The left common carotid arises from the arch of the aorta and the right comes from the brachiocephalic trunk.
They travel through the neck in the carotid sheaths, medial to the internal jugular vein, and end at the cranial border of the thyroid cartilage (C4 vertebral level) by dividing into internal and external carotid arteries.
EXTERNAL CAROTID BRANCHES
6 branches and 2 terminal branches
3 from anterior – superior thyroid, lingual, facial
2 from posterior – occipital, posterior auricular
1 medial (deep) – ascending pharyngeal
Superior Thyroid Artery arises from the external carotid artery just below the level of the greater cornu of the hyoid bone
supplies the thyroid gland and anastomoses with the corresponding artery on the other side and with the inferior thyroid, a branch of the thyrocervical trunk. It also supplies neck muscles in the region and gives a superior laryngeal artery to the larynx through the thyrohyoid membrane.
Ascending Pharyngeal Artery the smallest branch of external carotid.
ascends vertically between the internal carotid and the side of the pharynx, to the under surface of the base of the skull, lying on the Longus capitis.
It is distributed to the pharynx, soft palate, auditory tube, palatine tonsil, part of the middle ear and the meninges. It anastomoses with the ascending cervical artery and other arteries supplying pharynx and middle ear.
Lingual Artery first runs obliquely upward and medialward to the greater cornu of the hyoid bone; it then curves downward and forward,
Crossed by the hypoglossal nerve, and passing beneath Digastric and Stylohyoid it runs horizontally forward, deep to Hyoglossus, and finally, ascending almost perpendicularly to the tongue
gives rise to the dorsal, deep and sublingual arteries that anastomose across the midline with corresponding vessels from the other side. The dorsal lingual artery also supplies the tonsil, soft palate and epiglottis.
Facial Artery courses deep to the intertendinous part of the digastric muscle, stylohyoid muscle and the submandibular gland
Submental branch given off in the submandibular fossa
superficial at the anterior border of the masseter on the border of the mandible and ends at the medial angle of the eye as the angular artery.
Deep to all facial muscles - Platysma, Risorius, and Zygomaticus, superficial to buccinator and may go through or above levator oris superioris
Anastomoses of the facial artery are very numerous not only with the vessel of the opposite side but also with the internal carotid and in the neck with the lingual and ascending pharyngeal arteries. In the face, it anastomoses with branches of the maxillary and superficial temporal arteries.
Branches in the neck - ascending palatineand tonsillar branches are the main supply to the palatine tonsil. Other branches supply the soft palate, and submandibular gland. Extensive anastomoses occur.
Branches in the face include superior and inferior labial and lateral nasal arteries that anastomose across the midline.
The angular artery anastomoses with dorsal nasal branches of the ophthalmic artery providing direct communication between the internal and external carotid arteries.
The anterior facial vein lies lateral to the artery, and takes a more direct course across the face, where it is separated from the artery by a considerable interval. In the neck it lies superficial to the artery.
Occipital Artery emerges inferior to digastric opposite to facial artery
gives off muscular branches and a descending branch which anastomoses with branches of the thyrocervical trunk (transverse cervical) and the costocervical trunk (deep cervical).These anastomoses assist in establishing collateral circulation after occlusion of the common carotid or subclavian arteries.
Supplies Trapezius, SCM, Digastric, Stylohyoid, Splenius, and Longus capitis
Hypoglossal nerve hooks around its descending branch.
terminal branches of the occipital artery are distributed to the back of the head: they are very tortuous, and lie between the integument and Occipitalis, anastomosing with the artery of the opposite side and with the posterior auricular and temporal arteries, and supplying the Occipitalis, the integument, and pericranium.
One of the terminal branches may give off a meningeal twig which passes through the mastoid foramen (inconstant)
Posterior Auricular Artery emerges above digastric and stylohyoid muscle, opposite the apex of the styloid process.
It ascends, under cover of the parotid gland, on the styloid process of the temporal bone, to the groove between the cartilage of the ear and the mastoid process, immediately above which it divides into its auricular and occipital branches.
Gives rise to the stylomastoid artery - enters the stylomastoid foramen and supplies the tympanic cavity, the tympanic antrum and mastoid cells, and the semicircular canals
The Occipital Branch passes backward, over the Sternocleidomastoideus, to the scalp above and behind the ear. It supplies the Occipitalis and the scalp and anastomoses with the occipital artery.
Superficial Temporal Artery supplies the parotid gland and temporal region of the face and scalp.
transverse facial - passes transversely across the side of the face, between the parotid duct and the lower border of the zygomatic arch
middle temporal - arises immediately above the zygomatic arch, and, perforating the temporal fascia, gives branches to the Temporalis, anastomosing with the deep temporal branches of the internal maxillary. It occasionally gives off a zygomaticoörbital branch, which runs along the upper border of the zygomatic arch, between the two layers of the temporal fascia, to the lateral angle of the orbit
frontal and parietal (terminal branches)
Maxillary Artery is divided into three parts based on its location relative to the lateral pterygoid muscle. The first part is lateral, the second part is either behind or in front of, and the third part is medial to the muscle.
Branches of the First part (5) pass through bony foramina.
Deep Auricular Artery - supplies external auditory meatus
Branches of the Third part (6) in pterygopalatine fossa - pass through bony foramina.
Posterior superior alveolar artery passes laterally through pterygomaxillary fissure to supply molars and premolars of the upper jaw and maxillary sinus.
Infraorbital artery passes through the inferior orbital fissure, infraorbital groove, canal and foramen. It gives off the:
Anterior superior alveolar artery to incisors and canine teeth of the upper jaw and adjacent gums.
Middle superior alveolar artery to premolars and gums.
Greater (descending) palatine artery descends through the Greater (descending) palatine canal to the greater palatine foramen. It supplies the hard palate, gums and lateral nasal wall. In the descending palatine canal it gives off branches:
Lesser palatine artery which arises in the Greater (descending) palatine canal as a branch of the greater palatine artery and descends through the lesser palatine foramen to supply the soft palate and tonsil. It anastomoses with the ascending palatine branch of the facial artery.
Posterior inferior lateral nasal artery a small branch to the lower lateral nasal wall.
Artery of the pterygoid canal goes through the canal and anastomoses with a branch of the internal carotid.
Pharyngeal artery goes through pharyngeal canal and is distributed to the upper pharynx.
Sphenopalatine artery enters the nasal cavity through the sphenopalatine foramen. It divides into:
Posterior superior septal branches - supply the nasal septum. Its nasopalatinebranch passes through the incisive canal where it anastomoses with the greater palatine artery in the mucosa on the hard palate.
Anterior facial vein joins with lingual vein and anterior division of retromandibular vein (posterior facial) to form the common facial vein – drains into internal jugular vein
Maxillary vein and superficial temporal vein forms the retromandibular vein
Retromandibular vein divides into anterior and posterior divisions
Posterior division joins with posterior auricular vein to form external jugular vein