MAJOR VESSELS OF THE HEAD NECK Dr Zeenat

MAJOR VESSELS OF THE HEAD & NECK Dr. Zeenat Zaidi

Arteries of the Head & Neck Common carotid arteries Subclavian arteries

Common Carotid Artery • Is a paired structure • The left and right common carotid arteries follow the same course with the exception of their origin. • Right common carotid artery originates in the neck from the brachio-cephalic artery behind the right sternoclavicular joint • Left common carotid artery arises in the superior mediastinum from the arch of the aorta * *

• The common carotid artery runs upward through the neck under cover of the anterior border of the sternocleidomastoid muscle • At the upper border of the thyroid cartilage, (opposite C 4 vertebra) it divides into the d external and internal carotid arteries The common carotid artery is embedded in a connective tissue sheath, called the carotid sheath, sheath throughout its course and is closely related to the internal jugular vein and vagus nerve

Carotid Sinus • a localized dilatation at the point of division of the common carotid artery • has thinner tunica media of the sinus is than elsewhere, but relatively thick adventitia, and contains numerous nerve endings derived from the glossopharyngeal nerve • serves as a reflex pressoreceptor mechanism: A rise in blood pressure causes a slowing of the heart rate and vasodilatation of the arterioles • In cases of carotid sinus hypersensitivity, pressure on one or both carotid sinuses can cause excessive slowing of the heart rate, a fall in blood pressure, and cerebral ischemia with fainting Carotid Body • a small structure that lies posterior to the point of bifurcation of the common carotid artery • is innervated by the glossopharyngeal nerve. • is a chemoreceptor, being sensitive to excess carbon dioxide and reduced oxygen tension in the blood. Such a stimulus reflexly produces a rise in blood pressure and heart rate and an increase in respiratory movements.

Relations • Anterolaterally: skin, fascia, sternocleidomastoid, sternohyoid, sternothyroid, superior belly of the omohyoid • Posteriorly: transverse processes of the lower four cervical vertebrae, prevertebral muscles, sympathetic trunk. In the lower part of the neck are the vertebral vessels. • Medially: larynx and pharynx and, below these, the trachea and esophagus. lobe of the thyroid gland. • Laterally: internal jugular vein and, • Apart from the two posterolaterally, vagus nerve terminal branches, the common carotid artery gives off no branches.

External Carotid Artery • One of the terminal branches of the common carotid artery • Supplies structures in the neck, face, and scalp; it also supplies the tongue and the maxilla. • Begins at the level of the upper border of the thyroid cartilage(C 4) • Terminates in the substance of the parotid gland behind the neck of the mandible by dividing into the superficial temporal and maxillary arteries. • Close to its origin, the artery emerges from undercover of the sternocleidomastoid muscle, where its pulsations can be felt. • At first, lies medial to the internal carotid artery, later passes backward and lateral to it. • It is crossed by the posterior belly of the digastric and the stylohyoid

• Anterolaterally: Relations • Overlapped at its beginning by the anterior border of the sternocleidomastoid. • Above this level, covered by skin and fascia. Crossed by hypoglossal nerve, posterior belly of the digastric and stylohyoid muscles. • Within the parotid gland, it is crossed by the facial nerve. • Internal jugular vein first lies lateral to the artery and then posterior to it. • Medially: • Wall of the pharynx and internal carotid artery. • Stylopharyngeus muscle, glossopharyngeal nerve, and pharyngeal branch of the vagus pass between the external and internal carotid arteries

Branches • Superior thyroid artery: • curves downward to the upper pole of the thyroid gland • accompanied by the external laryngeal nerve • Ascending pharyngeal artery: • ascends along and supplies the pharyngeal wall • Lingual artery: • loops upward and forward and supplies the tongue

• Facial artery • Loops upward close to the outer • • surface of the pharynx and the tonsil Lies deep to the submandibular salivary gland Emerges and bends around the lower border of the mandible. It then ascends over the face close to the anterior border of the masseter muscle Then ascends around the lateral margin of the mouth and terminates at the medial angle of the eye Supplies tonsil, submandibular gland & muscles and skin of the face. Facial artery

• Occipital artery: • Supplies the back of the scalp • Posterior auricular artery: • Supplies the auricle and the scalp • Superficial temporal artery: • Ascends over the zygomatic arch, (where it may be palpated just in front of the auricle). • Accompanied by the auriculotemporal nerve • supplies the scalp. • Maxillary artery: • Runs forward medial to the neck of the mandible and enters the pterygopalatine fossa of the skull. Superficial Temporal a. Posterior auricular a. Occipital artery

Branches of Maxillary Artery Inferior alveolar artery Middle meningeal artery Small branches to the external auditory meatus and the tympanic membrane Small muscular branches supply the muscles of mastication boy

Internal Carotid Artery • Begins at the bifurcation of the common carotid artery at the level of the upper border of the thyroid cartilage • Supplies brain, eye, forehead, and part of nose. • Ascends in the neck embedded in the carotid sheath with the internal jugular vein and vagus nerve. • At first it lies superficially; it then passes deep to the parotid salivary gland • Leaves the neck by passing into the cranial cavity through the carotid canal in the petrous part of the temporal bone. • Passes upward and forward in the cavernous venous sinus • Leaves the sinus and passes upward again medial to the anterior clinoid process of the sphenoid bone. • Inclines backward, lateral to the optic chiasma, and terminates by dividing into the anterior and the middle cerebral arteries. It gives off no branches in the neck

NOTE. Atherosclerosis in the neck…. visual defect due to insufficient blood flow through central artery of retina. Insufficient blood flow in middle cerebral artey… motor & sensory loss

Relations • Anterolaterally: • Below the digastric : skin, fascia, anterior border of the sternomastoid, and hypoglossal nerve • Above the digastric: stylohyoid and stylopharyngeus muscles, glossopharyngeal nerve, pharyngeal branch of vagus, parotid gland, and external carotid artery • Posteriorly: sympathetic trunk , longus capitis muscle, and transverse processes of upper three cervical vertebrae • Medially: pharyngeal wall and superior laryngeal nerve • Laterally: internal jugular vein and vagus nerve

Subclavian Artery Right Subclavian Artery • Arises from the brachiocephalic artery, behind the right sternoclavicular joint • Arches upward and laterally over the pleura and between the scalenus anterior and medius muscles. • At the outer border of the first rib, it becomes the axillary artery. Left Subclavian Artery • Arises from the arch of the aorta in the thorax. • Ascends to the root of the neck and then arches laterally in a manner similar to that of the right subclavian artery The scalenus anterior muscle passes anterior to the artery on each side and divides it into three parts.

First Part of the Subclavian Artery Relations : Anteriorly : common carotid , vagus, symp. trunk (ansa subclavia), int. j. v. & left phrenic N. Posteriorly : apex of lung & pleura, Rt. recurrent laryngeal N. . . Extends from the origin of the subclavian artery to the medial border of the scalenus anterior muscle Branches Vertebral artery Thyrocervical trunk Internal thoracic artery.

• The vertebral artery: • Ascends in the neck through the foramina in the transverse processes of the upper six cervical vertebrae • Passes medially above the posterior arch of the atlas and then ascends through the foramen magnum into the skull • On reaching the anterior surface of the medulla oblongata of the brain at the level of the lower border of the pons, it joins the vessel of the opposite side to form the basilar artery. • Branches in the neck: Spinal and muscular arteries • Relations : Anteriorly : C. C. artery and crossed by thoracic duct. Posteriorly : T. procees of 7 thc. v. & stellate ganglion.

• The thyrocervical trunk is a short trunk that gives off three terminal branches • The inferior thyroid artery ascends to the posterior surface of the thyroid gland, where it is closely related to the recurrent laryngeal nerve. It supplies the thyroid and the inferior parathyroid glands. • The superficial cervical artery is a small branch that crosses the brachial plexus • The suprascapular artery runs laterally over the brachial plexus and follows the suprascapular nerve onto the back of the scapula

The internal thoracic artery: Descends into the thorax behind the first costal cartilage and in front of the pleura Descends vertically one fingerbreadth lateral to the sternum In the sixth intercostal space, it divides into the superior epigastric and the musculophrenic arteries.

Scalenus Anterior & Phrenic nerve : ØNote, the roots of phrenic N. lie laterally to scalenus anterior, but phrenic N. lies anterior to scalenus anterior.

Second Part of the Subclavian Artery • Lies behind the scalenus anterior muscle • Relations : Anteriorly : scalenus ant. Posteriorly : cervical pleura & apex of lung. Branches • The costocervical trunk runs backward over the dome of the pleura and divides into the superior intercostal artery, which supplies the first and the second intercostal spaces, and the deep cervical artery, which supplies the deep muscles of the neck.

Third Part of the Subclavian Artery • Extends from the lateral border of the scalenus anterior muscle to the lateral border of the first rib, where it becomes the axillary artery. • Is closely related to the nerves of the brachial plexus. Branches • Usually has no branches. Occasionally, superficial cervical and suprascapular arteries, or both arise from this part.

Veins of the Head & Neck May be divided into: Veins of the brain, venous sinuses, diploic veins, and emissary veins Veins of the scalp, face, and neck

Facial Vein • Formed at the medial angle of the eye by the union of the supraorbital and supratrochlear veins. • Connected through the ophthalmic veins with the cavernous sinus. • Descends down the face with the facial artery and passes around the lateral side of the mouth. • Crosses the mandible, is joined by the anterior division of the retromandibular vein, and drains into the internal jugular vein.

Superficial Temporal Vein • Formed on the side of the scalp • Follows the superficial temporal artery and the auriculotemporal nerve • Enters the parotid salivary gland, where it joins the maxillary vein to form the retromandibular vein.

Maxillary Vein • Formed in the infratemporal fossa from the pterygoid venous plexus • Joins the superficial temporal vein to form the retromandibular vein. Retromandibular Vein • Formed by the union of the superficial temporal and the maxillary veins • On leaving the parotid salivary gland, divides into an anterior branch, which joins the facial vein, and a posterior branch, which joins the posterior auricular vein to form the external jugular vein.

External Jugular Vein • Formed behind the angle of the jaw by the union of the posterior auricular vein with the posterior division of the retromandibular vein • Passes straight down the neck in the superficial fascia, deep to platysma • Lies superficial to the sternocleidomastoid muscle throughout its course, crossing it diagonally as it descends. • Reaching the lower part of the neck, superior to the clavicle and immediately posterior to the sternocleidomastoid muscle, it pierces the investing layer of cervical fascia, and enters the subclavian vein behind the middle of the clavicle. .

Tributaries • Posterior external jugular vein from the back of the scalp and neck • Transverse cervical vein from the skin and the fascia over the posterior triangle • Suprascapular vein from the back of the scapula

Anterior jugular vein • Begins below the chin from veins draining the lower lip and mental region • Descends in the front of the neck close to the midline • Just above the sternum, is joined to the opposite vein by the jugular arch. • Joins the external jugular vein deep to the sternocleidomastoid muscle

Internal Jugular Vein • A large vein that receives blood from the brain, face, and neck • Starts as a continuation of the sigmoid sinus and leaves the skull through the jugular foramen. • Descends through the neck in the carotid sheath lateral to the vagus nerve and the internal and common carotid arteries. • Ends by joining the subclavian vein behind the medial end of the clavicle to form the brachiocephalic vein • Throughout its course, it is closely related to the deep cervical lymph nodes. • Has a dilatation at its upper end called the superior bulb and another near its termination called the inferior bulb. Directly above the inferior bulb is a bicuspid valve.

Relations • Anterolaterally: skin, fascia, sternocleidomastoid, and parotid salivary gland. • Lower part is covered by sternothyroid, sternohyoid, and omohyoid muscles • Upper part crossed by stylohyoid, posterior belly of the digastric, and spinal part of accessory nerve. • The chain of deep cervical lymph nodes runs alongside the vein. • Posteriorly: transverse processes of the cervical vertebrae, levator scapulae, scalenus medius, scalenus anterior, cervical plexus, phrenic nerve, thyrocervical trunk, vertebral vein, and first part of the subclavian artery. On the left side it passes in front of the thoracic duct. Medially: Above lie the internal carotid artery and 9 th, 10 th, 11 th, and 12 th cranial nerves. Below lie the common carotid artery and the vagus nerve

Tributaries Inferior petrosal sinus Facial vein Pharyngeal veins Lingual vein Superior thyroid vein Middle thyroid vein

Subclavian Vein • Continuation of the axillary vein at the outer border of the first rib • Joins the internal jugular vein to form the brachiocephalic vein • Receives the external jugular vein • In addition, it receives the thoracic duct on the left side and the right lymphatic duct on the right. Relations • Anteriorly: The clavicle • Posteriorly: The scalenus anterior muscle and the phrenic nerve • Inferiorly: The upper surface of the first rib

Internal Jugular Vein Catheterization • The internal jugular vein is remarkably constant in position. • In the posterior approach, the tip of the needle and the catheter are introduced into the vein about two fingerbreadths above the clavicle at the posterior border of the sternocleidomastoid muscle • In the anterior approach, with the patient's head turned to the opposite side, the triangle formed by the sternal and clavicular heads of the sternocleidomastoid muscle and the medial end of the clavicle are identified. A shallow skin depression usually overlies the triangle. The needle and catheter are inserted into the vein at the apex of the triangle in a caudal direction

NOTE. v. Structures superficial to sternocleidomastoid are : v skin, platysma, external j. v. , great auricular N. , transverse cervical N. & investing layer of deep cervical fascia.

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