Arteries of the Face and Neck
The blood supply of the head and neck comes mainly from 2 sources; the paired Common Carotid Arteries (the right arising from the brachiocephalic trunk and the left arising directly from the arch of the aorta), and the paired Vertebral Arteries (both arising from the subclavian arteries). The vertebral arteries ascend to supply the vertebrobasilar system of arteries of the brain, whilst the common carotid arteries bifurcate into the external carotid arteries - the main arteries of the face, and internal carotid arteries, which ascend to supply intracranial structures. Some of the blood supply of the structures of the neck is derived from branches of other arteries, for example the subclavian arteries. It is important to note that the arteries covered are paired, there is one on either side of the head/neck.
Aorta, brachiocephalic trunk, subclavian and common carotid arteries
- Ascending aorta: arises from vestibule of left ventricle @ level left 3rd costal cartilage and passes across to right 2nd costal cartilage. Covered by pericardium (fibrous and serous). Relations: anterior - pulmonary trunk, right auricle, posterior - left atrium, right pulmonary artery, right main bronchus, left - pulmonary trunk, left auricle, right - superior vena cava, right atrium. Branches: Right and left coronary arteries.
- Arch of Aorta: Begins posterior to manubriosternal joint (angle of Louis) @ level 2nd costal cartilage, passes posterolaterally to left over left main bronchus to become descending aorta at level of T4 vertebral body. Lies behind manubrium. Relations: anterior-left = left phrenic nerve, nerves to cardiac plexus (from vagus/sympathetic trunk), left superior interostal vein, Left lateral = left lung + pleura, posterior-right = trachea, deep cardiac plexus, left recurrent laryngeal nerve (from left vagus), oesophagus, thoracic duct, T4 vertebral body, Inferiorly = bifurcation of pulmonary trunk, left main bronchus, ligamentum arteriosum, left recurrent laryngeal nerve. Branches: Brachiocephalic trunk (right side), Left common carotid artery, left subclavian artery.
- Brachiocephalic trunk: 1st branch of arch of aorta, passes superior-posterior-laterally. Starts anterior to trachea, ends right lateral to it. Relations: anterior = left brachiocephalic vein + L inferior thyroid vein, remants of thymus, posterior-left = trachea, left = left common carotid artery, right = right brachiocephalic vein and superior vena cava, pleura/lung, cardiac branches vagus nerve, posterolateral (posterior-right) = right vagus.Bifurcates into right subclavian and right common carotid arteries.
- Left common carotid artery: 2nd branch of arch of aorta. Relations: anteriorly = include left brachiocephalic vein, remnant of thymus, posteriorly = trachea, posterior-left = left subclavian artery, left recurrent laryngeal nerve, thoracic duct, oesophagus, right = brachiocephalic trunk, left = vagus, left phrenic nerve, pleura/lung. See later for carotid arteries in neck
- Left subclavian artery: 3rd branch arch of aorta. Lies posterior/left of left common carotid artery, ascends posterior to joining of left internal jugular and left subclavian veins. Anteriorly lie left vagus and phrenic nerves.
- Descending aorta: continuation of arch of aorta, begins at level of T4 vertebral body. Supplies blood to thoracic walls (via posterior intercostal arteries), and some of thoracic viscera, finally piercing diaphragm at the T12 vertebral level to continue as the abdominal aorta carrying blood to the abdomen, pelvis and lower limbs.
Common carotid artery and its branches - cervical portions
The right common carotid artery arises from the brachiocephalic trunk, and the left directly from the arch of the aorta. The arteries ascend from behind the sternoclavicular joints to around the level of the superior border of the thyroid cartilage / hyoid bone / ~ C3 vertebra (differs in many due to anatomical variation). They are contained within the carotid sheaths. A discussion of anatomical relations is after this section.
The carotid body lies at the bifurcation - this is involved in chemoreception (detection of PaO2 and PaCO2) - information is transmitted from here to the CNS via the glossopharyngeal nerve.
Branches of the common carotid artery:
The carotid body lies at the bifurcation - this is involved in chemoreception (detection of PaO2 and PaCO2) - information is transmitted from here to the CNS via the glossopharyngeal nerve.
Branches of the common carotid artery:
- Internal carotid artery: Ascends to the skull from the bifurcation of the common carotid artery, supplies intracranial structures and the orbit. At its origin is the carotid sinus - a dilatation in the wall involved in baroreception (and therefore control of blood pressure); information is carried to the CNS from here via the glossopharyngeal nerve. This artery will be covered in more detail in the arteries of the brain section.
- External carotid artery: Arises at the bifurcation of the common carotid artery, has 8 branches that supply face and neck structures. It enters the substance of the parotid gland where it bifurcates into its terminal branches, the maxillary and superficial temporal arteries.
Anatomical relations of common carotid artery
Transverse section at level of 6th cervical vertebra
The common carotid artery is contained within the carotid sheath. The sheath contains also the vagus nerve and the internal jugular vein. The anatomical relations of the carotid sheath and common carotid arteries vary depending on the level in the neck.
In the lower neck the common carotid artery is covered by:
The artery is crossed anteriorly by:
Posterior to the artery:
Medially:
Laterally:
In the lower neck the common carotid artery is covered by:
- Skin, superficial fascia and platysma
- Sternocleidomastoid
- infrahyoid muscles
The artery is crossed anteriorly by:
- Various vessels including the superior thyroid artery and superior and middle thyroid veins.
- Parts of the hypoglossal nerve
Posterior to the artery:
- Sympathetic chain
- Longus colli and longus capitis muscles (posterior to sympathetic chain)
Medially:
- Oesophagus, trachea, thyroid gland
- Larynx and pharynx (higher up)
- Recurrent laryngeal nerve
Laterally:
- IJV and vagus nerve (in carotid sheath)
External carotid artery and its branches
Arises at the bifurcation of the common carotid artery around the level of the C3 vertebra. Has 8 branches that supply the tissues of the head and neck.
Its branches are as follows (direction it comes off external carotid in brackets):
Its branches are as follows (direction it comes off external carotid in brackets):
- Superior thyroid artery (anterior): supplies thyroid gland, larynx, pharynx, infrahyoid muscles.
- Lingual artery (anterior): supplies tongue, suprahyoid muscles, tonsils, soft palate, sublingual and submandibular glands.
- Facial artery (anterior): supplies tonsil, soft palate, submandibular gland, lips, facial musculature.
- Occipital artery (posterior): supplies upper posterior neck and back of scalp up to vertex.
- Posterior auricular artery (posterior): supplies auricle and adjacent scalp.
- Ascending pharyngeal artery (posteromedial): supplies pharynx, tonsil, soft palate, pharyngotympanic (eustachian) tube.
- Maxillary artery (anterior): in general supplies similar structures to those supplied by the maxillary and mandibular branches of the trigeminal nerve. (See later)
- Superficial temporal artery (superior): supplies parotid gland, masseter, scalp (lateral anterior to vertex)
Model of head and neck vessels (external carotid) - can you see which vessels are missing from the model??
| external_carotid_and_branches.docx |
Maxillary artery
Right maxillary artery, showing most of branches (some are missing - see right for schematic including all branches)
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Schematic of the branches of the maxillary artery
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The Maxillary artery arises at the termination of the external carotid artery, within the substance of the parotid gland. It passes laterally to the lateral pterygoid muscle in the infratemporal fossa, giving off numerous branches (see two diagrams above) before entering the pterygopalatine fossa via the pterygomaxillary fissure. In here it gives off further branches supplying structures such as the nasal cavities, the pharynx and a small branch that enters the cranial vault (artery of pterygoid canal).
The branches of the maxillary artery are as follows:
The branches of the maxillary artery are as follows:
- Deep auricular
- Anterior tympanic: supplies middle ear
- Middle meningeal: supplies ~80% of dura mater and bones of cranial vault
- Accessory meningeal: contributes small supply to dura/bones of cranial vault
- Inferior alveolar: supplies mandible, mandibular teeth, gingiva. Gives off the mylohyoid artery
- 2 deep temporal arteries (anterior and posterior): Temporalis muscle and surrounding tissues
- Muscular / Pterygoid arteries: Medial and lateral pterygoid muscles
- Masseteric: masseter muscle
- Buccal: cheek ans associated muscles
- Pharyngeal: nasopharynx
- Descending palatine arteries: bifurcate into greater and lesser palatine, to supply hard and soft palate respectively
- Sphenopalatine artery: Nasal cavity, hard palate (passes through incisive canal into oral cavity)
- Posterior superior alveolar: maxillary sinus, upper molars
- Artery of pterygoid canal:
- Infra-orbital: gives off middle superior alveolar artery (supplies maxillary premolars and maxillary sinus), anterior superior alveolar artery (supplies maxillary canines + incisors + maxillary sinus), continues through infraorbital foramen to supply skin of cheek
Inferior alveolar nerve (use arrows to navigate between slides 1 and 2):
| maxillary_artery_branches.docx |
| maxillary_artery_page_2_relations_and_foraminae.docx |
Superficial temporal, occipital, posterior auricular and facial arteries
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Superficial temporal artery: has numerous branches supplying areas of the scalp, temporalis muscles, auricle etc. These branches are as follows:
Occipital artery: supplies posterior neck structures and scalp up to vertex Posterior auricular: supplies auricle and small part of posterolateral scalp Facial artery: from its origin initially passes deep to mandible and gives some branches to supply intraoral structures. It then passes close to the submandibular gland to curl around the mandible and emerge on the lateral aspect of the body just anterior to the masseter. It continues up obliquely towards the medial angle of the eye, giving branches to facial muscles and structures. Some of its branches are as follows:
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Subclavian artery and its branches
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The subclavian arteries arise, on the right from the brachiocephalic trunk and on the left directly from the arch of the aorta. In the image, we see the right subclavian artery passing from the brachiocephalic trunk posteriorly to the anterior scalene muscle. It can be divided into 3 parts depending on its relation to the anterior scalene:
1st part - before anterior scalene. Branches are:
The subclavian artery then continues over the first rib into the axilla, where it becomes known as the axillary artery which goes on to supply the upper limb. |