Superficial Arteries and Veins of the Face and Scalp
The vasculature of the face and scalp can be a daunting and tedious topic to learn. The tiny vessels that supply individual muscles and skin are numerous. However, the anatomy student can gain assurance in the fact that they all originate from major vessels which lie deeper in the cervical region. The facial artery for instance is the fourth branch of the external carotid, and gives rise to numerous superficial arteries of the face. In order to learn the vessels, it is best to think of it as a network, all interconnecting and originating from the engine room of the vasculature, the heart.
This gives rise to the aorta, which in turn gives us the common, external and internal carotids. The internal carotid does not have any branches outside the skull (although rare exceptions have been reported), and the external carotid gives rise to the entire facial and scalp vasculature. A handy mnemonic is:
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This gives you the branches of the external carotid from bottom to top: Superior thyroid, Ascending pharyngeal, Lingual, Facial, Occipital, Posterior Auricular, Maxillary and Superficial temporal.
The Facial artery is the 4th branch of the external carotid and branches off in the carotid triangle. It is a very tortuous artery and this serves a functional purpose. That means the artery can accommodate head movements as well as pharyngeal expansion as in swallowing and facial movements of the cheeks, lips, and jaws. It arises above the ascending pharyngeal artery, and passes diagonally up from underneath the stylohyoid and digastric muscles. The vessel arches over the submandibular gland in a groove on its posterior surface. From there, it arches superiorly over the mandibular body in close association with the lower part of the masseter. The vessel then travels anteriorly and superiorly across the buccal region to reach the angle of the mouth, and then passes upwards along the side of the external nose, and terminates as the angular artery near the medial commissure of the eye.
The angular artery is essentially a terminal branch of the facial artery. The facial artery is the fourth branch of the external carotid artery. The branches of the vessel are closely attached to the angular head of the quadratus labii superioris (also known as levator labii superioris). The angular vein also accompanies the artery in this path.
In the buccal region, this artery distributes small branches that go on to anastomose with the infraorbital artery. The artery then goes on to supply the orbicularis oris, and the lacrimal sac, and ultimately terminates in an anastomosis with the nasal branch of the ophthalmic artery (the fourth branch of the external carotid).
The facial artery gives off a branch known as an inferior labial artery, which supplies the lower lip. It branches off close to the angle of the mouth, and it travels superiorly and anteriorly underneath the triangularis muscle (also knows as depressor anguli oris). It pierces the orbicularis oris and continuous its tortuous journey underneath the lower edge of the lower lip. It goes on to run beneath the mucous membrane and the aforementioned muscle. The vessel goes on to anastomose with the mental branch of the inferior alveolar artery. It then supplies the lower lip muscles and mucous membrane. The superior labial artery is a branch of the facial artery that supplies the upper lip, nasal septum and ala of the nose. That vessel is larger and more tortuous than its inferior counterpart. It follows a similar course to the inferior artery by passing between the orbicularis oris and mucous membrane, and journeys above the upper edge of the upper lip. The superior labial artery supplies the upper lip but also supplies the nose through a few branches. It also gives off a septal branch that can supply blood as far anteriorly as the nasal tip, and also gives off an alar branch that supplies the ala of the external nose.
Maxillary Artery Branches
The maxillary artery (the 7th branch of the external carotid) gives off an infraorbital artery. It also gives off the orbital branches and the anterior superior alveolar arteries. The orbital branches supply the rectus inferior, inferior oblique and the lacrimal sac. The anterior superior alveolar arteries descend through the anterior alveolar canal to supply to the upper incisor, canine teeth and the mucous membrane of the maxillary sinus.
Inferior alveolar artery is one of the 5 main branches from the maxillary artery. It supplies the tooth sockets of the mandible. That vessel becomes the incisor branch (to the incisor teeth), the mental branch which escapes via the mental foramen, the mylohyoid branch which is a branch of the inferior alveolar just before it enters the mandibular foramen. It supplies the mylohyoid muscle and runs in the mylohyoid groove.
External Carotid Artery
The posterior auricular artery is the 6th branch of the external carotid and is quite small. The landmarks that it originates superior to are the stylohyoid and digastric muscles. It generally emerges opposite to the tip of the styloid process. The artery passes superiorly deep to the parotid gland and passes with the styloid process. It travels further between the mastoid process and the cartilage of the external ear. The artery supplies the scalp behind the ear and the ear itself.
The occipital artery is the 5th branch of the external carotid artery. It most commonly arises opposite to the facial artery. The occipital artery passes underneath the posterior belly of the digastric muscle in order to access the occipital region. This vessel supplies the sternocleidomastoid muscles the posterior scalp and other deep neck and back muscles.
The submental artery is another branch of the facial artery (the largest cervical branch) which is given off just prior to the facial artery entering the submandibular gland. It runs forward upon the mylohyoid, below the mandible and beneath the digastric muscle. It supplies the surrounding muscles. The supraorbital artery is a branch of the ophthalmic artery that supplies the skin of the forehead, the scalp, the frontal sinus, upper eyelid, diploe and levator palpebrae superioris. The supratrochlear artery is the last branch of the ophthalmic artery. The terminal branches of the vessel anastomose with the supraorbital artery.
The middle temporal artery arises from the superficial temporal artery. It arises above the zygomatic arch and perforates the temporal fascia, gives branches to temporalis and anastomoses with the deep temporal branches of the internal maxillary artery. The superficial temporal artery is the 8th and final branch of the external carotid artery and is certainly a large artery of the head. It is commonly used by anaesthetists (anesthesiologists) who can readily access its pulse in the temporal region, above the zygomatic arch and above the tragus.
The transverse facial artery is a branch of the superficial temporal artery (the terminal branch of the external carotid). It supplies the parotid gland, parotid duct and masseter muscle. The zygomaticoorbital artery is an occasional branch of the middle temporal artery, it runs along the upper border of the zygomatic arch, between the two layers of the temporal fascia, and may arise from the superficial temporal artery also. The vessel supplies the orbicularis oculi and anastomoses with the lacrimal and palpebral braches of the ophthalmic artery.
Veins of the Face
The facial vein is a large vessel of the face and is much less tortuous than the artery of the same name. It lies posterior to the facial artery and begins from the lateral side of the nose. It drains the external palatine vein and will go on to join the retromandibular vein. This then forms the common facial vein. The inferior labial vein drains the lower lip and the superior labial vein drain the upper lip. The deep facial vein originates from the pterygoid venous plexus and is of considerable size. It communicates with the anterior facial vein.
The supraorbital vein begins its course on the forehead, and it communicates with the frontal branch of the superficial temporal vein. The vein passes inferiorly, superior to the frontalis muscle and commonly joins the frontal vein at the medial angle of the orbital socket, to form the angular vein. The supraorbital vein drains the forehead, eyebrow and upper eyelid.
The supratrochlear vein is also known as the frontal vein. It originates in the forehead in a venous plexus and combines with some frontal branches of the superficial temporal vein. All of these veins will converge onto a single trunk, close to the midline, which is usually parallel to the vein of the other side. The two trunks commonly combine via a transverse branch close to the root of the nose, referred to as the nasal arch. This arch usually receives some small branches of the nose. Rarely, the paired supratrochlear veins combine to form a single trunk, which drains the two angular veins at the nasal root.
The superficial temporal vein begins its course at the lateral aspect of the skull in a venous plexus with the supraorbital vein and the frontal vein. It combines with its partner vein on the opposing side, and also combines with the occipital and auricular vein. Numerous veins drain into this plexus, close to the zygomatic arch. This forms a trunk, which combines with the middle temporal vein, that exits from the temporalis muscle. This trunk will then go on to enter the parotid gland and unify with the internal maxillary vein and create the posterior facial vein.
The transverse facial vein begins its journey at the side of the skull in a venous plexus that also drains the supraorbital, posterior auricular, occipital, frontal and opposite transverse facial vein. This network also drains the parietal and frontal branches, which go on to unite superior to the zygomatic arch and eventually form the trunk of the combined veins. The middle temporal vein reveals itself from underneath the temporalis muscle and unites with it. The vein now traverses across the posterior root of the zygomatic arch, and subsequently enters the substance of the parotid gland. It will now meet with the internal maxillary vein to form the large posterior facial vein.
The angular vein is a small vein near the eye and is formed by the combination of the frontal and supraorbital veins. From this location it passes inferiorly, along the root of the nose until it reaches the orbital socket. At that point, it becomes the anterior facial vein. The vein receives blood from the nasal veins which run along the ala of the external nose, and goes on to combine with the superior ophthalmic vein via the nasofrontal vein. It therefore establishes a crucial anastomosis between the cavernous sinus and the anterior facial vein.
The posterior auricular vein begins its journey on the side of the head and also communicates with the occipital and superficial temporal veins via a venous plexus. From there it goes on to pass downwards posterior to the ear and combines with the posterior division of the posterior facial vein. It now forms the external jugular vein. It also drains some veins from the external ear and the stylomastoid vein.