External carotid artery

The external carotid artery (a.carotis externa) is one of the two terminal branches of the common carotid artery. It separates from the common carotid artery within the carotid triangle at the level of the upper edge of the thyroid cartilage. Initially, the external carotid artery is located medial to the internal carotid artery, and then lateral to it. The sternocleidomastoid muscle adjoins the initial part of the external carotid artery on the outside, and in the area of the carotid triangle - the superficial plate of the cervical fascia and the subcutaneous muscle of the neck. Located medially from the stylohyoid muscle and the posterior belly of the digastric muscle, the external carotid artery at the level of the neck of the mandible (in the thickness of the parotid gland) divides into its terminal branches - the superficial temporal and maxillary arteries. Along its path, the external carotid artery gives off a number of branches that depart from it in several directions. The anterior group of branches consists of the superior thyroid, lingual and facial arteries. The posterior group of branches includes the sternocleidomastoid, occipital and posterior auricular arteries; the ascending pharyngeal artery is directed medially.

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Anterior branches of the external carotid artery:

The superior thyroid artery (a.thyreoidea superior) branches off from the external carotid artery at its origin, at the level of the greater horn of the hyoid bone, is directed forward and downward, and at the upper pole of the thyroid lobe divides into the anterior and posterior glandular branches (rr.glandulares anterior et posterior). The anterior and posterior branches are distributed in the thyroid gland, anastomosing in the thickness of the gland with each other, as well as with the branches of the inferior thyroid artery. On the way to the thyroid gland, the following lateral branches branch off from the superior thyroid artery:

1. the superior laryngeal artery (a.laryngea superior) together with the nerve of the same name runs medially above the upper edge of the thyroid cartilage under the thyrohyoid muscle, pierces the thyrohyoid membrane and supplies blood to the muscles and mucous membrane of the larynx, the epiglottis;
2. the infrahyoid branch (r.infrahyoideus) goes to the hyoid bone and the muscles attached to this bone;
3. the sternocleidomastoid branch (r.sternocleidomastoideus) is inconstant, approaches the muscle of the same name from its inner side;
4. The cricothyroid branch (r.criocothyroideus) supplies the muscle of the same name and anastomoses with the same artery on the other side.

The lingual artery (a.lingualis) branches off from the external carotid artery slightly above the superior thyroid artery, at the level of the greater horn of the hyoid bone. It passes below the hyoglossus muscle, between this muscle (laterally) and the middle constrictor of the pharynx (medially), and passes into the region of the submandibular triangle. Then the artery enters the thickness of the tongue from below. On its way, the lingual artery gives off several branches:

1. the suprahyoideus branch (r. suprahyoideus) runs along the upper edge of the hyoid bone, supplies blood to this bone and the muscles adjacent to it;
2. the dorsal branches of the tongue (rr.dorsales linguae) depart from the lingual artery under the hyoglossus muscle and go upward;
3. The sublingual artery (a.sublingualis) goes forward to the hyoid bone above the mylohyoid muscle, lateral to the duct of the sublingual salivary gland, supplies the mucous membrane of the floor of the mouth and gums, the sublingual salivary gland, and anastomoses with the mental artery.
4. The deep artery of the tongue (a.profunda linguae) is large, is the terminal branch of the lingual artery, goes upward into the thickness of the tongue to its tip between the genioglossus muscle and the inferior longitudinal muscle (of the tongue).

The facial artery (a.facialis) departs from the external carotid artery at the level of the angle of the lower jaw, 3-5 mm above the lingual artery. In the area of the submandibular triangle, the facial artery is adjacent to the submandibular gland (or passes through it), giving it glandular branches (rr.glandulares), then bends over the edge of the lower jaw onto the face (in front of the masseter muscle) and goes up and forward, towards the corner of the mouth, and then to the area of the medial angle of the eye.

The following branches depart from the facial artery:

1. ascending palatine artery (a.palatina ascendens) from the initial part of the facial artery, goes up the lateral wall of the pharynx, penetrates between the styloglossus and styloglossus muscles (supplies them with blood). The terminal branches of the artery go to the palatine tonsil, the pharyngeal part of the auditory tube, the mucous membrane of the pharynx;
2. the tonsillar branch (r. tonsillaris) goes up the lateral wall of the pharynx to the palatine tonsil, the wall of the pharynx, and the root of the tongue;
3. The submental artery (a.submentalis) follows the outer surface of the mylohyoid muscle to the chin and muscles of the neck located above the hyoid bone.

On the face, in the area of the corner of the mouth, the following originate:

4. inferior labial artery (a.labialis inferior) and
5. superior labial artery (a.labialis superior).

Both arteries go into the thickness of the lips, anastomosing with similar arteries on the opposite side;

6. The angular artery (a.angularis) is the terminal branch of the facial artery, and goes to the medial angle of the eye. Here it anastomoses with the dorsal nasal artery - a branch of the ophthalmic artery (from the internal carotid artery system).

Posterior branches of the external carotid artery:

The occipital artery (a.occipitalis) departs from the external carotid artery almost at the same level as the facial artery, goes backwards, passes under the posterior belly of the digastric muscle, and then lies in the groove of the same name in the temporal bone. Between the sternocleidomastoid and trapezius muscles, it comes out onto the back of the head, where it branches in the skin of the back of the head into occipital branches (rr.occipitales), which anastomose with similar arteries on the opposite side, as well as with the muscular branches of the vertebral artery and the deep cervical artery (from the subclavian artery system).

The occipital artery gives rise to the following lateral branches:

1. sternocleidomastoid branches (rr.sternocleidomastoidei) to the muscle of the same name;
2. auricular branch (r.auricularis), anastomosing with the branches of the posterior auricular artery; goes to the auricle;
3. the mammillary branch (r.mastoideus) penetrates through the opening of the same name to the dura mater of the brain;
4. The descending branch (r.descendens) goes to the muscles of the back of the neck.

The posterior auricular artery (a.auricularis posterior) arises from the external carotid artery above the upper edge of the posterior belly of the digastric muscle and runs obliquely backward. The following branches arise from the posterior auricular artery:

1. the auricular branch (r.auricularis) runs along the back of the auricle, which it supplies with blood;
2. the occipital branch (r.occipitalis) goes backwards and upwards along the base of the mastoid process; supplies blood to the skin in the area of the mastoid process, auricle and occiput;
3. The stylomastoid artery (a.stylomastoidea) penetrates through the opening of the same name into the canal of the facial nerve of the temporal bone, where it gives off the posterior tympanic artery (a.tympanica posterior), which through the canal of the chorda tympani goes to the mucous membrane of the tympanic cavity, the cells of the mammillary process (mastoid branches), to the stapedius muscle (stapedius branch). The terminal branches of the stylomastoid artery reach the dura mater of the brain.

Medial branches of the external carotid artery:

The ascending pharyngeal artery (a.pharyngea ascendens) departs from the internal semicircle of the external carotid artery at its beginning, and rises upward to the lateral wall of the pharynx. The following branches depart from the ascending pharyngeal artery:

1. pharyngeal branches (rr.pharyngeales) go to the muscles of the pharynx, soft palate, palatine tonsil, auditory tube;
2. the posterior meningeal artery (a.meningea posterior) enters the cranial cavity through the jugular foramen;
3. The inferior tympanic artery (a.tympanica inferior) penetrates the tympanic cavity to its mucous membrane through the inferior opening of the tympanic canaliculus.

Terminal branches of the external carotid artery:

The superficial temporal artery (a.temporalis superficialis) is a continuation of the trunk of the external carotid artery, passes upward in front of the auricle (under the skin on the fascia of the temporal muscle) into the temporal region. The pulsation of this artery can be felt above the zygomatic arch in a living person. At the level of the supraorbital margin of the frontal bone, the superficial temporal artery divides into the frontal branch (r.frontalis) and the parietal branch (r.parietalis), which supply the epicranial muscle, the skin of the forehead and parieta and anastomose with the branches of the occipital artery. The superficial temporal artery gives off a number of branches:

1. branches of the parotid gland (rr.parotidei) depart under the zygomatic arch in the upper part of the salivary gland of the same name;
2. the transverse facial artery (a. transversa faciei) goes forward next to the excretory duct of the parotid gland (below the zygomatic arch) to the facial muscles and skin of the buccal and infraorbital regions;
3. the anterior auricular branches (rr.auriculares anteriores) go to the auricle and the external auditory canal, where they anastomose with the branches of the posterior auricular artery;
4. the zygomaticoorbital artery (a.zygomaticoorbitalis) extends above the zygomatic arch to the lateral angle of the orbit, supplies blood to the orbicularis oculi muscle;
5. The middle temporal artery (a.temporalis media) pierces the fascia of the temporal muscle, which this artery supplies with blood.

The maxillary artery (a.maxillaris) is also the terminal branch of the external carotid artery, but is larger than the superficial temporal artery. The initial part of the artery is covered on the lateral side by the branch of the mandible. The artery reaches (at the level of the lateral pterygoid muscle) to the infratemporal and further to the pterygopalatine fossa, where it splits into its terminal branches. According to the topography of the maxillary artery, three sections are distinguished in it: maxillary, pterygoid and pterygopalatine. The following arteries branch off from the maxillary artery within its maxillary section:

1. the deep auricular artery (a.auricularis profunda) goes to the temporomandibular joint, the external auditory canal and the eardrum;
2. the anterior tympanic artery (a.tympanica anterior) passes through the petrotympanic fissure of the temporal bone to the mucous membrane of the tympanic cavity;
3. the inferior alveolar artery (a.alveolaris inferior) is large, enters the canal of the mandible and gives off dental branches (rr.dentales) along its path. This artery leaves the canal through the mental foramen as the mental artery (a.mentalis), which branches in the facial muscles and in the skin of the chin. Before entering the canal, a thin mylohyoid branch (r.mylohyoideus) branches off from the inferior alveolar artery to the muscle of the same name and the anterior belly of the digastric muscle;
4. The middle meningeal artery (a.meningea media) is the largest of all the arteries that supply the dura mater of the brain. This artery enters the cranial cavity through the spinous opening of the greater wing of the sphenoid bone, where it gives off the superior tympanic artery (a.tympanica superior), which goes through the canal of the muscle that stretches the tympanic membrane to the mucous membrane of the tympanic cavity, as well as the frontal and parietal branches (rr.frontalis et parietalis) to the dura mater of the brain. Before entering the spinous opening, an additional branch (r.accessorius) departs from the middle meningeal artery, which initially, before entering the cranial cavity, supplies the pterygoid muscles and the auditory tube, and then, having passed through the oval opening into the skull, sends branches to the dura mater of the brain and to the trigeminal ganglion.

Within the pterygoid region, branches extend from the maxillary artery that supply the masticatory muscles:

1. the masseteric artery (a.masseterica) goes to the muscle of the same name;
2. the anterior and posterior deep temporal arteries (aa.temporales profundae anterior et posterior) go into the thickness of the temporal muscle;
3. pterygoid branches (rr.pterygoidei) go to the muscles of the same name;
4. the buccal artery (a.buccalis) goes to the buccal muscle and the mucous membrane of the cheek;
5. The posterior superior alveolar artery (a.alveolaris superior posterior) penetrates the maxillary sinus through the openings of the same name in the tuberosity of the maxilla and supplies its mucous membrane with blood, and its dental branches (rr.dentales) supply the teeth and gums of the upper jaw.

From the third - pterygopalatine section of the maxillary artery, three terminal branches depart:

1. The infraorbital artery (a.infraorbitalis) passes into the orbit through the inferior palpebral fissure, where it gives off branches to the inferior rectus and oblique muscles of the eye. Then, through the infraorbital foramen, this artery exits through the canal of the same name onto the face and supplies blood to the facial muscles located in the thickness of the upper lip, in the area of the nose and lower eyelid, and the skin covering them. Here, the infraorbital artery anastomoses with branches of the facial and superficial temporal arteries. In the infraorbital canal, the anterior superior alveolar arteries (aa.alveolares superiores anteriores) branch off from the infraorbital artery, giving off dental branches (rr.dentales) to the teeth of the upper jaw;
2. The descending palatine artery (a.palatina descendens), having initially given off the artery of the pterygoid canal (a.canalis pterygoidei) to the upper part of the pharynx and the auditory tube and having passed through the small palatine canal, supplies the hard and soft palate with blood by means of the large and small palatine arteries (aa.palatinae major et minores); gives off the sphenopalatine artery (a.sphenopalatma), which passes through the opening of the same name into the nasal cavity, and the lateral posterior nasal arteries (aa.nasales posteriores laterales) and the posterior septal branches (rr.septales posteriores) to the mucous membrane of the nose.