The veins of the head and neck are responsible for transporting deoxygenated blood from the head and neck back to the heart. Anatomically, the venous drainage from the head and neck can be divided into three parts - the venous drainage of the brain and meninges supplied by the dural venous sinuses, the venous drainage of the scalp and face which is drained by veins that are synonymous with the arteries of the face and scalp which empty into the internal and external jugular veins, and the venous drainage of the neck which is carried out by the anterior jugular veins.
There are three main jugular veins, the external, internal and anterior, which are ultimately responsible for the venous drainage of the entire head and neck.
The external jugular vein is formed by the union of two veins - the posterior auricular vein and the retromandibular vein (posterior branch), and its tributaries supply the majority of the external face. The posterior auricular vein drains the area of scalp superior and posterior to the outer ear, and the retromandibular vein (posterior branch) is itself formed by the maxillary and superficial temporal veins which drain the face. These two veins combine immediately posterior to the angle of mandible, and inferior to the outer ear, forming the external jugular vein. After its formation, the external jugular vein descends down the neck beneath the superficial fascia, running anteriorly to the sternocleidomastoid muscle and crossing it in an oblique, posterior and inferior direction. At the root of the neck, the vein passes underneath the clavicle and terminates by draining into the subclavian vein. Along its route down the neck, the external jugular vein may receive tributary veins, such as the posterior external jugular, transverse cervical and suprascapular veins.
Due to the relatively superficial course of the external jugular vein down the neck, it leaves it vulnerable to damage. If it were severed, such as in the case of a knife slash injury, its lumen is held open due to the thick layer of investing fascia. Air would be drawn into the vein, resulting in cyanosis, and it could potentially stop blood flow through the right atrium. This is a serious medical emergency that requires immediate attention and management, which involves the application of pressure to the wound to stop the bleeding and prevent any further entry of air.
The anterior jugular veins are paired veins that drain the anterior aspect of the neck - often they will communicate with one another via a jugular venous arch. The anterior jugular veins descend down the midline of the neck and typically terminate by draining into the subclavian vein.
The internal jugular vein (IJV) originates in the cranial cavity and acts as a continuation of the sigmoid sinus. The initial part of the internal jugular vein is dilated and is known as the superior bulb, and it exits the skull via the jugular foramen. In the neck, the internal jugular vein descends within the carotid sheath, deep to the sternocleidomastoid muscle and lateral to the common carotid artery. At the base of the neck, posterior to the sternal end of the clavicle, the IJV combines with the subclavian vein to form the brachiocephalic vein. Immediately prior to this, the inferior end of internal jugular vein dilates to form the inferior bulb, and this feature of the IJV has a valve that stops back-flow of blood.
During its descent down the neck, the internal jugular vein receives blood from the facial, lingual, occipital, superior and middle thyroid veins. These veins drain blood from the anterior face, trachea, thyroid, oesophagus, larynx, and muscles of the neck.
The retromandibular vein (posterior branch) is itself formed by the maxillary and superficial temporal veins, which drain the face. These two veins combine immediately posterior to the angle of mandible, and inferior to the outer ear, forming the external jugular vein.
After formation, the external jugular vein descends down the neck within the superficial fascia. It runs anteriorly to the sternocleidomastoid muscle, crossing it in an oblique, posterior and inferior direction. In the root of the neck, the vein passes underneath the clavicle, and terminates by draining into the subclavian vein. Along its route down the neck, the EJV receives tributary veins including the posterior external jugular, transverse cervical and suprascapular veins.
The external jugular vein has a relatively superficial course down the neck, leaving it vulnerable to damage. If it is severed, in an injury such as a knife slash, its lumen is held open due to its thick layer of investing fascia (for more information see Fascial Layers of the Neck).
The anterior jugular veins vary from person to person. They are paired veins, which drain the anterior aspect of the neck. Often they will communicate via a jugular venous arch and descend down the midline of the neck, emptying into the subclavian vein.
The internal jugular vein (IJV) begins in the cranial cavity as a continuation of the sigmoid sinus. The initial part of the internal jugular vein is dilated and is known as the superior bulb. It exits the skull via the jugular foramen.
In the neck, the internal jugular vein descends within the carotid sheath, deep to the sternocleidomastoid muscle and lateral to the common carotid artery. At the base of the neck, posteriorly to the sternal end of the clavicle, the IJV combines with the subclavian vein to form the brachiocephalic vein. Immediately prior to this, the inferior end of internal jugular vein dilates to form the inferior bulb. It has a valve that stops back-flow of blood.
During its descent down the neck, the internal jugular vein receives blood from the facial, lingual, occipital, superior and middle thyroid veins. These veins drain blood from the anterior face, trachea, thyroid, oesophagus, larynx, and muscles of the neck.
In clinical practice, the internal jugular vein can be observed for pulsations – the nature of which provide an estimation of right atrial pressure. When the heart contracts, a pressure wave passes upwards, which can be observed. There are no valves in the brachiocephalic or subclavian veins – so the pulsations are a fairly accurate indication of right atrial pressure.
The dural venous sinuses are spaces between the periosteal and meningeal layers of dura mater, which are lined by endothelial cells. They collect venous blood from the veins that drain the brain and bony skull, and ultimately drain into the internal jugular vein.
The cavernous sinuses are a clinically important pair of dural sinuses. They are located next to the lateral aspect of the body of the sphenoid bone. This sinus receives blood from the superior and inferior ophthalmic veins, the middle superficial cerebral veins, and from another dural venous sinus; the sphenoparietal sinus.
Located within the cavernous sinus is the internal carotid artery, which crosses the sinus. This allows for cooling of the arterial blood before it reaches the brain. Along with the internal carotid artery, the abducens (VI) nerve crosses the sinus. Several nerves are located within the lateral wall of each sinus; oculomotor (III), trochlear (IV), ophthalmic (V1) and maxillary (V2) nerves.
If the cavernous sinus becomes infected, these nerves are at risk of damage. The facial vein is connected to cavernous sinus via the superior ophthalmic vein. The facial vein is valveless – blood can reverse direction and flow from the facial vein to the cavernous sinus. This provides a potential pathway by which infection of the face can spread to the venous sinuses.
The venous drainage of the head and neck is complex. The major veins of this region are the external jugular, anterior jugular, and internal jugular veins. These complex veins work together to drain and carry away blood from the face, neck, brains and skull.
The external jugular vein carries blood from the superficial face and head, while the internal jugular vein carries blood from deep structures such as the brain and skull. The anterior jugular veins collect blood from the anterior surface of the neck and then drain into the subclavian vein. Together, these veins form an important component of the drainage and circulation of the head and neck.
The external jugular vein is particularly vulnerable to injury due to its relatively superficial course down the neck, and if it is cut or slashed, its lumen is held open by its thick layer of investing fascia. If the cavernous sinus becomes infected, the adjacent nerves are at risk of damage, and the facial vein provides a potential pathway for the spread of infection from the face to the venous sinuses.
In clinical practice, the internal jugular vein can be observed for pulsations, which give an estimation of right atrial pressure as there are no valves in the brachiocephalic or subclavian veins. Finally, the dural venous sinuses also play an important role in the drainage of the head and neck as they collect venous blood from the veins that drain the brain and bony skull, and eventually drain into the internal jugular vein.
The venous drainage of the head and neck is complex and it is important to understand not only the anatomy of these veins but also their functions, clinical implications and the potential risks associated with such complex veins. This knowledge is essential for medical practitioners to be able to accurately assess and diagnose any issues related to the venous drainage of the head and neck.
The external jugular vein is the main superficial vein draining many structures in the head and neck. It empties into either the subclavian or the internal jugular vein. The anterior jugular vein starts in the chin area and travels downwards, merging with the subclavian vein in the middle of the neck.
The internal jugular vein is formed by the union of the sigmoid and inferior petrosal sinuses. It then descends down the neck and into the chest, where it empties into the subclavian vein. Several tributaries of the internal jugular vein also drain the dural venous sinuses in the head. These include the transverse sinus, superior sagittal sinus, and inferior sagittal sinus.
Furthermore, in the center of the head lies the cavernous sinus. It communicates with the internal carotid artery and the cavernous sinus. The ophthalmic vein also joins the cavernous sinus, providing tributaries which drain the middle meningeal veins.
The external, anterior, and internal jugular veins are key components in the drainage system of the head and neck. The external jugular serves as the main superficial vein, while the anterior jugular travels downward and merges with the subclavian vein. The cavernous sinus in the middle of the head is where the ophthalmic vein communicates with the internal carotid artery and the cavernous sinus, thus draining the middle meningeal veins. Finally, the internal jugular is formed by the union of the sigmoid and inferior petrosal sinuses, which then proceeds downward to empty into the subclavian vein.
The external jugular vein is responsible for draining superficial structures from the face and neck. It then empties into the internal jugular or subclavian vein. The anterior jugular vein courses from the chin downwards and converges with the subclavian vein in the middle of the neck. The internal jugular vein is formed by the union of the sigmoid and inferior petrosal sinuses and subsequently descends down the neck and into the chest, where it empties into the subclavian vein. Lastly, the cavernous sinus is found in the middle of the head, where it communicates with the internal carotid artery and the cavernous sinus, providing tributaries to drain the middle meningeal veins.
The external jugular vein is the major vessel responsible for draining blood from the face and neck. This is due to its location, running from the parotid gland in the cheek to the clavicle, next to the sternocleidomastoid muscle. The external jugular vein is essential for returning oxygen-depleted blood from the head and neck to the heart where it can be re-oxygenated.
The anterior jugular vein is a vein that runs inferiorly from the chin to the middle of the neck. It contains blood from the superficial tissues of the neck, before converging with the subclavian vein. The anterior jugular vein has an important role, helping to drain the venous blood from the head and neck.
The internal jugular vein is formed at the junction of the sigmoid and inferior petrosal sinuses and travels down the neck, into the chest, and ultimately empties into the subclavian vein. Its main function is to drain blood from the brain, brainstem, dural venous sinuses, and the scalp. It also collects blood from the external jugular and anterior jugular veins and brings it back to the heart.
The cavernous sinus, located in the middle of the head, is a large venous channel that communicates with the internal carotid artery and the cavernous sinus. Additionally, the cavernous sinus receives tributaries from the ophthalmic vein and drains blood from the middle meningeal veins. This large vein serves as an important part of the venous drainage system in the head, and it is responsible for returning oxygen-depleted blood back to the heart.
In addition to the cavernous sinus, there are several tributaries of the internal jugular vein that are important for draining blood from the dural venous sinuses. These include the transverse sinus, superior sagittal sinus, and inferior sagittal sinus. These tributaries join the internal jugular vein which, in turn, collects blood from the external jugular and anterior jugular veins and returns it back to the heart.
The external, anterior, and internal jugular veins are important components of the venous drainage system in the head and neck. The external jugular is responsible for draining superficial structures from the face and neck, while the anterior jugular runs inferiorly from the chin to the middle of the neck. The internal jugular is formed by the union of the sigmoid and inferior petrosal sinuses, and it descends down the neck and into the chest, eventually emptying into the subclavian vein. The cavernous sinus, located in the middle of the head, communicates with the internal carotid artery and the cavernous sinus, and it receives tributaries from the ophthalmic vein and drains blood from the middle meningeal veins. Collectively, these veins are essential for returning oxygen-depleted blood from the head and neck back to the heart where it can be re-oxygenated.
