Jugular Veins

The jugular veins are major venous channels of the head and neck. They collect blood from the brain, face, scalp, and deep and superficial structures of the neck and return it toward the thorax.

The jugular venous system consists primarily of the internal jugular veins, external jugular veins, and anterior jugular veins. These vessels differ in their size, depth, drainage territories, and termination.

The internal jugular vein is the principal venous drainage pathway for the cranial cavity and many deep structures of the head and neck. The external and anterior jugular veins primarily drain more superficial territories.

Major Jugular Veins

• Internal jugular vein
• External jugular vein
• Anterior jugular vein

Internal Jugular Vein

The internal jugular vein is the largest and most important venous channel in the neck. It drains the intracranial dural venous sinuses and receives tributaries from the face, pharynx, tongue, thyroid gland, and other cervical structures.

It descends through the neck within the carotid sheath and joins the subclavian vein behind the sternoclavicular joint to form the brachiocephalic vein.

Origin of the Internal Jugular Vein

The internal jugular vein begins at the jugular foramen as the continuation of the sigmoid sinus.

Near its origin, the vein has a dilated region called the superior bulb of the internal jugular vein.

Jugular Foramen

The jugular foramen is located at the skull base between the temporal and occipital bones.

In addition to the beginning of the internal jugular vein, the region transmits cranial nerves IX, X, and XI and other vascular structures.

Superior Bulb

The superior bulb is a dilation at the upper end of the internal jugular vein immediately below the jugular foramen.

Its position places it close to structures of the middle and inner ear region.

Course of the Internal Jugular Vein

From the jugular foramen, the internal jugular vein descends through the neck within the carotid sheath.

It travels from the skull base to the root of the neck and terminates by joining the subclavian vein.

Carotid Sheath

The carotid sheath is a fascial compartment extending from the skull base into the root of the neck.

Its major contents include the internal jugular vein, carotid artery, and vagus nerve.

Relationship to the Carotid Arteries

The internal jugular vein usually lies lateral to the internal carotid artery in the upper neck and lateral to the common carotid artery lower in the neck.

The exact relationship can vary with level, body position, respiration, and individual anatomy.

Relationship to the Vagus Nerve

The vagus nerve descends within the carotid sheath between and posterior to the major artery and internal jugular vein.

This close relationship is important during neck surgery and central venous access.

Relationship to the Sternocleidomastoid Muscle

Much of the internal jugular vein lies deep to the sternocleidomastoid muscle.

The muscle therefore provides an important surface landmark when locating the vein clinically.

Termination of the Internal Jugular Vein

At the root of the neck, the internal jugular vein joins the subclavian vein behind the sternoclavicular joint.

The resulting vessel is the brachiocephalic vein.

Inferior Bulb

The lower end of the internal jugular vein commonly contains a second dilation called the inferior bulb.

Valves are typically present near this region and help limit retrograde transmission of pressure from the thorax.

Venous Angle

The junction of the internal jugular and subclavian veins is called the venous angle.

The major lymphatic ducts return lymph to the venous circulation near these junctions.

Internal Jugular Vein Tributaries

The internal jugular vein receives numerous tributaries from structures of the head and neck.

The precise pattern is variable, and some veins may join one another before reaching the internal jugular vein.

Major Tributaries of the Internal Jugular Vein

Tributary	Principal Drainage
Inferior petrosal sinus	Intracranial dural venous system
Common facial vein	Face
Lingual veins	Tongue and floor of mouth
Pharyngeal veins	Pharynx
Superior thyroid vein	Upper thyroid gland and adjacent structures
Middle thyroid vein	Thyroid gland

Inferior Petrosal Sinus

The inferior petrosal sinus drains venous blood from the cavernous sinus region and terminates near the superior portion of the internal jugular vein.

It contributes to the connection between intracranial dural venous sinuses and extracranial venous circulation.

Facial Venous Drainage

Venous blood from the face reaches the internal jugular system primarily through the facial vein, commonly through a common facial venous trunk.

Facial veins have important communications with deeper venous networks of the head.

Lingual Veins

The lingual veins drain the tongue and portions of the floor of the mouth.

They may enter the internal jugular vein independently or join neighboring venous tributaries before termination.

Pharyngeal Veins

The pharyngeal venous plexus drains the pharyngeal wall and communicates with neighboring venous networks.

Its veins ultimately drain into the internal jugular venous system.

Superior Thyroid Vein

The superior thyroid vein drains the upper portion of the thyroid gland and nearby laryngeal structures.

It usually terminates in the internal jugular vein, either independently or through a common trunk.

Middle Thyroid Vein

The middle thyroid vein drains the thyroid gland directly into the internal jugular vein.

It is clinically important during thyroid surgery because it crosses laterally from the gland toward the vein.

Intracranial Venous Drainage

The internal jugular veins form the principal pathways for blood leaving the cranial cavity.

Blood collected by the dural venous sinuses reaches the sigmoid sinus, which continues through the jugular foramen as the internal jugular vein.

External Jugular Vein

The external jugular vein is a superficial vein of the neck that drains much of the scalp and superficial face.

It descends superficial to the sternocleidomastoid muscle and terminates in the subclavian vein.

Formation of the External Jugular Vein

The external jugular vein usually forms near the angle of the mandible by the union of the posterior division of the retromandibular vein with the posterior auricular vein.

Course of the External Jugular Vein

The external jugular vein descends obliquely across the superficial surface of the sternocleidomastoid muscle.

Near the root of the neck, it pierces the investing layer of deep cervical fascia and enters the subclavian vein.

Relationship to the Sternocleidomastoid Muscle

The superficial course of the external jugular vein over the sternocleidomastoid muscle makes it visible in many individuals, particularly when venous pressure rises.

This contrasts with the internal jugular vein, which lies deep to the muscle for much of its course.

External Jugular Vein Tributaries

The external jugular vein receives several superficial cervical veins. Tributary patterns vary substantially.

Tributary	Drainage Territory
Posterior external jugular vein	Posterior scalp and neck
Transverse cervical vein	Posterior triangle and adjacent regions
Suprascapular vein	Scapular region
Anterior jugular vein	Anterior neck, variably

Anterior Jugular Vein

The anterior jugular vein is a relatively small superficial vein draining the anterior neck.

It usually begins near the hyoid region from superficial submental venous channels and descends near the anterior midline.

Course of the Anterior Jugular Vein

The anterior jugular vein descends between the midline and anterior border of the sternocleidomastoid muscle.

Near the lower neck, it turns laterally and may terminate in the external jugular or subclavian vein.

Jugular Venous Arch

The right and left anterior jugular veins commonly communicate through a transverse channel called the jugular venous arch.

This arch lies in the suprasternal region and provides communication between the superficial venous systems of the two sides of the neck.

Suprasternal Space

The jugular venous arch is associated with the fascial space above the manubrium.

Its position is important during procedures involving the lower anterior neck and trachea.

Comparison of the Major Jugular Veins

Feature	Internal Jugular	External Jugular	Anterior Jugular
Position	Deep	Superficial	Superficial anterior neck
Major drainage	Brain and deep head and neck	Scalp and superficial head and neck	Anterior neck
Course	Within carotid sheath	Across sternocleidomastoid	Near anterior midline
Typical termination	Joins subclavian to form brachiocephalic vein	Subclavian vein	External jugular or subclavian vein

Venous Communications

The jugular veins communicate extensively with one another and with facial, vertebral, intracranial, and thoracic venous systems.

These communications provide alternative routes for venous return when individual channels are compressed or obstructed.

Vertebral Venous System

The vertebral veins and vertebral venous plexuses provide additional pathways for drainage of the head and neck.

They communicate with intracranial and cervical veins and can contribute significantly to venous return when jugular flow is altered.

Valves

The internal and external jugular veins contain valves, although the number and effectiveness of these valves vary.

A pair of valves is commonly located near the lower end of the internal jugular vein.

Function

The jugular veins return venous blood from the head and neck toward the heart.

The internal jugular veins provide the principal pathway for intracranial venous return, while the external and anterior jugular veins drain more superficial territories.

Overall Venous Pathway

A simplified deep venous pathway is:

Dural venous sinuses → Sigmoid sinus → Internal jugular vein → Brachiocephalic vein → Superior vena cava → Right atrium

Jugular Venous Pressure

Pressure changes in the right atrium are transmitted backward through the superior vena cava and central veins.

Observation of venous pulsations in the neck can therefore provide information about right-sided cardiac filling pressure and hemodynamics.

Internal Jugular Venous Pulsation

The clinically assessed jugular venous pulse reflects pressure changes in the right atrium transmitted through the central venous system.

The right internal jugular vein provides a relatively direct anatomical pathway toward the superior vena cava and right atrium.

External Jugular Distension

The external jugular vein may become visibly distended when central venous pressure is elevated.

However, its superficial course, valves, and local anatomy mean that it is not identical to the internal jugular venous pulse used for formal clinical assessment.

Central Venous Access

The internal jugular vein is commonly used for central venous access because of its size and relatively direct connection with the brachiocephalic vein and superior vena cava.

The right internal jugular vein often provides a particularly direct route into the central venous circulation.

Anatomical Landmarks for Internal Jugular Access

The internal jugular vein lies in close relationship to the sternocleidomastoid muscle and common carotid artery.

Modern central venous access commonly uses ultrasound to identify the vein and surrounding structures directly.

Ultrasound Appearance

On ultrasound, the internal jugular vein is generally compressible and changes caliber with respiration and pressure.

The adjacent carotid artery is typically less compressible and pulsatile.

Relationship to the Carotid Artery During Procedures

Because the internal jugular vein and carotid artery lie close together, precise localization is important during venous access.

Their relationship may vary between individuals and can change with head position.

Jugular Vein Thrombosis

Thrombosis can occur in the internal or external jugular veins.

Potential associations include intravascular catheters, infection, malignancy, trauma, surgery, and other conditions affecting venous flow or coagulation.

Internal Jugular Vein Thrombosis

Internal jugular vein thrombosis can obstruct venous drainage from the head and neck and may extend into central thoracic veins.

Collateral venous pathways can enlarge when obstruction develops gradually.

Septic Thrombophlebitis

Infection involving deep structures of the head and neck can occasionally spread to the internal jugular vein and produce septic thrombophlebitis.

The close connections between pharyngeal, facial, and deep cervical venous networks provide anatomical pathways for spread.

Lemierre Syndrome

Lemierre syndrome is classically associated with septic thrombophlebitis of the internal jugular vein following an oropharyngeal infection.

Its anatomical basis involves spread from infected tissues of the pharyngeal region to deep cervical veins.

External Jugular Vein Access

The external jugular vein can sometimes be used for peripheral or central venous access because of its superficial position.

Its angulation and valves can make advancement of a catheter toward the central veins more difficult than through the internal jugular vein.

Air Embolism and the External Jugular Vein

The external jugular vein is tethered where it pierces deep cervical fascia near the root of the neck.

If injured at this location, the vein may remain open rather than collapsing completely, creating a potential route for air entry under suitable pressure conditions.

Neck Surgery

The jugular veins are major structures encountered during surgery of the neck.

The internal jugular vein is particularly important during procedures involving cervical lymph nodes, thyroid gland, carotid sheath, and deep neck spaces.

Neck Dissection

The internal jugular vein is a major anatomical landmark during cervical lymph node dissection.

Its preservation or removal depends on the specific surgical procedure and extent of disease.

Thyroid Surgery

The internal jugular vein lies lateral to the thyroid region and receives thyroid venous tributaries.

The middle thyroid vein, in particular, may cross from the thyroid gland directly to the internal jugular vein.

Tracheostomy

Anterior jugular veins and the jugular venous arch are relevant during procedures involving the lower anterior neck.

Variation in these superficial veins should be considered when approaching the trachea surgically.

Imaging

Ultrasound, CT, and MRI can demonstrate the jugular veins and surrounding cervical structures.

Imaging is useful for evaluating thrombosis, compression, congenital variation, masses, and catheter position.

Doppler Ultrasound

Doppler ultrasound can assess venous patency, direction of flow, respiratory variation, and suspected thrombosis.

It is particularly useful because the internal jugular vein is accessible from the surface of the neck.

CT and MRI

Cross-sectional imaging can trace the jugular veins from the skull base through the neck and into the thoracic inlet.

It can also demonstrate relationships with lymph nodes, tumors, arteries, deep neck spaces, and other structures.

Anatomical Variations

The jugular veins show considerable variation in size, tributaries, communications, and symmetry.

One internal jugular vein may be larger than the other, and superficial venous patterns can differ markedly between individuals.

Internal Jugular Vein Size

The right internal jugular vein is often larger than the left, although considerable individual variation occurs.

Vein diameter also changes with body position, respiration, hydration, and intrathoracic pressure.

External Jugular Vein Variations

The formation and tributaries of the external jugular vein are variable.

Its connections with the facial, retromandibular, anterior jugular, and transverse cervical venous systems may differ from the typical pattern.

Anterior Jugular Vein Variations

The anterior jugular veins may differ in size and number and can occasionally be replaced by a single prominent midline vessel.

The configuration of the jugular venous arch is also variable.

Embryological Development

The jugular venous system develops through remodeling of embryonic cardinal veins and their connections.

Changes in these embryonic channels contribute to formation of the internal jugular veins, brachiocephalic veins, and other major cervical and thoracic veins.

Key Anatomical Relationships

Structure	Relationship to Jugular Venous System
Sigmoid sinus	Continues as internal jugular vein
Carotid artery	Usually medial to internal jugular vein
Vagus nerve	Within carotid sheath between and posterior to artery and vein
Sternocleidomastoid	Internal jugular lies deep, external jugular crosses superficially
Subclavian vein	Joins internal jugular to form brachiocephalic vein
Thoracic duct	Terminates near left venous angle

Key Features of the Jugular Veins

Feature	Key Point
Main deep vein	Internal jugular vein
Main superficial vein	External jugular vein
Anterior superficial drainage	Anterior jugular vein
Internal jugular origin	Continuation of sigmoid sinus at jugular foramen
Internal jugular termination	Joins subclavian vein to form brachiocephalic vein
External jugular termination	Subclavian vein
Major intracranial drainage	Internal jugular veins
Important clinical uses	Central venous access and jugular venous pressure assessment

Anatomical and Clinical Importance

The jugular veins form the principal venous drainage pathways of the head and neck. The internal jugular veins return most intracranial venous blood and receive important deep cervical tributaries, while the external and anterior jugular veins drain predominantly superficial structures.

The close relationship of the internal jugular vein to the carotid arteries, vagus nerve, sternocleidomastoid muscle, and deep cervical structures makes it an essential landmark in head and neck anatomy. Its direct connection with the brachiocephalic vein also makes it a major route for central venous access.

The jugular venous system is clinically important in evaluation of central venous pressure, venous thrombosis, deep neck infection, cervical surgery, and vascular access. Its numerous communications with intracranial, facial, vertebral, and thoracic veins provide alternative routes for venous return but can also create pathways for the spread of disease.