Neurovasculature Of Head & NeckThe head and neck are more than just features used to identify your friends or relatives. They are complex anatomical entities that are supplied by an equally complicated neurovascular network.
The most important arteries and nerves of the head and neck are the following:
- Internal and external carotid arterie
- Vertebral arteries
- Thyrocervical trunk
- Cranial nerves
- Cervical plexus
- Head and cervical lymph nodes
In this page, we’re going to study each of the above structures together with their respective branches.
Arteries Of Head and Neck
There are several major arteries responsible for the blood supply of the head and neck:
Although some overlap is present and a clear-cut separation on areas supplied cannot be made, the first three arteries in the previous list mainly supply the head, while the last one mainly supplies the structures of the neck. Watch the following videos to learn all about the major arteries of the head.
External Carotid Arteries
The external carotid arteries originate from the common carotid arteries, which in turn stem from the aortic arch (left) and the brachiocephalic artery (right).
Each external carotid artery has several branches: superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, maxillary, and superficial temporal arteries. The majority supply the head and face with oxygenated blood, except the superior thyroid and the ascending pharyngeal arteries which project onto structures of the neck.
|Source||Common carotid artery (at the level of the thyroid cartillage in the larynx)|
Superior thyroid artery (S)
MNEMONIC: Some Anatomists Like Freaking Out Poor Medical Students
|Supplies||(S): Thyroid gland, infrahyoid muscles, sternocleidomastoid muscle
(A): Pharynx, prevertebral muscles, middle ear, cranial meninges
(L): Intrinsic muscles of the tongue, floor of the mouth
(F): Tonsils, palate, submandibular glands
(O): Posterior region of the scalp
(P): Parotid gland, facial nerve, ear, scalp
(M): External acoustic meatus, tympanic membrane, dura mater, calvaria, mandible, gingivae, teeth; temporal, pterygoid, masseter, buccinator muscles
(S): Temporal region of the scalp
The most important ones in this list are the maxillary artery, the largest terminal branch of the external carotid supplying the deep structures of the face, together with the lingual and facial arteries. The latter ones supply the tongue and the muscles of mastication/facial expression, respectively.
Internal Carotid Arteries
The second major arteries of the head are the internal carotid arteries. They also originate from the common carotid arteries and each one is divided into seven segments. The internal carotid arteries are responsible for supplying the brain, eyes, and forehead.
|Segments||Cervical (C1), Petrous (C2), Lacerum (C3), Cavernous (C4), Clinoid (C5), Ophthalmic (C6), Communicating (C7) ('C'mon Please Learn Carotid Clinical Organizing Classification')|
C1 - none
C2 - caroticotympanic and vidian arteries
C3 - none
C4 - tentorial basal, tentorial marginal, meningeal, clivus, inferior hypophyseal arteries
C5 - none
C6 - ophthalmic and superior hypophyseal arteries
C7 - posterior communicating, anterior choroidal, anterior cerebral, middle cerebral arteries
The vertebral arteries stem from the subclavian arteries; two major arteries of the thorax that lie beneath the clavicles. The vertebral arteries ascend through the neck inside the transverse foramina of the cervical vertebrae, all the way to the brain. Through their course, they give off several meningeal, muscular and spinal branches for the nearby structures. The vertebral arteries terminate by anastomosing together as the basilar artery.
The vertebral and internal carotid circulations are not entirely separate entities. They connect at the cerebral arterial circle (of Willis) which is located within the skull at the base of the brain.Watch the following videos to learn more about these arteries.
The thyrocervical trunk is another major artery of the neck. It also originates from the subclavian artery and gives the following branches:
- Inferior thyroid artery
- Ascending cervical artery
- Transverse cervical artery
- Suprascapular artery
These branches are responsible for providing fresh blood to the thyroid gland, lateral muscles of the upper neck, levator scapulae, rhomboids, trapezius, sternocleidomastoid, and surrounding structures.As you can see, the neurovasculature of the head and neck can be quite complex. In order to simplify your learning and cement the knowledge, tackle the following two quizzes.
Veins Of Head And Neck
Now that we have covered the arteries, we will complete the picture of the vasculature of the head and neck by learning about the veins. The main ones draining these two regions are the:
- Facial vein
- Inferior, middle, and superior thyroid veins
- Vertebral veins
- External and internal jugular veins
After accompanying the similarly named arteries and draining the respective structures, the first three sets of veins in the above list join the external and internal jugular veins. In turn, the latter two end up in the subclavian and brachiocephalic veins.
Cervical Plexus & Head Nerves
In addition to the complex vascular network, the head and neck have an equally vast nervous supply. The main nerves of those regions originate from two main sources:
There are twelve cranial nerves in total: olfactory, optic, oculomotor, trochlear, trigeminal, abducent, facial, vestibulocochlear, glossopharyngeal, vagus, accessory, and hypoglossal nerves. The first two originate from the anterior part of the brain, while the remaining ten come from the brainstem.
Take a look at the following resources to learn everything about the cranial nerves of the head.
The cervical plexus is formed by the C1 to C5 spinal nerves, giving off sensory and motor branches to the head and neck:
- Sensory branches: lesser occipital, greater auricular, transverse cervical, supraclavicular
- Motor branches: ansa cervicalis, phrenic nerve, nerve to rhomboids, nerve to serratus anterior
|Sensory Branches||Lesser Occipital, Greater Auricular, Transverse Cervical, Supraclavicular Nerves (OATS)|
|Motor Branches||Ansa Cervicalis, Phrenic Nerve, Nerve to Rhomboid Muscles, Nerve to Serratus Anterior Muscle|
Lesser occipital nerve - skin of the neck and the scalp posterosuperior to the clavicle
Greater auricular nerve - skin over the parotid gland, the posterior aspect of the auricle, and an area of skin extending from the angle of the mandible of the mastoid process
Transverse cervical nerve - skin covering the anterior triangle of the neck
Supraclavicular nerve - skin over the neck and over the shoulder
Ansa cervicalis - infrahyoid muscles
Phrenic nerve - diaphragm, mediastinal pleura, pericardium of the heart
The ansa cervicalis is a nerve loop innervating the infrahyoid muscles in the anterior cervical triangle of the neck. It is located in the carotid triangle and consists of five branches: geniohyoid, thyrohyoid, omohyoid, sternohyoid, and sternothyroid nerves.
Head & Cervical Lymph Nodes
There are several clusters, or aggregations, of lymph nodes in the neck and head. They are important in draining lymph and for the proper functioning of the immune system. In the head, the lymph nodes are organized into groups:
- Fascial group
- Submandibular group
- Parotid group
- Submental group
- Sublingual group
- Mastoid group
- Occipital group
Each group is responsible for draining the structures in its vicinity.
The lymph nodes of the neck are also clustered together. However, rather than being organized in groups, they form three major chains:
- Upper horizontal chain
- Lateral cervical group: superficial group, deep group
- Anterior cervical chain
Similar to the head, each set drains the neighbouring structures.The lymphatic system can be quite difficult to learn and we are aware of that. Therefore, take a look at the following video and article to find out more details and clarify any confusion. You will also get an overview of the neurovasculature of the neck, connecting everything that you’ve learned so far in this page.
Solidify your knowledge about this topic by taking our custom quiz, which covers the nerves, arteries and veins of the head and neck!