, it gives off Tonsillar and Ascending Palatine branches to the Tonsil and Soft Palate
- Makes an S-bend curling over the Submandibular Gland
- Crosses the inferior border of the Mandible anterior to the Masseter
- Gives off Submental Artery before it passes to the face
Occipital Artery
- Arises from the back at a level with the Facial Arteryfrom the External Carotid Artery
- Courses backwards deep to lower part of Posterior Belly of Digastric
- Grooves the base of the skull at the Occipitomastoid suture, deep to digastric notch on the Mastoid Process
- Passes through apex of Posterior Triangle to supply back of Scalp
- Gives off 2 branches to SCM
- At its origin, the artery crosses lateral to the Hypoglossal Nerve – which hooks around it from behind
- Nerve held down here by lower SCM branch of the Artery
Posterior Auricular Artery
- Arises above level of Digastric muscle – often within Parotid Gland
- Runs superficial to Styloid Process above the Digastric Posterior Belly
- Crosses surface of Mastoid process to supply Scalp
- Auricular branches supply pinna
- Stylomastoid branch enters the Stylomastoid Foramen and supplies Facial Nerve
Ascending Pharyngeal Artery
- Arises just above the commencement of the External Carotid
- Runs along side wall of Pharynx in front of Prevertebral Fascia
- Deep to Internal Carotid Artery
- Supplies pharyngeal wall, Soft Palate, sends meningeal branches through nearby foramina in the base of skull (Foramen Lacerum, Jugular Foramen, Hypoglossal Canal)
