Vascular system in the head and neck

Vascular system in the Head and Neck

Diala M. Alghalayini

Arteries in the neck• 2 major arteries: subclavian artery

and common carotid artery.• The subclavian artery gives rise to the

vertebral arteries.• Origin of left and right common

carotid and subclavian arteries is different.

• Left subclavian and left common carotid arise from the aortic arch

• While on the right side the brachiocephalic divides into common carotid and subclavian arteries after a short course.

Common Carotid Artery

CAROTID SHEATH

• Contents of the carotid sheath:– Common carotid artery– Internal jugular vein– Vagus nerve

• Each common carotid artery ascends through the neck alongside these structures bound together by the carotid sheath.

Common carotid artery

• Runs upward through the neck under the cover of the anterior border of the sternocleidomastoid.

• Divides into internal carotid artery and external carotid artery.

• Level of bifurcation is usually about the level of the upper border of the thyroid cartilage or hyoid bone.

• Internal carotid artery continues upwards within the carotid sheath.

• External carotid artery leaves the sheath and becomes external to it.

Relations of the common carotid artery

• Anterolaterally: skin, fascia, sternocleidomastoid muscle, sternohyoid, superior belly of omohyoid.

• Posteriorly: transverse processes of the lower four cervical vertebrae, prevertebral muscles, sympathetic trunk, vertebral vessel in the lower part of the neck.

• Medially: larynx, pharynx, trachea, esophegus, thyroid gland.

• Laterally: internal jugular vein, vagus nerve posterolaterally.

Relations of the common carotid artery

What is the carotid sinus•The carotid sinus is a dilatation on the common carotid artery at its bifurcation, then continues a little way up the internal carotid branch.•It contains barorecptors monitoring blood pressure•It is innervated by the carotid branch of the glossopharyngeal nerve

Carotid body

• It is situated behind the sinus or between the internal and external carotid arteries only a few millimeters in width.

• It contains chemoreceptors responding to oxygen and carbon dioxide levels in blood.

• It is innervated by the glossopharyngeal nerve

External carotid artery

• Begins at the level of the upper border of the thyroid cartilage.

• Ascends through the upper part of the neck supplying multiple branches to adjacent structures.

• It passes deep to the digastric and stylohyoid muscles then pierces the parotid fascia to enter the gland at about the level of the angle of the mandible where it ends by dividing into maxillary and superficial temporal branches.

• External carotid artery has 8 branches.

Relations of the external carotid artery

• Anterolaterally: anterior border of the sternocleidomastoid muscle, above this level the artery is superficial, covered by skin and fascia. Hypoglossal nerve crosses lateral to it. Posterior belly of digastric, and stylohyoid muscles (lateral). Internal jugular vein lies lateral to the artery then posterior to it.

Relations of the external carotid artery

• Medially: wall of pharynx, internal carotid artery, stylopharyngeus muscle and glossopharyngeal nerve.

External carotid artery

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• S: superior thyroid artery• A: ascending pharyngeal artery• L: lingual artery• F: facial artery• O: occipital artery• P: posterior auricular artery• M: maxillary artery• S: superficial temporal artery

Branches of the external carotid artery• Superior thyroid artery– Branch off almost immediately after

the bifurcation. It arises from the front of the external carotid just below the level of the hyoid bone.

– Descend and spread out to supply anterosuperior aspects of thyroid gland and adjacent muscles

– Has small penetrating branches the supply the larynx

– It gives off a superior laryngeal branch which accompanies the internal laryngeal nerve to the upper part of the larynx and adjacent part of the pharynx.

Branches of the external carotid artery

• Ascending pharyngeal arteries– Arise at about the same level as the

superior thyroid arteries, hidden on the medial aspect of the external carotid artery.

– Ascend on the side of the pharynx and supply it.

– At the base of the skull it gives off a number of small meningeal branches which enter the cranial cavity through the foramen lacerum and the jugular foramen.

– Contributes to the blood supply of the palatine tonsils

Branches of the external carotid artery• Lingual artery– Lingual and facial artery may arise separately from a short

common stem.– It leaves the anterior surface of the external carotid opposite

the hyoid bone. It runs forwards, making a characteristic upward loop, and then passes deep to the hyoglossus muscle to enter the floor of the mouth.

– Lingual artery passes deep to the mandible and cross the floor of the mouth to ascend into the tongue.

– It supplies the tongue and floor of the mouth.

Branches of the external carotid artery• facial artery– arises from the front of the external carotid artery a short

distance above the lingual artery. It runs upwards in a deep groove on the posterior surface of the submandibular gland and deep to the ramus of the mandible, curves over the superior aspect of the gland and then runs downwards and forwards between the lateral surface of the gland and the medial surface of the mandible. It hooks around the inferior border of the mandible at the anterior edge of masseter to enter the face.

– In the neck it gives off an ascending palatine branch which ascends alongside the pharynx to supply the soft palate, a tonsillar branch to the palatine tonsil and a submental branch which runs forwards on the superficial surface of the mylohyoid muscle to supply nearby muscles and skin.

Branches of the Facial artery

• cervical – Ascending palatine artery– Tonsillar branch– Submental artery– Glandular branches

• facial – Inferior labial artery– Superior labial artery– Lateral nasal branch to nasalis muscle– Angular artery - the terminal branch


• occipital artery– leaves the back of the external

carotid above the level of the hyoid bone. Runs medial to the digastric muscle and then in the occipital groove on the mastoid part of the temporal bone. On leaving the occipital groove it turns superficially to supply the posterior part of the scalp.

• posterior auricular artery – arises from the posterior part of the external carotid above

the digastric muscle. It ascends, between the parotid gland and styloid process

– supplies the auricle and scalp behind the ear.– at the stylomastoid foramen it gives off its stylomastoid

branch which runs through the foramen to supply the tympanic cavity.


• Superficial temporal artery– begins in the parotid gland immediately behind the neck of the

mandible, runs upwards across the posterior root of the zygomatic process of the temporal bone where it can be palpated in front of the auricle and then divides into anterior and posterior branches

– crossed by the upper branches of the facial nerve within the parotid gland and accompanied in the scalp by the corresponding veins and the auriculotemporal nerve.

– It supplies the scalp.



• Superficial temporal artery• Before dividing into its terminal branches the artery gives off

several branches. – the transverse facial artery : arises in the parotid gland and runs

forwards across the masseter muscle supplying the gland and its duct and the masseter muscle

– branches to the external ear– zygomatic artery which runs along the upper border of the zygomatic

arch towards the lateral angle of the eye supplying adjacent muscles– middle temporal artery which arises above the zygomatic arch, pierces

the temporal fascia and supplies, together with the deep temporal branch of the maxillary artery, the temporalis muscle.

– The terminal anterior and posterior branches supply the frontal and parietal regions of the scalp respectively

Maxillary Artery

• One of the terminal branches of the external carotid artery, it begins in the parotid gland posterior to the neck of the mandible.

• enters the infratemporal fossa by curving forwards deep to the mandibular neck. then crosses the lower head of the lateral pterygoid, usually lying superficial but occasionally deep to that belly, to enter the pterygopalatine fossa through the pterygomaxillary fissure.

Branches of the first part• It is posterior to lateral pterygoid muscle

(five branches)• Five branches, each of which enters a

bony foramen:– The deep auricular artery supplies the

lining of the external acoustic meatus – the anterior tympanic artery passes

through the petrotympanic fissure to supply part of the lining of the tympanic cavity.

– The middle meningeal artery provides the principal source of blood to the meninges. It ascends deep to lateral pterygoid, passes between the two roots of the auriculotemporal nerve, enters the cranial cavity through the foramen spinosum.

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– The accessory meningeal artery ascends in front of the middle meningeal artery to enter the skull through the foramen ovale. It gives branches to neighbouring muscles before entering the foramen.

– The inferior alveolar artery runs downwards posterior, and in close relationship, to the nerve of the same name. Before entering the mandibular foramen it gives off its mylohyoid branch which pierces the sphenomandibular ligament and passes to the superficial aspect of the mylohyoid muscle in company with the corresponding nerve. The inferior alveolar artery runs forwards in the mandibular canal to supply the bone of the lower jaw, the inferior dentition and, through its mental branch, the lower lip

Branches of the first part

Branches of the second part• within lateral pterygoid muscle (five

branches)o The second part of the artery gives

two deep temporal arteries branches to the temporalis muscle, anterior temporal, posterior temporaL

o pterygoid branches to the pterygoid muscles

o the masseteric branch which passes to the masseter muscle

o the buccal branch which accompanies the buccal nerve to supply the structures of the cheek.

o A small lingual branch accompanies the lingual nerve

Branches of the third part• that part of the vessel within the

pterygopalatine fossa) gives off – posterior superior alveolar artery – infraorbital artery (enters infrerior

orbital fissure) gives anterior superior alveolar artery, and middle superior alveolar artery.

– artery of the pterygoid canal – pharyngeal artery – greater (descending) palatine

artery (enters greater palatine foramen)

– sphenopalatine artery terminal branch (enters sphenopalatine foramen)

Maxillary artery Branches

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Maxillary Artery Branches• D: deep auricular artery• A: anterior tympanic artery• M: middle meningeal artery• I: inferior alveolar artery• A: accessory meningeal artery• M: masseteric artery• P: pterygoid artery• D: deep temporal artery• B: buccinator artery• S: sphenopalatine artery• D: descending palatine artery• I: infraorbital artery• P: posterior superior alveolar artery• M: middle superior alveolar artery• P: pharyngeal artery• A: anterior superior alveolar artery• A: artery of the pterygoid canal

Internal carotid artery• The internal carotid artery continues upwards within the

carotid sheath from its origin at the bifurcation of the common carotid.

• It lies at first superficial to the external carotid artery but as it ascends it comes to occupy a position behind and deep to it.

• At the base of the skull it enters the carotid canal and gains access to the cranial cavity.

• The internal carotid artery has no branches within the neck. Its branches are in the cranial cavity.

• The artery carries with it a network of nerves (the internal carotid plexus) from the superior cervical ganglion.

Internal carotid artery

Internal carotid artery

• In the cranial cavity the artery passes upward and forward in the cavernous sinus without communicating with it.

• Passes medial to the anterior clinoid process. It inclines backward lateral to the optic chiasma.

• Terminates by dividing into anterior and middle cerebral artery.

Relations of the Internal carotid artery

• Anterolaterally: – Below the digastric: skin, fascia, anterior border of

the sternocleidomastoid, and hypoglossal nerve.– Above the digastric: stylohyoid muscle,

stylopharyngeus muscle, glossopharygeal nerve, pharyngeal branch of vagus, parotid gland, external carotid artery.

• Posteriorly: sympathetic trunk, longus capitis muscle, transverse processes of upper 3 cervical vertebrae.

• Medially: pharyngeal wall, superior laryngeal nerve.

• Laterally: internal jugular vein, vagus nerve.

Relations of the Internal carotid artery

Branches of the internal carotid artery

• There are no branches in the neck, branches are given off in the skull:

• Ophthalmic artery: arises as the internal carotid artery emerges from the cavernous sinus. Passes through the optic canal and gives off the central artery into the eyeball. The central artery is the only artery to supply the retina.

• Posterior communicating artery: runs backwards and joins posterior cerebral artery.

• Anterior cerebral artery: terminal branch of the internal carotid, passes forward between the cerebral hemispheres, winds around the corpus callosum of the brain. Supplies the medial and superolateral surfaces of the cerebral hemispheres. Joins the artery of the opposite side by the anterior communicating atery.


• Middle cerebral artery: largest terminal branch of the internal carotid artery, runs laterally in the lateral cerebral sulcus of the brain. Supplies the entire lateral surface of the cerebral hemisphere except a narrow strip along the superolateral margin (anterior cerebral artery), the occipital pole and inferolateral surface of the hemisphere (posterior cerebral artery)

• Middle cerebral artery supplies all motor area of the cerebral cortex except leg area.


Circle of Willis• It lies in the subarachnoid space at the

base of the brain.• The circulus is formed by the anastomosis

between the branches of the 2 internal carotid arteries and the 2 vertebral arteries.

• The communicating vessels are small and are usually inadequate to maintain sufficient circulation to the brain if one or other of the internal carotid arteries is suddenly blocked.

• They are capable of expanding if the blockage occurs more slowly so that an adequate cerebral blood supply may be maintained.

• Cortical and central branches arise from the circle to supply the brain.

Vertebral artery • The vertebral artery is a branch of the subclavian artery. It ascends

through the neck, in the foramina in the transverse processes of the upper six cervical vertebrae

• around the lateral mass of the atlas and enters the cranial cavity through the foramen magnum. Here it pierces the dura and arachnoid mater and runs in the subarachnoid space upwards and medially in front of the rootlets of the hypoglossal nerve to join the artery of the opposite side at the lower border of the pons. The artery so formed is the basilar. At upper border of the pons it divides into right and left posterior cerebral arteries

• Within the cranial cavity the vertebral artery gives rise to spinal branches which pass downwards to the spinal canal, a posterior inferior cerebellar branch to the cerebellum and medullary branches to the medulla oblongata. Arising from either side of the basilar artery are pontine branches, a labyrinthine branch to the internal ear, anterior inferior and superior cerebellar branches and the posterior cerebral artery.

Veins of the head and neck

• Veins of the brain, venous sinuses, diploic veins, emissary veins.

• Veins of the scalp, face, and neck

Veins of the brain

• Cerebral veins, cerebellar veins, veins of the brainstem, all of which drain into neighboring venous sinuses.

Venous sinuses of dura mater

• Apart from the inferior sagittal and straight sinuses, these venous channels lie between the endosteal and meningeal layers of the dura mater. Unlike other veins in the body they run alone, not parallel to arteries.

• Like other veins they are lined by endothelium but contain no valves allowing for bidirectional blood flow in intracranial veins and have walls devoid of muscular tissue. They receive blood from the brain (through the cerebral veins), from the bones of the braincase (via the diploic veins) and from the meninges.

• Together the dural venous sinuses form the major drainage pathways from the brain, predominantly to the internal jugular veins.

Superior sagittal sinus

• The superior sagittal sinus lies between the two leaves of the falx cerebri at their attachment to the cranial vault.

• Extending laterally from the sinus are a variable number of venous lakes. These lie alongside the sinus between the two layers of the dura.

• Opening into the superior sagittal sinus are the superior cerebral veins draining blood from the superior, lateral and medial surfaces of the cerebral hemispheres.

Inferior sagittal sinus

• This is situated between the two leaves of the falx cerebri at its inferior, free margin. Begins just above the crista galli, enlarges as it runs posteriorly. It receives blood from the falx.

Straight sinus• runs posteriorly in the

junction of the falx cerebri and the tentorium cerebelli. It drains the inferior sagittal sinus and receives the great cerebral vein (containing blood from the deep parts of the cerebral hemispheres).

Transverse sinus

• drains the superior sagittal sinus and is usually larger. at the junction of petrous and mastoid parts of the temporal bone the transverse sinus curves downwards to become the sigmoid sinus.

• It receives inferior cerebral, cerebellar, and diploic veins and, near its continuation with the sigmoid sinus, the superior petrosal sinus.

Sigmoid sinus

• its continuation with the transverse sinus to the jugular foramen, producing a deep groove on the endocranial surface of the mastoid part of the temporal bone.

• In the posterior part of the jugular foramen it expands to form the jugular bulb which is continuous below with the internal jugular vein.

Cavernous sinus • The right and left cavernous sinuses lie each side of the body of the

sphenoid. • The walls of the sinus are traversed by the internal carotid artery, the

nerves to the extraocular muscles and the first two divisions of the trigeminal nerve.

• receives blood from the middle cerebral vein (draining the lateral surface of the hemisphere), the sphenoparietal sinus (from the dura mater over the temporal region), and the superior and inferior ophthalmic veins (from the orbit).

• Communications:– Before entering the sinus, the inferior ophthalmic vein communicates with the

pterygoid plexus of veins through the inferior orbital fissure. The cavernous sinus also communicates directly with the pterygoid plexus by emissary veins transmitted through the foramen ovale

The sinus drains into the superior and inferior petrosal sinuses.

Cavernous sinus• Several important structures are related to the

cavernous sinus:– The internal carotid artery curves upwards

from the opening of the carotid canal to enter the posterior part of the sinus.

– The abducent nerve passes the medial wall of the cavernous sinus between the internal carotid artery and the endothelium lining the cavernous sinus.

– The ophthalmic and maxillary divisions of the trigeminal nerve form the lateral wall of the cavernous sinus and the lining endothelium. The ophthalmic nerve is the more superior of the two and divides into its three branches (lacrimal, frontal, and nasociliary) while still in the wall of the sinus.

– The trochlear nerve enters the roof of the cavernous sinus and then runs forwards in its lateral wall, above the ophthalmic nerve

– The oculomotor nerve enters the roof of the sinus in front of the trochlear nerve. It also runs forwards in the lateral wall of the sinus.

Superior petrosal sinus

• The superior petrosal sinus drains out of the posterior part of the cavernous sinus. It ends by entering the junction of the transverse and sigmoid sinuses.

Inferior petrosal sinus

• leaves the posterior part of the cavernous sinus and passes downwards, between the two layers of the dura, along the petrooccipital fissure to enter the anterior part of the jugular foramenit joins the internal jugular vein a short distance below the cranial base.

Diploic veins

• Veins that occupy channels within the bones of the vault of the skull.

Emissary veins

• Valveless veins that pass through the skull bones. They connect veins of the scalp to the venous sinuses

Facial vein

• The forehead is drained by supratrochlear and supraorbital veins which pass downwards towards the inner angle of the eye where they fuse to form the facial vein.

• It is connected to the cavernous sinus through the ophthalmic vein.

• This vein runs downwards and backwards in company with, and just posterior to the facial artery but following a less tortuous course. It receives tributaries corresponding to the branches of the facial artery.

Facial vein

• On the anterior part of the masseter muscle the facial vein crosses the lower border of the mandible, passes through the deep fascia and enters the neck. Here it is joined by the anterior division of the retromandibular vein and then drains into the internal jugular vein.

• A communication channel, the deep facial vein, connects the facial vein with the pterygoid within the infratemporal fossa.

The superficial temporal vein

• It is formed on the side of the scalp. Just above the zygomatic arch it receives the middle temporal vein from the temporalis muscle and a little below this level the transverse facial vein from the side of the face.

• It then enters the parotid gland where it unites with the maxillary vein to form the retromandibular vein.

Maxillary vein

• It is formed in the infratemporal fossa from the pterygoid venous plexus. It joins the superficial temporal vein to form the retromandibular vein.

Retromandibular vein

• It descends within the parotid gland, deep to the facial nerve but superficial to the external carotid artery. While still within the gland or after emerging from it the vein splits into anterior and posterior divisions. The anterior division passes forwards to join the facial vein. The posterior division continues more directly downwards and is joined, either within or just outside the gland, by the posterior auricular vein to form the external jugular vein.

External jugular vein • The external jugular vein is formed by the union of the posterior division

of the retromandibular vein and the posterior auricular vein.• It runs downwards superficial to the sternocleidomastoid muscle, pierces

the deep cervical fascia above the middle of the clavicle, and ends in the subclavian vein. It receives a few small tributaries from adjacent structures.– Anterior jugular vein begins beneath the chin, on each side of the

midline, and passes downwards to the suprasternal region where it pierces the deep fascia and empties into the external jugular vein.

– Occipital vein This large vein drains the occipital region of the scalp. It passes deep between the extensor muscles of the cervical vertebral column and usually opens into the vertebral vein.

– Vertebral vein is formed in the region below the occipital bone by the union of numerous tributaries from the vertebral plexuses and from the deep musculature of the suboccipital region. It passes downwards in the foramina in the transverse processes of the upper six cervical vertebrae and ends by joining the brachiocephalic vein of the same side.

Internal jugular Vein

• Large vein that receives blood from the brain, face and neck. • Starts as a continuation of the sigmoid sinus and leaces the

skull through the jugular foramen to lie at first behind the internal carotid artery.

• Immediately below the cranial base it receives the inferior petrosal sinus.

• The vein passes downwards in the loose part of the carotid sheath lateral to the internal carotid artery and, at a lower level, to the common carotid artery. Between the vein and the arteries is the vagus nerve.

• In the root of the neck the internal jugular vein joins the subclavian vein to form the brachiocephalic vein.

Internal jugular vein

• The internal jugular is crossed superficially by the posterior belly of digastric, omohyoid, and sternocleidomastoid muscles, the posterior auricular and occipital arteries, and the accessory nerve and ansa cervicalis.

• In the lower part of its course it is covered by the infrahyoid muscles.

Internal jugular vein

• Tributaries– inferior petrosal sinus– pharyngeal veins– facial vein– lingual vein– superior thyroid vein– middle thyroid vein

Pterygoid plexus of veins

• This venous plexus lies around within the lateral pterygoid muscle. Its tributaries correspond to the branches of the three parts of the maxillary artery although the area drained is smaller than that supplied by the artery. Blood from the periphery area drains via other routes such as the facial vein.

• It communicates with – the facial vein through the deep facial vein. – cavernous sinus by means of one or more emissary veins passing

through the foramen ovale. – inferior ophthalmic vein through the inferior orbital fissure.

• It drains through the short but wide maxillary vein.

• Its importance in dentistry lies in the fact that it may be punctured by a needle delivering local anaesthetic solution to the posterior superior alveolar nerves, an event which may be followed by copious bleeding into the surrounding tissues. Blood may pass forwards through the inferior orbital fissure into the orbit with production of a ‘black eye’.

• Through its communications the plexus forms a potential route whereby infection may spread from its area of drainage (including the jaws and, through the deep facial vein, the face) to the cavernous sinus.

Pterygoid plexus of veins

Management

• Reassurance of the patient• Cold compresses.

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Education

Vascular system in the head and neck