Muscles
449
92
RETPAHC
fourth cervical spinal nerves also enter the muscle. Although these cervi supplied by the facial nerve. The different innervation of the two parts
cal rami were believed to be solely proprioceptive, clinical evidence reflects their separate derivations from the mesenchyme of the first and
suggests that some of their fibres are motor. second branchial arches.
Actions Acting alone, each sternocleidomastoid will tilt the head Actions Digastric depresses the mandible and can elevate the hyoid
towards the ipsilateral shoulder, simultaneously rotating the head so as bone. The posterior bellies are especially active during swallowing and
to turn the face towards the opposite side. This movement occurs in an chewing.
upward, sideways glance. A more common visual movement is a level
rotation from side to side, and this probably represents the most fre Stylohyoid
quent use of the sternocleidomastoids. Acting together from below, the Stylohyoid arises by a small tendon from the posterior surface of the
muscles draw the head forwards and so help longi colli to flex the cervi styloid process, near its base. Passing downwards and forwards, it inserts
cal part of the vertebral column, which is a common movement in into the body of the hyoid bone at its junction with the greater cornu
feeding. The two sternocleidomastoids are also used to raise the head (and just above the attachment of the superior belly of omohyoid). It
when the body is supine; when the head is fixed, they help to elevate is perforated near its insertion by the intermediate tendon of digastric
the thorax in forced inspiration. (see Fig. 29.5). The muscle may be absent or double. It may lie medial
to the external carotid artery and may end in the suprahyoid or infra
Branchial cysts and fistulae Branchial cysts usually present in the hyoid muscles.
upper neck in early adulthood as fluctuant swellings at the junction of
the upper and middle thirds of the anterior border of sternocleidomas Vascular supply Stylohyoid receives its blood supply from branches
toid. The cyst typically passes backwards and upwards through the of the facial, posterior auricular and occipital arteries.


carotid bifurcation and ends at the pharyngeal constrictor muscles, a
course that brings it into intimate association with the hypoglossal, Innervation Stylohyoid is innervated by the stylohyoid branch of the
glossopharyngeal and accessory nerves. Great care must be taken to facial nerve, which frequently arises with the digastric branch, and
avoid damage to these nerves during surgical removal of a branchial enters the middle part of the muscle.
cyst.
Branchial fistulae represent a persistent connection between the Actions Stylohyoid elevates the hyoid bone and draws it backwards,
second branchial pouch and the cervical sinus (Commentary 2.2). The elongating the floor of the mouth.
fistula typically presents as a small pit adjacent to the anterior border
of the lower third of sternocleidomastoid, which may weep saliva and Stylohyoid ligament
become intermittently infected. Excision involves following the tract of The stylohyoid ligament is a fibrous cord extending from the tip of the
the fistula up the neck – often through the carotid bifurcation – and styloid process to the lesser cornu of the hyoid bone. It gives attachment
into the distal tonsillar fossa, where it opens into the pharynx. to the highest fibres of the middle pharyngeal constrictor and is inti
Branchial cysts, sinuses and fistulae are thought to arise from inclu mately related to the lateral wall of the oropharynx. Below, it is over
sions of salivary gland tissue in lymph nodes; they may also develop lapped by hyoglossus. The ligament is derived from the cartilage of the
around the parotid gland. second branchial arch, and may be partially calcified.
MUSCLES OF THE ANTERIOR TRIANGLE INFRAHYOID MUSCLES
OF THE NECK
The infrahyoid muscles are organized so that sternohyoid and omo
Apart from the superficial neck muscles already described, the anterior hyoid lie superficially, and sternothyroid and thyrohyoid lie more
triangle contains two of the suprahyoid muscles – namely, digastric and deeply (see Fig. 29.5). The muscles are involved in movements of the


stylohyoid – and the four infrahyoid strap muscles (see Fig. 29.5). The hyoid bone and thyroid cartilage during vocalization, swallowing and
other suprahyoid muscles, namely mylohyoid and geniohyoid, are mastication, and are mainly innervated from the ansa cervicalis.
described with the floor of the mouth on page 509.
Sternohyoid
Digastric
Sternohyoid is a thin, narrow strap muscle that arises from the posterior
Digastric has two bellies and lies below the mandible, extending from surface of the medial end of the clavicle, the posterior sternoclavicular
the mastoid process to the chin (see Fig. 29.5). The posterior belly, ligament and the upper posterior aspect of the manubrium (see Fig.
which is longer than the anterior, is attached in the mastoid notch of 29.5). It ascends medially and is attached to the inferior border of the
the temporal bone, and passes downwards and forwards. The anterior body of the hyoid bone. Inferiorly, there is a considerable gap between
belly is attached to the digastric fossa on the base of the mandible near the muscle and its contralateral fellow, but the two usually come
the midline, and slopes downwards and backwards. The two bellies together in the middle of their course and are contiguous above this.
meet in an intermediate tendon that perforates stylohyoid and runs in Sternohyoid may be absent or double, augmented by a clavicular slip
a fibrous sling attached to the body and greater cornu of the hyoid bone; (cleidohyoid), or interrupted by a tendinous intersection.
it is sometimes lined by a synovial sheath. The two bellies of digastric
mark out the borders of the submandibular triangle. Vascular supply Sternohyoid is supplied by branches from the su
perior thyroid artery.
Variations Digastric may lack the intermediate tendon and is then
attached midway along the body of the mandible. The posterior belly Innervation Sternohyoid is innervated by branches from the ansa
may be augmented by a slip from the styloid process or arise wholly cervicalis (C1, 2, 3).


from it. The anterior belly may cross the midline and it is not uncom
mon for it to fuse with mylohyoid. Actions Sternohyoid depresses the hyoid bone after it has been
elevated.
Relations Superficial to digastric are platysma, sternocleidomastoid,
Omohyoid
splenius capitis, longissimus capitis and stylohyoid, the mastoid
process, the retromandibular vein, and the parotid and submandibular Omohyoid consists of two bellies united at an angle by an intermediate
salivary glands. Mylohyoid is medial to the anterior belly, and hyoglos tendon (see Fig. 29.5). The inferior belly is a flat, narrow band, which
sus, superior oblique and rectus capitis lateralis, the transverse process inclines forwards and slightly upwards across the lower part of the neck.
of the atlas vertebra, the accessory nerve, internal jugular vein, occipital It arises from the upper border of the scapula, near the scapular notch,
artery, hypoglossal nerve, internal and external carotid, facial and and occasionally from the superior transverse scapular ligament. It then
lingual arteries are all medial to the posterior belly. passes behind sternocleidomastoid and ends there in the intermediate
tendon. The superior belly begins at the intermediate tendon, passes
Vascular supply The posterior belly is supplied by the posterior almost vertically upwards near the lateral border of sternohyoid, and is
auricular and occipital arteries. The anterior belly of digastric receives attached to the lower border of the body of the hyoid bone lateral to
its blood supply chiefly from the submental branch of the facial artery. the insertion of sternohyoid. The length and form of the intermediate
tendon vary, although it usually lies adjacent to the internal jugular vein
Innervation The anterior belly of digastric is supplied by the mylo at the level of the arch of the cricoid cartilage. The angulated course of
hyoid branch of the inferior alveolar nerve, and the posterior belly is the muscle is maintained by a band of deep cervical fascia, attached


NECk
450
4
NOITCES
below to the clavicle and the first rib, which ensheathes the tendon. A
variable amount of skeletal muscle may be present in the fascial band;
either belly may be absent or double; and the inferior belly may be
attached directly to the clavicle and the superior is sometimes fused
with sternohyoid. Rectus capitis anterior Rectus capitis lateralis
Transverse process
Vascular supply Omohyoid is supplied by branches from the su Longus colli, of atlas
perior thyroid and lingual arteries. superior oblique part Longus capitis
Innervation The superior belly of omohyoid is innervated by branches Levator scapulae
from the superior ramus of the ansa cervicalis (C1). The inferior belly
is innervated from the ansa cervicalis itself (C1, 2 and 3).
Longus colli, vertical part
Actions Omohyoid depresses the hyoid bone after it has been ele
vated. It has been speculated that the muscle tenses the lower part of
the deep cervical fascia in prolonged inspiratory efforts, reducing the Scalenus medius
Longus colli,
tendency for soft parts to be sucked inwards. Scalenus anterior
inferior oblique part
Sternothyroid Scalenus medius Scalenus posterior
Sternothyroid is shorter and wider than sternohyoid, and lies deep and Scalenus
posterior
partly medial to it (see Fig. 29.5). It arises from the posterior surface of
the manubrium sterni inferior to the origin of sternohyoid and from
the posterior edge of the cartilage of the first rib. It is attached above to
the oblique line on the lamina of the thyroid cartilage, where it delin
eates the upward extent of the thyroid gland. In the lower part of the
neck, the muscle is in contact with its contralateral fellow, but the two First rib
diverge as they ascend.
Vascular supply Sternothyroid is supplied by branches from the
Fig. 29.6 The anterior and lateral vertebral muscles. Scalenus anterior
superior thyroid and lingual arteries.
and longus capitis have been removed on the right side.
Innervation Sternothyroid is innervated by branches from the ansa


cervicalis (C1, 2 and 3).
Actions Rectus capitis anterior flexes the head at the atlantooccipital
Actions Sternothyroid draws the larynx downwards after it has been joints.
elevated by swallowing or vocal movements. In the singing of low notes, Rectus capitis lateralis
this downward traction would be exerted with the hyoid bone relatively
Rectus capitis lateralis is a short, flat muscle that arises from the upper
fixed.
surface of the transverse process of the atlas and inserts into the inferior
surface of the jugular process of the occipital bone. In view of its attach
Thyrohyoid
ments and its relation to the ventral ramus of the first spinal nerve,
Thyrohyoid is a small, quadrilateral muscle that may be regarded as an
rectus capitis lateralis is regarded as homologous with the posterior
upward continuation of sternothyroid (see Fig. 29.5). It arises from the
intertransverse muscles.
oblique line on the lamina of the thyroid cartilage, and passes upwards
to attach to the lower border of the greater cornu and adjacent part of Vascular supply Rectus capitis lateralis is supplied by branches from
the body of the hyoid bone.
the vertebral, occipital and ascending pharyngeal arteries.
Vascular supply Thyrohyoid is supplied by branches from the su Innervation Rectus capitis lateralis is innervated by branches from the
perior thyroid and lingual arteries.
loop between the ventral rami of the first and second cervical spinal
nerves.
Innervation Unlike the other infrahyoid muscles, thyrohyoid is not
innervated by the ansa cervicalis. In common with geniohyoid, it is Actions Rectus capitis lateralis flexes the head laterally to the same
supplied by fibres from the first cervical spinal nerve that branch off
side.
from the hypoglossal nerve beyond the descendens hypoglossi.
Longus capitis
Actions Thyrohyoid depresses the hyoid bone. With the hyoid Longus capitis (see Fig. 29.6) has a narrow origin from tendinous slips


bone stabilized, it pulls the larynx upwards, e.g. when high notes are from the anterior tubercles of the transverse processes of the third,
sung. fourth, fifth and sixth cervical vertebrae, and becomes broad and thick
above, where it is inserted into the inferior surface of the basilar part
of the occipital bone.
ANTERIOR VERTEBRAL MUSCLES
Vascular supply Longus capitis is supplied by the ascending pha
The anterior vertebral group of muscles are longi colli and capitis, and ryngeal, ascending cervical branch of the inferior thyroid and the ver
recti capitis anterior and lateralis (Fig. 29.6), all of which are flexors of tebral arteries.
the head and neck to varying degrees. Together with the lateral vertebral
muscles, they form the prevertebral muscle group. Innervation Longus capitis is innervated by branches from the ventral
rami of the first, second and third cervical spinal nerves.
Rectus capitis anterior
Rectus capitis anterior is a short, flat muscle situated behind the upper Actions Longus capitis flexes the head.
part of longus capitis. It arises from the anterior surface of the lateral
Longus colli
mass of the atlas and the root of its transverse process, and ascends
almost vertically to the inferior surface of the basilar part of the occipital Longus colli (see Fig. 29.6) is applied to the anterior surface of the
bone immediately anterior to the occipital condyle. vertebral column, between the atlas and the third thoracic vertebra. It
can be divided into three parts, which all arise by tendinous slips. The
Vascular supply Rectus capitis anterior is supplied by branches from inferior oblique part is the smallest, running upwards and laterally from
the vertebral and ascending pharyngeal arteries. the anterior surfaces of the bodies of the first two or three thoracic
vertebrae to the anterior tubercles of the transverse processes of the fifth
Innervation Rectus capitis anterior is innervated by branches from the and sixth cervical vertebrae. The superior oblique part passes upwards
loop between the ventral rami of the first and second cervical spinal and medially from the anterior tubercles of the transverse processes of


nerves. the third, fourth and fifth cervical vertebrae, to be attached by a narrow


Vascular supply and lymphatic drainage
451
92
RETPAHC
tendon to the anterolateral surface of the tubercle on the anterior arch and scalenus posterior lie posterolateral to it. The upper two roots of
of the atlas. The vertical intermediate part ascends from the anterior the nerve to serratus anterior and the dorsal scapular nerve (to the
surfaces of the bodies of the upper three thoracic and lower three cervi rhomboids) pierce the muscle and appear on its lateral surface.
cal vertebrae to the fronts of the bodies of the second, third and fourth
cervical vertebrae. Innervation Scalenus medius is supplied by branches from the ventral
rami of the third to eighth cervical spinal nerves.
Vascular supply Longus colli is supplied by branches from the ver
tebral, inferior thyroid and ascending pharyngeal arteries. Actions Acting from below, scalenus medius bends the cervical part
of the vertebral column to the same side. Acting from above, it helps to
Innervation Longus colli is innervated by branches from the ventral raise the first rib. The scalene muscles, particularly scalenus medius, are
rami of the second, third, fourth, fifth and sixth cervical spinal nerves. active during inspiration, even during quiet breathing in the erect
attitude.
Actions Longus colli flexes the neck forwards. In addition, the oblique
Scalenus posterior
parts may flex it laterally, and the inferior oblique part rotates it to the
Scalenus posterior is the smallest and most deeply situated of the
opposite side. Its main antagonist is longissimus cervicis.
scalene muscles (see Fig. 29.6). It passes from the posterior tubercles of
the transverse processes of the fourth, fifth and sixth cervical vertebrae
LATERAL VERTEBRAL MUSCLES to the outer surface of the second rib, behind the tubercle for serratus
anterior, where it is attached by a thin tendon.
Scalenus posterior is occasionally blended with scalenus medius.
Scaleni anterior, medius and posterior extend obliquely between the
The scalene muscles vary a little in the number of vertebrae to which
upper two ribs and the cervical transverse processes. Scalenus minimus


they are attached, in their degree of separation and in their segmental
(pleuralis) is associated with the suprapleural membrane and cervical
innervation.
pleura, and is described on page 954.
Scalenus anterior Vascular supply All the scalene muscles are chiefly supplied by the
ascending cervical branch of the inferior thyroid artery. Scalenus pos
Scalenus anterior lies at the side of the neck deep (posteromedial) to
terior receives an additional supply from the superficial cervical artery.
sternocleidomastoid (see Figs 29.5, 29.18). Above, it is attached by
musculotendinous fascicles to the anterior tubercles of the transverse
Innervation Scalenus posterior is innervated by branches from the
processes of the third, fourth, fifth and sixth cervical vertebrae. These
ventral rami of the lower three cervical spinal nerves.
converge, blend and descend almost vertically, to be attached by a
narrow, flat tendon to the scalene tubercle on the inner border of the
Actions When the second rib is fixed, scalenus posterior bends the
first rib, and to a ridge on the upper surface of the rib anterior to the
lower end of the cervical part of the vertebral column to the same side.
groove for the subclavian artery (see Fig. 29.6).
When its upper attachment is fixed, it helps to elevate the second rib.
Relations Scalenus anterior forms an important landmark in the root
of the neck because the phrenic nerve passes anterior to it and the
POSTERIOR VERTEBRAL MUSCLES
subclavian artery posterior to it; the brachial plexus lies at its lateral
border. The clavicle, subclavius, sternocleidomastoid and omohyoid,
Splenius capitis and splenius cervicis are described in Chapter 43.
lateral part of the carotid sheath, transverse cervical, suprascapular and
ascending cervical arteries, subclavian vein, prevertebral fascia and
phrenic nerve are all anterior to scalenus anterior. Posteriorly are the VASCULAR SUPPLY AND LYMPHATIC DRAINAGE
suprapleural membrane, pleura, roots of the brachial plexus and the


subclavian artery; the latter two separate scalenus anterior from scalenus
ARTERIES OF THE NECK
medius. The proximity of the muscle to the brachial plexus and sub
clavian artery and vein can give rise to compression syndromes. Below
The common carotid, internal carotid and external carotid arteries
its attachment to the sixth cervical vertebra, the medial border of the
provide the major source of blood to the head and neck (Figs 29.7A,
muscle is separated from longus colli by an angular interval in which
29.8). Additional arteries arise from branches of the subclavian artery,
the vertebral artery and vein pass to and from the foramen transvers
particularly the vertebral artery.
arium of the sixth cervical vertebra. The inferior thyroid artery crosses
The common, internal and external carotid arteries and accompany
this interval from the lateral to the medial side near its apex. The sym
ing veins and nerves all lie in a cleft that is bound posteriorly by the
pathetic trunk and its cervicothoracic ganglion are closely related to the
transverse processes of cervical vertebrae and attached muscles, medi
posteromedial side of this part of the vertebral artery. On the left side,
ally by the trachea, oesophagus, thyroid gland, larynx and pharyngeal
the thoracic duct crosses the triangular interval at the level of the seventh
constrictors, and anterolaterally by sternocleidomastoid and, at differ
cervical vertebra and usually comes into contact with the medial edge
ent levels, omohyoid, sternohyoid, sternothyroid, digastric and stylo
of scalenus anterior. The musculotendinous attachments of scalenus
hyoid muscles. The common and internal carotid arteries lie within the
anterior to anterior tubercles are separated from those of longus capitis
carotid sheath, accompanied by the internal jugular vein and the vagus
by the ascending cervical branch of the inferior thyroid artery.
nerve.
Innervation Scalenus anterior is innervated by branches from the
Common carotid artery
ventral rami of the fourth, fifth and sixth cervical spinal nerves.
Actions Acting from below, scalenus anterior bends the cervical The common carotid arteries differ on the right and left sides with


portion of the vertebral column forwards and laterally, and rotates it respect to their origins. On the right, the common carotid arises from
towards the opposite side. Acting from above, the muscle helps to the brachiocephalic artery as it passes behind the sternoclavicular joint.
elevate the first rib. On the left, the common carotid artery comes directly from the arch of
the aorta in the superior mediastinum. The right common carotid,
Scalenus medius
therefore, has only a cervical part whereas the left common carotid has
Scalenus medius, the largest and longest of the scaleni, is attached above cervical and thoracic parts. Following a similar course on both sides,
to the transverse process of the axis and the anterior surface of the the common carotid artery ascends, diverging laterally from behind the
posterior tubercles of the transverse processes of the lower five cervical sternoclavicular joint to the level of the upper border of the thyroid
vertebrae (see Fig. 29.6). It frequently extends upwards to the transverse cartilage of the larynx (C3–4 junction), where it divides into external
process of the atlas. Below it is attached to the upper surface of the first and internal carotid arteries. This bifurcation can sometimes be at a
rib between the tubercle of the rib and the groove for the subclavian higher or lower level (see Fig. 29.7B). The angle of bifurcation remains
artery. unchanged from infancy to adulthood. However, there is a significant
change in the angle of the split between the internal and the external
Relations The anterolateral surface of the muscle is related to sterno carotid arteries relative to the common carotid artery (Seong et al
cleidomastoid (see Fig. 29.5). It is crossed anteriorly by the clavicle and 2005). The artery may be compressed against the prominent transverse
omohyoid, and it is separated from scalenus anterior by the subclavian process of the sixth cervical vertebra (Chassaignac’s tubercle); above this
artery and ventral rami of the cervical spinal nerves. Levator scapulae level it is superficial and its pulsation can be easily felt.


NECk
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4
NOITCES
A
Retromandibular vein
Hypoglossal nerve
Internal jugular vein
Facial artery
Submental artery
Occipital artery
External carotid artery
Superior laryngeal nerve
Internal carotid artery
Superior laryngeal artery
Accessory nerve
Superior thyroid artery
Vagus nerve
Common carotid artery
Ansa cervicalis
Suprascapular artery
Inferior thyroid artery
Ascending cervical artery
Vertebral artery
Phrenic nerve
Thyrocervical trunk
Internal jugular vein
External jugular vein
B
C1
Fig. 29.7 A, Vessels and nerves of the neck, left lateral
C2 view. Sternocleidomastoid and the greater part of
omohyoid and the internal jugular vein have been
C3
removed. Compare with Figure 29.17, which shows a
C4
deeper level of dissection. B, The variation in levels of
C5 bifurcation of the common carotid artery, related to the
C6 cervical vertebrae. (A and B, With permission from
Waschke J, Paulsen F (eds), Sobotta Atlas of Human
C7
Anatomy, 15th ed, Elsevier, Urban & Fischer. Copyright
<1% 4% 12% 30% 35% 12% 5% 1% 2013.)
Relations In the lower part of the neck, the common carotid arteries carotid sheath are the transverse processes of the fourth to sixth cervical
are separated by a narrow gap that contains the trachea. Above this, the vertebrae, to which are attached longus colli, longus capitis and ten
arteries are separated by the thyroid gland, larynx and pharynx. Each dinous slips of scalenus anterior. The sympathetic trunk and ascending
artery is contained within the carotid sheath of deep cervical fascia, cervical branch of the inferior thyroid artery lie between the common
which also encloses the internal jugular vein and vagus nerve. The vein carotid artery and the muscles. Below the level of the sixth cervical
lies lateral to the artery, and the nerve lies between them and posterior vertebra, the artery is in an angle between scalenus anterior and longus


to both. colli, anterior to the vertebral vessels, inferior thyroid and subclavian
The artery is crossed anterolaterally, at the level of the cricoid carti arteries, sympathetic trunk and, on the left, the thoracic duct. The
lage, by the intermediate tendon – sometimes the superior belly – of oesophagus, trachea, inferior thyroid artery, recurrent laryngeal nerve
omohyoid. Below omohyoid, it is sited deeply, and covered by skin, and, at a higher level, the larynx and pharynx are medial to the sheath
superficial fascia, platysma, deep cervical fascia, and sternocleidomas and its contents. The thyroid gland overlaps it anteromedially. The
toid, sternohyoid and sternothyroid. Above omohyoid, it is more super internal jugular vein lies lateral and, in the lower neck, also anterior to
ficial, and covered merely by skin, superficial fascia, platysma, deep the artery, while the vagus nerve lies posterolaterally in the angle
cervical fascia and the medial margin of sternocleidomastoid; it is between artery and vein.
crossed obliquely from its medial to lateral side by the sternocleido On the right side, low in the neck, the recurrent laryngeal nerve
mastoid branch of the superior thyroid artery. The superior root of the crosses obliquely behind the artery. The right internal jugular vein
ansa cervicalis, joined by its inferior root from the second and third diverges from it below but the left vein approaches and often overlaps
cervical spinal nerves, lies anterior to, or embedded within, the carotid its artery.
sheath as it crosses it obliquely. The superior thyroid vein usually The right common carotid artery sometimes arises above the level
crosses near the upper border of the thyroid cartilage, and the middle of the sternoclavicular joint, or it may be a separate branch from
thyroid vein crosses a little below the level of the cricoid cartilage. The the aorta. The left common carotid artery varies in origin more than the
anterior jugular vein crosses the common carotid artery above the clavi right and may arise with the brachiocephalic artery. Division of the


cle, separated from it by sternohyoid and sternothyroid. Posterior to the common carotid may occur higher, near the level of the hyoid bone, or,


Vascular supply and lymphatic drainage
453
92
RETPAHC
medial to the facial nerve and the junction of the superficial temporal
Superficial temporal artery Styloid process and maxillary veins. The pharyngeal wall, superior laryngeal nerve and
Ascending pharyngeal artery ascending pharyngeal artery are the initial medial relations of the
Accessory nerve
Maxillary artery artery. At a higher level, it is separated from the internal carotid artery
Pharyngeal
by the styloid process, styloglossus and stylopharyngeus, glossopharyn
External carotid artery branch of vagus
geal nerve, pharyngeal branch of vagus nerve and part of the parotid
Stylopharyngeus Superior gland. The artery is equally likely to lie medial to the parotid gland, or
laryngeal nerve
within it.
Glossopharyngeal nerve
Digastric, The external carotid artery has eight named branches distributed to
posterior belly the head and neck. The superior thyroid, lingual and facial arteries arise
from its anterior surface, the occipital and posterior auricular arteries
Internal carotid artery
arise from its posterior surface, and the ascending pharyngeal artery
Posterior auricular artery Upper arises from its medial surface. The maxillary and superficial temporal
sternocleidomastoid arteries are its terminal branches within the parotid gland.
Facial artery branch of occipital artery
Superior thyroid artery
The superior thyroid artery is the first branch of the external carotid
Occipital artery
Hypoglossal nerve artery, and arises from the anterior surface of the external carotid just
Vagus nerve below the level of the greater cornu of the hyoid bone (see Figs 29.7A,
Lingual artery 29.8). It descends along the lateral border of thyrohyoid to reach the
Lower apex of the lobe of the thyroid gland. Lying medially are the inferior
Internal laryngeal nerve sternocleidomastoid constrictor muscle and the external laryngeal nerve; the nerve is often
branch of occipital artery
Superior thyroid artery posteromedial, and therefore at risk when the artery is being ligated.
External laryngeal nerve Occasionally, it may issue directly from the common carotid.
Inferior root of


ansa cervicalis Branches
The superior thyroid artery supplies the thyroid gland and some adja
Superior root of ansa cervicalis cent skin. Glandular branches are: anterior, which runs along the
medial side of the upper pole of the lateral lobe to supply mainly the
Ansa cervicalis Internal jugular vein anterior surface; a branch that crosses above the isthmus to anastomose
Common carotid artery with its fellow of the opposite side; and posterior, which descends on
the posterior border to supply the medial and lateral surfaces, and
anastomoses with the inferior thyroid artery. Sometimes, a lateral
Fig. 29.8 The branches of the external carotid artery. Note the structures
branch supplies the lateral surface. The artery also has the following
that either cross the internal jugular vein and the carotid arteries or
named branches: infrahyoid, superior laryngeal, sternocleidomastoid
intervene between the external and internal carotid arteries.
and cricothyroid.
Infrahyoid artery The infrahyoid artery is a small branch that runs
more rarely, at a lower level alongside the larynx. Very rarely, it ascends
along the lower border of the hyoid bone deep to thyrohyoid and
without division, so that either the external or internal carotid is absent,
anastomoses with its fellow of the opposite side to supply the infra
or it may be replaced by separate external and internal carotid arteries
hyoid strap muscles.
that arise directly from the aorta, on one side, or bilaterally.
Although the common carotid artery usually has no branches, it may Superior laryngeal artery The superior laryngeal artery accompa
occasionally give rise to the vertebral, superior thyroid, superior laryn
nies the internal laryngeal nerve. Deep to thyrohyoid, it pierces the
geal, ascending pharyngeal, inferior thyroid or occipital arteries.
lower part of the thyrohyoid membrane to supply the tissues of the
upper part of the larynx. It anastomoses with its fellow of the opposite
External carotid artery
side and with the inferior laryngeal branch of the inferior thyroid
artery.
The external carotid artery (see Figs 29.7A, 29.8) begins lateral to the


upper border of the thyroid cartilage, level with the intervertebral disc Sternocleidomastoid artery The sternocleidomastoid artery
between the third and fourth cervical vertebrae. A little curved and with descends laterally across the carotid sheath and supplies the middle
a gentle spiral, it first ascends slightly forwards and then inclines back region of sternocleidomastoid. Like the parent artery itself, it may arise
wards and a little laterally, to pass midway between the tip of the directly from the external carotid artery.
mastoid process and the angle of the mandible. Here, in the substance
of the parotid gland behind the neck of the mandible, it divides into Cricothyroid artery The cricothyroid artery crosses high on the
its terminal branches, the superficial temporal and maxillary arteries. anterior cricothyroid ligament, anastomoses with its fellow of the oppo
As it ascends, it gives off several large branches and diminishes rapidly site side and supplies cricothyroid.
in calibre. In children the external carotid is smaller than the internal
carotid, but in adults the two are of almost equal size. At its origin, it Ascending pharyngeal artery
is in the carotid triangle and lies anteromedial to the internal carotid The ascending pharyngeal artery is the smallest branch of the external
artery. It later becomes anterior, then lateral, to the internal carotid as carotid. It is a long, slender vessel, which arises from the medial (deep)
it ascends. At mandibular levels, the styloid process and its attached surface of the external carotid artery near the origin of that artery. It
structures intervene between the vessels; the internal carotid is deep, ascends between the internal carotid artery and the pharynx to the base
and the external carotid superficial, to the styloid process. A fingertip of the cranium. The ascending pharyngeal artery is crossed by styloglos
placed in the carotid triangle perceives a powerful arterial pulsation, sus and stylopharyngeus, and longus capitis lies posterior to it. It gives
which represents the termination of the common carotid, the origins off numerous small branches to supply longus capitis and longus colli,


of external and internal carotids, and the stems of the initial branches the sympathetic trunk, the hypoglossal, glossopharyngeal and vagus
of the external carotid. nerves, and some of the cervical lymph nodes. It anastomoses with the
ascending palatine branch of the facial artery and the ascending cervical
Relations The skin and superficial fascia, the loop between the cervi branch of the vertebral artery. Its named branches are the pharyngeal,
cal branch of the facial nerve and the transverse cutaneous nerve of the inferior tympanic and meningeal arteries.
neck, the deep cervical fascia and the anterior margin of sternocleido
mastoid all lie superficial to the external carotid artery in the carotid Pharyngeal artery The pharyngeal artery gives off three or four
triangle. The artery is crossed by the hypoglossal nerve and its vena branches to supply the constrictor muscles of the pharynx and stylo
comitans, and by the lingual, facial and, sometimes, the superior pharyngeus. A variable ramus supplies the palate, and may replace the
thyroid veins. Leaving the carotid triangle, the external carotid artery is ascending palatine branch of the facial artery. The artery descends for
crossed by the posterior belly of digastric and by stylohyoid, and wards between the superior border of the superior constrictor and
ascends between these muscles and the posteromedial surface of the levator veli palatini to the soft palate, and also supplies a branch to the
parotid gland, which it next enters. Within the parotid, the artery lies palatine tonsil and the pharyngotympanic tube.


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NOITCES
Inferior tympanic artery The inferior tympanic artery is a small Ascending palatine artery The ascending palatine artery arises
branch that traverses the temporal canaliculus with the tympanic close to the origin of the facial artery. It passes up between styloglossus
branch of the glossopharyngeal nerve and supplies the medial wall of and stylopharyngeus to reach the side of the pharynx, along which it
the tympanic cavity. ascends between the superior constrictor of the pharynx and medial
pterygoid towards the cranial base. It bifurcates near levator veli pal
Meningeal branches The meningeal branches are small vessels that atini. One branch follows this muscle, winding over the upper border
supply the nerves that traverse the foramen lacerum, jugular foramen of the superior constrictor of the pharynx to supply the soft palate and
and hypoglossal canal, and the associated dura mater and adjoining to anastomose with its fellow of the opposite side and the greater pala
bone. One branch, the posterior meningeal artery, reaches the cerebellar tine branch of the maxillary artery. The other branch pierces the su
fossa via the jugular foramen, and is usually regarded as the terminal perior constrictor muscle to supply the tonsil and pharyngotympanic
branch of the ascending pharyngeal artery. tube, and to anastomose with the tonsillar and ascending pharyngeal
arteries (see Fig. 34.7).
Lingual artery
The lingual artery provides the chief blood supply to the tongue and Tonsillar artery The tonsillar artery provides the main blood supply
the floor of the mouth (see Figs 29.8, 31.8). It arises anteromedially
to the palatine tonsil. It ascends between medial pterygoid and sty
from the external carotid artery opposite the tip of the greater cornu of
loglossus, penetrates the superior constrictor of the pharynx at the
the hyoid bone, between the superior thyroid and facial arteries. It often
upper border of styloglossus, and enters the inferior pole of the tonsil.
arises with the facial or, less often, with the superior thyroid artery. It


Its branches ramify in the tonsil and in the musculature of the posterior
may be replaced by a ramus of the maxillary artery. Ascending medially
part of the tongue. The tonsillar artery may sometimes arise from the
at first, it loops down and forwards, passes medial to the posterior
ascending palatine artery.
border of hyoglossus and then runs horizontally forwards deep to it.
The lingual artery next ascends again almost vertically, and courses sinu
Submental artery The submental artery is the largest cervical
ously forwards on the inferior surface of the tongue as far as its tip. The
branch of the facial artery (see Fig. 29.7). It arises as the facial artery
further course of the lingual artery is described on page 513.
separates from the submandibular gland and turns forwards on mylo
Relations Its relationship to hyoglossus naturally divides the lingual hyoid below the mandible. It supplies the overlying skin and muscles,
and anastomoses with a sublingual branch of the lingual and mylo
artery into descriptive ‘thirds’. In its first part, the lingual artery is in the
hyoid branch of the inferior alveolar artery. At the chin, it ascends over
carotid triangle. Skin, fascia and platysma are superficial to it, while the
the mandible, and divides into superficial and deep branches, which
middle pharyngeal constrictor muscle is medial. The artery ascends a
anastomose with the inferior labial and mental arteries to supply the
little medially, then descends to the level of the hyoid bone, and the
chin and lower lip.
loop so formed is crossed externally by the hypoglossal nerve. The
second part passes along the upper border of the hyoid bone, deep to
hyoglossus, the tendons of digastric and stylohyoid, the lower part of Glandular branches Three or four large vessels supply the sub
the submandibular gland and the posterior part of mylohyoid. Hyoglos mandibular salivary gland and associated lymph nodes, adjacent
sus separates it from the hypoglossal nerve and its vena comitans. Here, muscles and skin.
its medial aspect adjoins the middle constrictor muscle and it crosses
Occipital artery


the stylohyoid ligament accompanied by lingual veins. The third part
is the arteria profunda linguae, which turns upwards near the anterior The occipital artery arises posteriorly from the external carotid artery,
border of hyoglossus and then passes forwards close to the inferior approximately 2 cm from its origin (see Figs 29.7A, 29.8). At its origin,
lingual surface near the frenulum, accompanied by the lingual nerve. the artery is crossed superficially by the hypoglossal nerve, which winds
Genioglossus is a medial relation, and the inferior longitudinal muscle round it from behind. The artery next passes backwards, up and deep
of the tongue lies lateral to it below the lingual mucous membrane. to the posterior belly of digastric, and crosses the internal carotid artery,
Near the tip of the tongue, the lingual artery anastomoses with its fellow internal jugular vein, and hypoglossal, vagus and accessory nerves.
of the opposite side. Its named branches are the suprahyoid, dorsal Between the transverse process of the atlas and the mastoid process, the
lingual and sublingual arteries. occipital artery reaches the lateral border of rectus capitis lateralis. It
then runs in the occipital groove of the temporal bone, medial to the
Suprahyoid artery
mastoid process and attachments of sternocleidomastoid, splenius
The suprahyoid artery is a small branch that runs along the upper capitis, longissimus capitis and digastric, and lies successively on rectus
border of the hyoid bone to anastomose with the contralateral artery. capitis lateralis, obliquus superior and semispinalis capitis. Finally,
It supplies adjacent structures. accompanied by the greater occipital nerve, it turns upwards to pierce
the investing layer of the deep cervical fascia connecting the cranial
Dorsal lingual arteries
attachments of trapezius and sternocleidomastoid, and ascends tortu
The dorsal lingual arteries are described on page 513.
ously in the dense superficial fascia of the scalp, where it divides into
Sublingual artery many branches (see Fig. 43.76).
The occipital artery has two main branches (upper and lower) to the


The sublingual artery is described on page 513.
upper part of sternocleidomastoid in the neck. The lower branch arises
Facial artery near the origin of the occipital artery, and may sometimes arise directly
The facial artery (see Figs 29.7, 29.8, 30.25) arises anteriorly from the from the external carotid artery. It descends backwards over the
external carotid in the carotid triangle, above the lingual artery and hypoglossal nerve and internal jugular vein, enters sternocleidomastoid
immediately above the greater cornu of the hyoid bone. In the neck, at and anastomoses with the sternocleidomastoid branch of the superior
its origin, it is covered only by the skin, platysma, fasciae and often by thyroid artery. The upper branch arises as the occipital artery crosses the
the hypoglossal nerve. It runs up and forwards, deep to digastric and accessory nerve, and runs down and backwards superficial to the intern
stylohyoid. At first on the middle pharyngeal constrictor, it may reach al jugular vein. It enters the deep surface of sternocleidomastoid with
the lateral surface of styloglossus, separated there from the palatine the accessory nerve.
tonsil only by this muscle and the lingual fibres of the superior constric
Posterior auricular artery
tor. Medial to the mandibular ramus, it arches upwards and grooves the
posterior aspect of the submandibular gland. It then turns down and The posterior auricular artery is a small vessel that branches posteriorly
descends to the lower border of the mandible in a lateral groove on the from the external carotid just above digastric and stylohyoid. It ascends
submandibular gland, between the gland and medial pterygoid. Reach between the parotid gland and the styloid process to the groove between
ing the surface of the mandible, the facial artery curves round its inferior the auricular cartilage and mastoid process, and divides into auricular
border, anterior to masseter, to enter the face; its further course is and occipital branches, which are described with the face on page 499.


described on page 498. The artery is very sinuous throughout its extent. In the neck, it provides branches to supply digastric, stylohyoid, sterno
In the neck, this may be so that the artery is able to adapt to the move cleidomastoid and the parotid gland. It also gives origin to the stylo
ments of the pharynx during deglutition, and similarly on the face, so mastoid artery – described as an indirect branch of the posterior
that the artery can adapt to movements of the mandible, lips and auricular artery in about a third of subjects – which enters the stylo
cheeks. Facial artery pulsation is most palpable where the artery crosses mastoid foramen to supply the facial nerve, tympanic cavity, mastoid
the mandibular base, and again near the corner of the mouth. Its antrum air cells and semicircular canals. In the young, its posterior
branches in the neck are the ascending palatine, tonsillar, submental tympanic ramus forms a circular anastomosis with the anterior tym
and glandular arteries. panic branch of the maxillary artery.


Vascular supply and lymphatic drainage
455
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RETPAHC
Fig. 29.9 Internal carotid artery accessory and hypoglossal nerves lies between the internal carotid artery
anatomy shown on volume and the internal jugular vein, which here has become posterior. The
rendering of a computed length of the artery varies with the length of the neck and the point of
tomographic angiogram. The the carotid bifurcation. It may arise from the aortic arch, in which case
cervical internal carotid artery it lies medial to the external carotid as far as the larynx, where it crosses
(white arrow) is a branchless behind it. The cervical portion is normally straight but may be very
vessel. Note the course of the tortuous, when it lies closer to the pharynx than usual, very near the
vertebral artery (black arrow). (With
tonsil. In children, the tonsillocarotid distance increases with growth to
permission from Kaufman JA, and
a maximum value of 25 mm (Deutsch et al 1995). The internal carotid
Lee MJ, Carotid and vertebral
artery enters the cranium without giving off any branches. It may occa
arteries. In: Kaufman JA, Vascular
sionally be absent.
and Interventional Radiology: The
Occlusive atherosclerotic disease within either the internal carotid
Requisites, Chapter 5, 99–118.
or common carotid artery may cause strokes or transient ischaemic
Saunders.)
attacks (TIAs) characterized by weakness of the contralateral side. It may
also result in visual disturbances characterized classically as a ‘curtain’
falling down over the visual field (amaurosis fugax). These episodes will
be experienced in the ipsilateral eye.
Carotid sinus and carotid body
The common carotid artery has two specialized organs near its bifur
cation: the carotid sinus and the carotid body. They relay information
concerning the pressure and chemical composition of the arterial
blood, respectively, and are innervated principally by the carotid
branch(es) of the glossopharyngeal nerve, with small contributions
from the cervical sympathetic trunk and the vagus nerve.
The carotid sinus usually appears as a dilation of the lower end of


the internal carotid in late adolescence (Seong et al 2005) and functions
as a baroreceptor.
The carotid body is a reddishbrown, oval structure, 5–7 mm in
height and 2.5–4 mm in width. It lies either posterior to the carotid
bifurcation or between its branches, and is attached to, or sometimes
partly embedded in, their adventitia. Occasionally, it takes the form of
a group of separate nodules. Aberrant miniature carotid bodies, micro
structurally similar but with diameters of 600 µm or less, may appear
in the adventitia and adipose tissue near the carotid sinus.
The carotid body is surrounded by a fibrous capsule, from which
septa divide the enclosed tissue into lobules. Each lobule contains
glomus (type I) cells, which are separated from an extensive network
of fenestrated sinusoids by sustentacular (type II) cells (Fig. 29.10).
Glomus cells store a number of peptides, particularly enkephalins,
bombesin and neurotensin, and amines including dopamine, sero
tonin (5hydroxytryptamine, 5HT), adrenaline (epinephrine) and
Internal carotid artery
noradrenaline (norepinephrine), and are therefore regarded as paraneu
rones. Unmyelinated axons lie in a collagenous matrix between the
The internal carotid artery supplies most of the ipsilateral cerebral sustentacular cells and the sinusoidal endothelium, and many synapse
hemisphere, eye and accessory organs, forehead and, in part, the nose. on the glomus cells. They are visceral afferents, which travel in the
From its origin at the carotid bifurcation (see Fig. 29.8; Fig. 29.9) carotid sinus nerve to join the glossopharyngeal nerve. Preganglionic
(where there is usually a carotid sinus), it ascends in front of the trans sympathetic axons and fibres from the carotid sinus synapse on para
verse processes of the upper three cervical vertebrae to the inferior sympathetic and sympathetic ganglion cells, which lie either in isola


aperture of the carotid canal in the petrous part of the temporal bone. tion or in small groups near the surface of each carotid body.
Here, it enters the cranial cavity and turns anteriorly through the cavern Postganglionic axons travel to local blood vessels; the parasympathetic
ous sinus in the carotid groove on the side of the body of the sphenoid efferent fibres are probably vasodilatory and the sympathetic ones are
bone. It terminates below the anterior perforated substance by division vasoconstrictor.
into the anterior and middle cerebral arteries. It may be divided con The carotid body receives a rich blood supply from branches of the
veniently into cervical, petrous, cavernous and cerebral parts. Rarely, adjacent external carotid artery, which is consistent with its role as an
persistent embryonic branches to the basilar artery from the cervical arterial chemoreceptor. When stimulated by hypoxia, hypercapnia or
part of the internal carotid artery may be encountered at the C1–C2 increased hydrogen ion concentration (low pH) in the blood flowing
(persistent hypoglossal artery) and C2–C3 (proatlantal intersegmental through it, it elicits reflex increases in the rate and volume of ventilation
artery) levels. via connections with brainstem respiratory centres. The bodies are most
prominent in children and normally involute in older age, when they
Relations The internal carotid artery is initially superficial in the are infiltrated by lymphocytes and fibrous tissue. Individuals with
carotid triangle, and then passes deeper, medial to the posterior belly chronic hypoxia, or who live at high altitude or suffer from lung disease,
of digastric. Except near the skull, the internal jugular vein and vagus may have enlarged carotid bodies as a result of hyperplasia. Disrupted
nerve are lateral to it within the carotid sheath. The external carotid carotid body maturation may play a role in sudden infant death syn
artery is first anteromedial, but then curves back to lie superficial. Pos drome (Porzionato et al 2013).
teriorly, the internal carotid adjoins longus capitis, and the superior Other small bodies, resembling carotid bodies and also considered


cervical sympathetic ganglion lies between them. The superior laryngeal to be chemoreceptors, are present near the arteries of the fourth and
nerve crosses obliquely behind it. The pharyngeal wall lies medial to sixth pharyngeal arches and hence are found near the aortic arch, liga
the artery, which is separated by fat and pharyngeal veins from the mentum arteriosum and right subclavian artery; they are supplied by
ascending pharyngeal artery and superior laryngeal nerve. Anterolateral ly, the vagus nerve.
the internal carotid artery is covered by sternocleidomastoid. Below the
posterior belly of digastric, the hypoglossal nerve and superior root of
Subclavian artery
the ansa cervicalis and the lingual and facial veins are superficial to the
artery. At the level of the digastric, the internal carotid is crossed by
stylohyoid and the occipital and posterior auricular arteries. Above the The right subclavian artery arises from the brachiocephalic trunk,
digastric, it is separated from the external carotid artery by the styloid the left from the aortic arch (see Figs 29.14, 29.18). For description,
process, styloglossus and stylopharyngeus, the glossopharyngeal nerve each is divided into a first part, from its origin to the medial border
and the pharyngeal branch of the vagus, and the deeper part of the of scalenus anterior; a second part behind this muscle; and a third
parotid gland. At the base of the skull, the glossopharyngeal, vagus, part from the lateral margin of scalenus anterior to the outer border


NECk
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4
NOITCES
Preganglionic parasympathetic axon Glossopharyngeal axons
Sinusoid
Sinusoid
Sinusoid
PSG
Type I, glomus cells
Type II, sustentacular (sheath) cells
Endothelium
Axons and ganglion cells
PSG Parasympathetic ganglion cell
Sinusoid SG Sympathetic ganglion cell
Preganglionic
sympathetic axon
Vasodilator route
Vasoconstrictor route
Chemoreceptor route
Arteriole
Efferent glomeral route
SG
Endocrine secretion
Synaptic transmission
Reciprocal synaptic transmission
Postganglionic
Presynaptic and axo-axonal transmission
Preganglionic sympathetic axon sympathetic axon
Fig. 29.10 The cellular, neural and vascular architecture of the carotid body. Functional pathways are indicated.
of the first rib, where the artery becomes the axillary artery. Each sub Relations The skin, superficial fascia, platysma, deep cervical fascia,
clavian artery arches over the cervical pleura and pulmonary apex. sternocleidomastoid and scalenus anterior are anterior. The right
Their first parts differ, whereas the second and third parts are almost phrenic nerve is often described as being separated from the second
identical. part of the subclavian artery by scalenus anterior, whereas it crosses the
first part of the left subclavian artery. However, both nerves may some
First part of right subclavian artery
times lie anterior to the muscle. The suprapleural membrane, pleura
The right subclavian artery branches from the brachiocephalic trunk and lung, and the lower trunk of the brachial plexus are posteroinferior;
behind the upper border of the right sternoclavicular joint, and passes the upper and middle trunks of the plexus are superior; and the sub
superolaterally to the medial margin of scalenus anterior. It usually clavian vein is anteroinferior, separated by scalenus anterior.
ascends 2 cm above the clavicle but this varies.
Third part of subclavian artery
Relations The artery is deep to the skin, superficial fascia, platysma, The third part of the subclavian artery descends laterally from the lateral


supraclavicular nerves, deep fascia, clavicular attachment of sternoclei margin of scalenus anterior to the outer border of the first rib, where it
domastoid, sternohyoid and sternothyroid. It is at first behind the becomes the axillary artery. It is the most superficial part of the artery
origin of the right common carotid artery; more laterally, it is crossed and lies partly in the supraclavicular triangle, where its pulsations may
by the vagus nerve, the cardiac branches of the vagus and the sympa be felt and it may be compressed. The third part of the subclavian artery
thetic chain, and by internal jugular and vertebral veins; the subclavian is the most accessible segment of the artery. Since the line of the pos
sympathetic loop encircles it. The anterior jugular vein diverges laterally terior border of sternocleidomastoid approximates to the (deeper)
in front of it, separated by sternohyoid and sternothyroid. Below and lateral border of scalenus anterior, the artery can be felt in the antero
behind the artery are the pleura and pulmonary apex; they are separated inferior angle of the posterior triangle. It can only be effectively com
from the artery by the suprapleural membrane, the ansa subclavia, a pressed against the first rib: with the shoulder depressed, pressure is
small accessory vertebral vein and the right recurrent laryngeal nerve, exerted down, back and medially in the angle between sternocleido
which winds round the lower and posterior part of the vessel. mastoid and the clavicle. The palpable trunks of the brachial plexus may
be injected with local anaesthetic allowing major surgical procedures
First part of left subclavian artery
to the arm.
The first part of the left subclavian artery springs from the aortic arch,
behind the left common carotid, level with the disc between the third Relations The skin, superficial fascia, platysma, supraclavicular nerves
and fourth thoracic vertebrae. It ascends into the neck, and then arches and deep cervical fascia are anterior. The external jugular vein crosses
laterally to the medial border of scalenus anterior. its medial end and here receives the suprascapular, transverse cervical
and anterior jugular veins, which collectively often form a venous


Relations In the neck, near the medial border of scalenus anterior, plexus. The nerve to subclavius descends between the veins and the
the artery is crossed anteriorly by the left phrenic nerve and the termin artery; the latter is terminally behind the clavicle and subclavius, where
ation of the thoracic duct. Otherwise, anterior relations are the same as it is crossed by the suprascapular vessels. The subclavian vein is antero
those of the first part of the right subclavian artery. Posteriorly and inferior and the lower trunk of the brachial plexus is posteroinferior,
inferiorly, the relations of both vessels are identical but the left recurrent between the subclavian artery and the scalenus medius (and on the first
laryngeal nerve, medial to the left subclavian artery in the thorax, is not rib). The upper and middle trunks of the brachial plexus (which are
directly related to its cervical part. palpable here) and the inferior belly of omohyoid are superolateral.
The first rib is inferior.
Second part of subclavian artery The right subclavian artery may arise above or below sternoclavicular
The second part of the subclavian artery lies behind scalenus anterior; level; it may be a separate aortic branch and be the first or last branch
it is short and constitutes the highest part of the vessel (see Fig. 29.18). of the arch. When it is the first branch, it is in the position of a


Vascular supply and lymphatic drainage
457
92
RETPAHC
Tentorium
cerebelli
Tentorial
Trochlear notch
nerve
Trigeminal nerve
Median
sulcus of
fourth Transverse dural
ventricle venous sinus
Facial and
vestibulocochlear
Hypoglossal nerves
nerve
Glossopharyngeal,
Posterior vagus and
spinal artery accessory nerves
Accessory nerve
Digastric,
posterior belly
Vertebral artery
Atlas,
transverse
process First cervical
(suboccipital) nerve
Accessory nerve Atlas, posterior arch
Second cervical
spinal ganglion Dura mater
Vagus nerve
Internal Third cervical dorsal
jugular vein ramus
Sternocleido-
mastoid Ligamentum denticulatum
Superior cervical
sympathetic
ganglion
Spinal accessory
nerve
Vagus nerve (displaced medially)
Common carotid artery Vertebral artery
Fig. 29.11 A dissection of the brainstem and the upper part of the spinal cord after removal of large portions of the occipital and parietal bones, the
cerebellum and the roof of the fourth ventricle. On the left side, the foramina transversaria of the atlas and the third, fourth and fifth cervical vertebrae
have been opened to expose the vertebral artery. On the right side, the posterior arch of the atlas and the laminae of the succeeding cervical vertebrae
have been divided and have been removed, together with the vertebral spines and the contralateral laminae. The tentorium cerebelli and the transverse
sinuses have been divided and their posterior portions removed.
brachiocephalic trunk. When it is the last branch, it arises from the left
Fig. 29.12 The level of
end of the arch, and ascends obliquely to the right behind the trachea,
C1 entry of the vertebral artery
oesophagus and right common carotid to the first rib. When this
into the foramina
happens, the right recurrent laryngeal nerve hooks round the common C2
transversaria of the cervical
carotid artery. Sometimes, when the right subclavian artery is the last


aortic branch, it passes between the trachea and oesophagus and can C3 1% v ee nr tt ee rb ara t e th. eN lo et ve e t l h oa ft t9 h0 e%
cause dysphagia, a condition known as dysphagia lusoria. It may per C4 sixth cervical vertebra.
2%
forate scalenus anterior, and very rarely may pass anterior to it. Some C5 (Redrawn with permission
times, the subclavian vein accompanies the artery behind scalenus 5% from Waschke J, Paulsen F
anterior. The artery may ascend as high as 4 cm above the clavicle or it C6 90% (eds), Sobotta Atlas of
may reach only its upper border. The left subclavian artery is occasion Human Anatomy, 15th ed,
C7
ally combined at its origin with the left common carotid artery. 2% Elsevier, Urban & Fischer.
Copyright 2013.)
Vertebral artery
The vertebral artery arises from the superoposterior aspect of the first
part of the subclavian artery. It passes through the foramina in the
transverse processes of all of the cervical vertebrae except the seventh,
curves medially behind the lateral mass of the atlas and enters the
cranium via the foramen magnum (Fig. 29.11). The artery joins its
fellow to form the basilar artery at the lower pontine border. Occasion
ally, it may enter the cervical vertebral column via the fourth, fifth or
seventh cervical vertebra (Fig. 29.12).


NECk
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4
NOITCES
Relations The first part, V1, passes back and upwards between longus supplies the adjacent muscles and gives off one or two spinal branches
colli and scalenus anterior, behind the common carotid artery and the that enter the vertebral canal through the intervertebral foramina to
vertebral vein. It is crossed by the inferior thyroid artery, and by the supply the spinal cord and membranes and vertebral bodies, and
thoracic duct on the left side and the right lymphatic duct on the right thereby supplement the spinal branches of the vertebral artery. The
side. The seventh cervical transverse process, the inferior cervical gan ascending cervical artery anastomoses with the vertebral, ascending
glion and ventral rami of the seventh and eighth cervical spinal nerves pharyngeal, occipital and deep cervical arteries.
lie posterior to the artery. The second part, V2, ascends through the
transverse foramina of the remaining cervical vertebrae, accompanied Inferior laryngeal The inferior laryngeal artery ascends on the
by a large branch from the inferior cervical ganglion and a plexus of trachea with the recurrent laryngeal nerve, enters the larynx at the lower
veins that form the vertebral vein low in the neck. It lies anterior to the border of the inferior constrictor and supplies the laryngeal muscles
ventral rami of the cervical spinal nerves (C2–C6), and ascends almost and mucosa. It anastomoses with its contralateral fellow, and with the
vertically to pass through the transverse process of the axis, where it superior laryngeal branch of the superior thyroid artery.
turns laterally to gain access to the transverse foramen of the atlas (see
Fig. 29.11). The third part, V3, issues medial to rectus capitis lateralis, Pharyngeal branches These supply the lower part of the pharynx.
and curves backwards and medially behind the lateral mass of the atlas, Tracheal branches supply the trachea and anastomose with the bron
with the first cervical ventral spinal ramus lying on its medial side. In chial arteries; oesophageal branches supply the oesophagus and anas


this position, it lies in a groove on the upper surface of the posterior tomose with the oesophageal branches of the thoracic aorta; and
arch of the atlas, and it enters the vertebral canal below the inferior inferior and ascending glandular branches supply the posterior and
border of the posterior atlantooccipital membrane. This part of the inferior regions of the thyroid gland, and anastomose with the contra
artery, covered by semispinalis capitis, lies in the suboccipital triangle. lateral inferior and ipsilateral superior thyroid arteries. The ascending
The first cervical dorsal spinal ramus separates the artery from the pos branch also supplies the parathyroid glands.
terior arch. The fourth part, V4, pierces the dura and arachnoid mater,
and ascends anterior to the hypoglossal roots. It inclines anterior to the Suprascapular artery
medulla oblongata and unites with its contralateral fellow to form the The suprascapular artery descends laterally across scalenus anterior and
midline basilar artery at the lower border of the pons. the phrenic nerve, posterior to the internal jugular vein and sternocleido
mastoid (see Fig. 29.7A). It then crosses anterior to the subclavian artery
Cervical branches of vertebral artery and brachial plexus, posterior to, and parallel with, the clavicle, sub
Spinal branches The spinal branches enter the vertebral canal via clavius and the inferior belly of omohyoid, to reach the superior scapu
the intervertebral foramina and supply the spinal cord and its mem lar border.
branes. They fork into ascending and descending rami, which unite
Superficial cervical artery
with those above and below, to form two lateral anastomotic chains on
the posterior surfaces of the vertebral bodies near the attachment of The superficial cervical artery is given off at a higher level than the
their pedicles. Branches from these chains supply the periosteum and suprascapular artery. It crosses anterior to the phrenic nerve, scalenus
vertebral bodies, and others communicate with similar branches across anterior and the brachial plexus, and is covered by the internal jugular


the midline; from these connections small rami join similar ones above vein, sternocleidomastoid and platysma. It crosses the floor of the pos
and below, to form a median anastomotic chain on the posterior sur terior triangle to reach the anterior margin of levator scapulae, and
faces of the vertebral bodies. ascends deep to the anterior part of the trapezius, which it supplies,
together with the adjoining muscles and the cervical lymph nodes. It
Muscular branches Muscular branches arise from the vertebral anastomoses with the superficial ramus of the descending branch of the
artery as it curves round the lateral mass of the atlas. They supply the occipital artery. About a third of the superficial cervical and dorsal
deep muscles of the suboccipital region and anastomose with the occip scapular arteries arise in common from the thyrocervical trunk, with a
ital, ascending and deep cervical arteries. superficial (superficial cervical artery) and a deep (dorsal scapular
artery) branch (see Figs 26.1, 26.2). The latter passes laterally anterior
Internal thoracic artery to the brachial plexus and then posterior to levator scapulae.
The internal thoracic artery arises inferiorly from the first part of the
Costocervical trunk
subclavian artery, 2 cm above the sternal end of the clavicle, opposite
the root of the thyrocervical trunk (see Fig. 51.2). It is described further On the right, this short vessel arises posteriorly from the second part of
on page 942. the subclavian artery, and, on the left, from its first part. It arches back
above the cervical pleura to the neck of the first rib, where it divides
Thyrocervical trunk into superior intercostal and deep cervical branches.
The thyrocervical trunk is a short, wide artery that arises from the front
Deep cervical artery
of the first part of the subclavian artery near the medial border of sca
lenus anterior, and divides almost at once into the inferior thyroid, The deep cervical artery usually arises from the costocervical trunk (see
suprascapular and superficial cervical arteries. Fig. 26.1). It is analogous in its first segment to a posterior branch of a


posterior intercostal artery, and occasionally is a separate branch of the
Inferior thyroid artery subclavian artery. It passes back above the eighth cervical spinal nerve
The inferior thyroid artery loops upwards anterior to the medial border between the transverse process of the seventh cervical vertebra and the
of scalenus anterior, turns medially just below the sixth cervical trans neck of the first rib (sometimes between the transverse processes of the
verse process, and then descends on longus colli to the lower border of sixth and seventh cervical vertebrae). It then ascends between semi
the thyroid gland (see Figs 29.7A, 29.17). It passes anterior to the ver spinales capitis and cervicis to the level of the second cervical vertebra.
tebral vessels and posterior to the carotid sheath and its contents (and It supplies adjacent muscles and anastomoses with the deep branch of
usually the sympathetic trunk, whose middle cervical ganglion fre the descending branch of the occipital artery and branches of the ver
quently adjoins the vessel). On the left, near its origin, the artery is tebral artery. A spinal branch enters the vertebral canal between the
crossed anteriorly by the thoracic duct as the latter curves inferolaterally seventh cervical and first thoracic vertebrae.
to its termination. Relations between the terminal branches of the artery
Dorsal scapular artery
and recurrent laryngeal nerve are very variable and of considerable
surgical importance. The artery usually passes behind the nerve as it The dorsal scapular artery arises from the third, or less often the second,
nears the gland. However, very close to the gland, the right nerve is part of the subclavian artery. It gives off a small branch (which
equally likely to be anterior, posterior or amongst the branches of the sometimes arises directly from the subclavian artery) to scalenus
artery, and the left nerve is usually posterior. The artery is not accom anterior. It passes laterally through the brachial plexus in front of sca
panied by the inferior thyroid vein. lenus medius and then deep to levator scapulae to the superior scapular
angle.
Muscular branches These supply the infrahyoid muscles, longus
colli, scalenus anterior and the inferior pharyngeal constrictor.
VEINS OF THE NECK


Ascending cervical artery The ascending cervical artery is a small
branch that arises as the inferior thyroid turns medially behind the Veins in the neck show considerable variation. They are superficial or
carotid sheath and ascends on the anterior tubercles of the cervical deep to the deep fascia but are not entirely separate systems. Superficial
transverse processes between scalenus anterior and longus capitis. It veins are tributaries – some with specific names, given below – of the


Vascular supply and lymphatic drainage
459
92
RETPAHC
Digastric, anterior belly Fig. 29.13 The veins of the neck, seen
Anterior jugular vein from the front. The greater part of
sternocleidomastoid has been removed
Submental vein
Facial artery on the left side and the cut lower
edges have been reflected over the
Hypoglossal nerve clavicle. (With permission from
Facial vein
Waschke J, Paulsen F (eds), Sobotta
Atlas of Human Anatomy, 15th ed,
Retromandibular vein Elsevier, Urban & Fischer. Copyright
2013.)
Occipital vein
Facial vein Facial vein
Internal jugular vein
Superior thyroid vein Superior thyroid vein
External jugular vein
Common carotid artery
Internal jugular vein
Sternocleidomastoid
Isthmus thyroid gland
Superficialis cervical vein
External jugular vein
Transverse cervical vein Anterior jugular vein
Omohyoid, inferior belly Omohyoid
Trapezius
Pectoralis major
Cephalic vein
Inferior thyroid vein
Thoraco-acromial vein
Axillary vein
Jugular venous arch
anterior, external and posterior jugular veins (Figs 29.13–29.14). They Anterior jugular vein
drain a much smaller volume of tissue than the deep veins. The latter
The anterior jugular vein arises near the hyoid bone from the confluence
drain all but the subcutaneous structures, mostly into the internal
of the superficial submandibular veins. It descends between the midline
jugular vein and also into the subclavian vein.
and the anterior border of sternocleidomastoid. Turning laterally, low
External jugular vein in the neck, deep to sternocleidomastoid but superficial to the infra
hyoid strap muscles, it either joins the end of the external jugular vein
The external jugular vein mainly drains the scalp and face, although it
or may enter the subclavian vein directly (see Fig. 26.3). In size, it is
also drains some deeper parts. The vein is formed by the union of the
usually inverse to the external jugular vein. It communicates with the
posterior division of the retromandibular vein with the posterior auric


internal jugular vein, and receives the laryngeal veins and sometimes a
ular vein and begins near the mandibular angle just below or in the
small thyroid vein. There are usually two anterior jugular veins, united
parotid gland (see Fig. 26.3). It descends from the angle to the mid
just above the manubrium by a large transverse jugular arch, receiving
clavicle, running obliquely, superficial to sternocleidomastoid, to the
the inferior thyroid tributaries. They have no valves and may be replaced
root of the neck. Here, it crosses the deep fascia and ends in the sub
by a midline trunk.
clavian vein, lateral or anterior to scalenus anterior. There are valves at
its entrance into the subclavian but they do not prevent regurgitation.
Internal jugular vein
Its wall is adherent to the rim of the fascial opening. It is covered by
The internal jugular vein collects blood from the skull, brain, superficial
platysma, superficial fascia and skin, and is separated from sternocleido
parts of the face and much of the neck. It begins at the cranial base in
mastoid by deep cervical fascia. The vein crosses the transverse cutane
the posterior compartment of the jugular foramen, where it is continu
ous nerve and lies parallel with the great auricular nerve, posterior to
ous with the sigmoid sinus. At its origin, it is dilated as the superior
its upper half. In size, the external jugular vein is inversely propor
bulb, which lies below the posterior part of the tympanic floor. The
tional to the other veins in the neck and may be double. Between the
internal jugular vein descends in the carotid sheath, and unites with
entrance into the subclavian vein and a point approximately 4 cm
the subclavian vein, posterior to the sternal end of the clavicle, to form
above the clavicle, the vein is often dilated, producing a socalled
the brachiocephalic vein (see Fig. 29.14). Near its termination, the vein
sinus.
dilates into the inferior bulb, above which is a pair of valves. The jugular


Tributaries In addition to formative tributaries, the external jugular bulb is a dynamic structure; it forms after 2 years of age and its size
stabilizes in adulthood (Friedmann et al 2011).
receives the posterior external jugular and, near its end, transverse cervi
cal, suprascapular and anterior jugular veins. In the parotid gland, it is
often joined by a branch from the internal jugular. The occipital vein Relations From above, rectus capitis lateralis, the transverse process
occasionally joins it. of the atlas, levator scapulae, scalenus medius, scalenus anterior, the
cervical plexus, the phrenic nerve, thyrocervical trunk, vertebral vein
Posterior external jugular vein
and the first part of the subclavian artery all lie posterior to the vein.
The posterior external jugular vein begins in the occipital scalp, and On the left, the internal jugular crosses anterior to the thoracic duct.
drains the skin and the superficial muscles that lie posterosuperior in The internal and common carotid arteries and the vagus nerve are
the neck. It usually joins the middle part of the external jugular vein. medial to the vein; the nerve lies between vein and arteries but posterior


NECk
460
4
NOITCES
Fig. 29.14 The veins of the neck,
Hyoid bone seen from the front and at a
deeper level than shown in Figure
29.13. Both sternocleidomastoids
Retromandibular vein have been removed, and additional
dissection has exposed the thyroid
gland and some of the structures
that pass through the upper
thoracic aperture. (With permission
from Waschke J, Paulsen F (eds),
Occipital vein Hypoglossal nerve
Sobotta Atlas of Human Anatomy,
15th ed, Elsevier, Urban & Fischer.
Copyright 2013.)
Superior thyroid vein
Superior thyroid artery
Thyroid cartilage
Vagus nerve
External jugular vein
Middle thyroid vein
Accessory nerve
Phrenic nerve
Transverse cervical artery Brachial plexus,
supraclavicular part
Transverse Omohyoid
cervical vein
Common
Anterior jugular carotid artery,
vein left recurrent
laryngeal nerve
Subclavian artery
Internal jugular vein
Subclavian vein Subclavian vein
Right brachiocephalic
vein
First rib
Inferior thyroid vein
Vagus nerve
Internal thoracic vein
Left recurrent laryngeal nerve
Superior vena cava
Left brachiocephalic vein Thymic veins
to them. Sometimes, the accessory nerve is found posterior to the vein. it runs obliquely back under platysma. Here it lies superficial to the
Superficially, the internal jugular vein is overlapped above, then covered submandibular gland, digastric and stylohyoid (see Fig. 29.13). Just
below, by sternocleidomastoid, and is crossed by the posterior belly of anteroinferior to the mandibular angle, it is joined by the anterior divi
digastric and the superior belly of omohyoid. The parotid gland, styloid sion of the retromandibular vein, and then descends superficial to the
process, accessory nerve (almost always), and the posterior auricular loop of the lingual artery, the hypoglossal nerve and external and inter
and occipital arteries cross the vein superior to the posterior belly of nal carotid arteries, to enter the internal jugular near the greater cornu


digastric. Between digastric and omohyoid, the sternocleidomastoid of the hyoid bone, i.e. in the upper angle of the carotid triangle. Near
arteries and inferior root of the ansa cervicalis cross it, although the its end, a large branch often descends along the anterior border of
nerve often passes between the vein and the common carotid artery. sternocleidomastoid to the anterior jugular vein. Its uppermost
Below omohyoid, the vein is covered by the infrahyoid muscles and segment, above its junction with the superior labial vein, is often
sternocleidomastoid, and is crossed by the anterior jugular vein. termed the angular vein.
Deep cervical lymph nodes lie along the internal jugular, mainly on its
superficial aspect. At the root of the neck, the right internal jugular vein Tributaries Submental, tonsillar, external palatine (paratonsillar) and
is separated from the common carotid artery, but the left usually over submandibular veins, vena comitans of the hypoglossal nerve (some
laps its artery. At the base of the skull, the internal carotid artery is times), and pharyngeal and superior thyroid veins are all tributaries of
anterior to the vein, separated from it by the ninth to twelfth cranial the portion of the facial vein that lies below the mandible.
nerves.
Lingual vein
Tributaries The inferior petrosal sinus, facial, lingual, pharyngeal, The lingual veins follow two routes. The dorsal lingual veins drain the
superior and middle thyroid veins, and occasionally the occipital vein, dorsum and sides of the tongue, join the lingual veins accompanying
are all tributaries of the internal jugular vein. The internal jugular vein the lingual artery between hyoglossus and genioglossus, and enter the
may communicate with the external jugular vein. The thoracic duct internal jugular near the greater cornu of the hyoid bone. The deep
opens near the union of the left subclavian and internal jugular veins, lingual vein begins near the tip of the tongue and runs back, lying near
and the right lymphatic duct opens at the same site on the right. the mucous membrane on the inferior surface of the tongue. Near the


anterior border of hyoglossus, it joins a sublingual vein, from the sub
Inferior petrosal sinus
lingual salivary gland, to form the vena comitans nervi hypoglossi,
The inferior petrosal sinus leaves the skull through the anterior part of which runs back between mylohyoid and hyoglossus with the hypoglos
the jugular foramen, crosses lateral or medial to the ninth to eleventh sal nerve to join the facial, internal jugular or lingual vein (see Fig. 26.3).
cranial nerves, and joins the superior jugular bulb.
Pharyngeal veins
Facial vein
The pharyngeal veins begin in a pharyngeal plexus external to the
The initial part of the facial vein as it lies on the face is described on pharynx. They receive meningeal veins and a vein from the pterygoid
page 500 (see Fig. 26.3). From the face, it passes over the surface of canal, and usually end in the internal jugular vein, but may sometimes
masseter, crosses the body of the mandible and enters the neck, where end in the facial, lingual or superior thyroid vein.


Vascular supply and lymphatic drainage
461
92
RETPAHC
Superior thyroid vein forwards between the seventh cervical transverse process and the neck
of the first rib to end in the lower part of the vertebral vein.
The superior thyroid vein is formed by deep and superficial tributaries
corresponding to the arterial branches in the upper part of the thyroid Central venous access
gland (see Figs 29.13–29.14). It accompanies the superior thyroid
Central venous cannulation permits monitoring of the central venous
artery, receives the superior laryngeal and cricothyroid veins, and ends
pressure and the administration of drugs directly into the central
in the internal jugular or facial vein.
circulation.
Middle thyroid vein
Internal jugular vein cannulation
The middle thyroid vein drains the lower part of the gland and also
receives veins from the larynx and trachea. It crosses anterior to the
Available with the Gray’s Anatomy e-book
common carotid artery to join the internal jugular vein behind the
superior belly of omohyoid.
Subclavian vein cannulation
Tympanic body
The tympanic body (glomus jugulare) is ovoid, 0.5 mm long and Available with the Gray’s Anatomy e-book
0.25 mm broad, and lies in the adventitia of the upper part of the
superior bulb of the internal jugular vein. It is similar in structure to
the carotid body and is presumed to have a similar function. The pre CERVICAL GROUPS OF LYMPH NODES
dominant cell type has morphological similarities to adrenal chromaf
fin cells, and is derived from the neural crest. Cells obtained from Lymph nodes in the head and neck are distributed in terminal and
glomus jugulare paragangliomas show spontaneous neurite outgrowth outlying groups (Fig. 29.15; see Fig. 26.5). The terminal group is related
in culture and have vasoactive intestinal peptide (VIP)like activity. The to the carotid sheath and the nodes it contains are the deep cervical
tympanic body may be present as two or more parts near the tympanic lymph nodes. All lymph vessels of the head and neck drain into this
branch of the glossopharyngeal nerve or the auricular branch of the group, either directly from tissues or indirectly through nodes in the


vagus as they lie within their canals in the petrous part of the temporal outlying groups. Efferents of the deep cervical nodes form the jugular
bone. Tumours of tympanic bodies often involve the adjacent cranial trunk. The right jugular trunk collects lymph from the right arm, right
nerves and present with pulsatile tinnitus and a husky voice. These half of the thorax and the right head and neck, and may end in the
tumours grow into the hypotympanum of the middle ear; intraluminal jugulosubclavian junction or the right lymphatic duct. The left jugular
growth, both proximally and distally, is well recognized. trunk usually enters the thoracic duct, but it may join the internal
jugular or subclavian vein. For further reading, see Shah and Patel
Subclavian vein
(2012).
The subclavian vein is a continuation of the axillary vein and extends
from the outer border of the first rib to the medial border of scalenus
anterior, where it joins the internal jugular vein to form the brachio
cephalic vein (see Fig. 29.14). The clavicle and subclavius lie anterior Jugulodigastric node
to it; the subclavian artery is posterosuperior, separated by scalenus
anterior and the phrenic nerve; and the first rib and pleura are inferior. Pre-auricular/parotid nodes Mastoid nodes Occipital nodes
The vein usually has a pair of valves 2 cm from its end. Its tributaries
are the external jugular, dorsal scapular and sometimes the anterior
jugular vein. At its junction with the internal jugular, the left subclavian
vein receives the thoracic duct, and the right subclavian vein receives
the right lymphatic duct.
Vertebral vein
Numerous small tributaries from internal vertebral plexuses leave the
vertebral canal above the posterior arch of the atlas and join small
veins from local deep muscles in the suboccipital triangle. Their union
produces a vessel that enters the foramen in the transverse process of
the atlas and forms a plexus around the vertebral artery. It descends
through successive transverse foramina and ends as the vertebral vein.
The vein emerges from the sixth cervical transverse foramen, from


where it descends, at first anterior, then anterolateral, to the vertebral
artery. It may join the deep cervical vein before it opens superoposteri
orly into the brachiocephalic vein (see Fig. 26.4); the opening has a
paired valve. As it descends, it passes behind the internal jugular vein
and anterior to the first part of the subclavian artery. A small accessory
vertebral vein usually descends from the vertebral plexus, traverses the
Superficial
seventh cervical transverse foramen and turns forwards between the
cervical nodes
subclavian artery and the cervical pleura to join the brachiocephalic
vein. Internal
jugular vein
Tributaries The vertebral vein connects with the sigmoid sinus by a
Deep
vessel in the posterior condylar canal, when the latter exists. It also cervical nodes
Submental nodes
receives branches from the occipital vein, prevertebral muscles, and
internal and external vertebral plexuses. It is joined by anterior vertebral
Submandibular nodes
and deep cervical veins (see below), and sometimes, near its end, by
External
the first intercostal vein. Omohyoid jugular vein
Anterior vertebral vein
Jugulo-omohyoid node
The anterior vertebral vein starts in a plexus around the upper cervical
transverse processes, descends near the ascending cervical artery between
attachments of scalenus anterior and longus capitis, and opens into the
end of the vertebral vein.
Fig. 29.15 The superficial lymphatic system in the head and neck. The
Deep cervical vein
nodes are organized into a superficial group around the head, superficial
The deep cervical vein accompanies its artery between semispinales cervical nodes along the external jugular vein, and deep cervical nodes
capitis and cervicis. It is formed in the suboccipital region by the union along the internal jugular vein. (From Drake RL, Vogl AW, Mitchell
of communicating branches of the occipital vein; veins from suboccipi A (eds), Gray’s Anatomy for Students, 2nd ed, Elsevier, Churchill
tal muscles; and veins from plexuses around the cervical spines. It passes Livingstone. Copyright 2010.)


Neck
461.e1
92
RETPAHC
The patient is placed in the supine position with the head turned Subclavian vein cannulation is performed with the patient supine, the
slightly towards the contralateral side. The key anatomical landmarks head turned slightly to the opposite side, and the arms placed by the
are the two inferior heads of sternocleidomastoid, which form two sides side. The bed is tilted down by 10° and a small bedroll may be placed
of a triangle with the clavicle as its base. The internal jugular vein lies between the shoulder blades in order to ensure that the infraclavicular
between the two heads of the muscle, slightly lateral and anterior to the area is more prominent. The skin is cleaned and local anaesthetic
common carotid artery. In infants and children, cannulation of the vein injected into the skin 3 cm lateral to the midpoint of the clavicle. The
carries a high incidence of carotid artery puncture; the vein overlaps the central venous needle is then inserted from the inferior edge of the
artery in the neutral position and head rotation alters the anatomical clavicle towards the suprasternal notch. The needle is directed so that
relation of the two vessels (Hong et al 2010). After the skin has been it passes just below the posterior border of the clavicle; care must be
prepared, local anaesthetic is injected around the apex of the triangle. taken to avoid downward direction of the needle, which may cause a
With one hand palpating the carotid artery, the physician inserts a pneumothorax. Gentle aspiration of the syringe is performed while the
needle at the apex of the triangle and the tip is directed lateral to the needle is being advanced until the subclavian vein is punctured. In
midpoint of the triangle, with a downward angulation of 30°. From a children under the age of 3 years, the supraclavicular approach to the
high internal jugular approach, the needle is inserted at the midpoint subclavian vein is associated with a shorter puncture time and a reduced
of the medial border of sternocleidomastoid and directed towards the incidence of guidewire misplacement compared with the infraclavicular
ipsilateral nipple with a downward angulation of 30–45°. When the approach (Byon et al 2013).


left internal jugular vein is cannulated, additional care must be taken
to avoid the thoracic duct and the cupula of the pleura, which is higher
than on the right side, an arrangement that increases the risk of acci
dental pneumothorax. The left internal jugular vein is often smaller in
diameter than the right (Matthers et al 1992).


NECk
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4
NOITCES
Lymphatic drainage of the neck omohyoid or cricothyroid membrane. Level IV (lower jugular) nodes
lie around the lower third of the internal jugular vein from the inferior
border of level III to the clavicle. The anterior and posterior borders for
Many vessels draining the superficial cervical tissues skirt the borders
levels II, III and IV are the lateral border of sternohyoid and the pos
of sternocleidomastoid to reach the superior or inferior deep cervical
terior border of sternocleidomastoid, respectively. Level V (posterior
nodes. Others pass to the superficial cervical and occipital nodes.
triangle) nodes lie around the lower part of the accessory nerve and the
Lymph from the superior region of the anterior triangle drains to the
transverse cervical vessels.
submandibular and submental nodes. Vessels from the anterior cervi
Knowing which levels of nodes are likely to be involved in the meta
cal skin inferior to the hyoid bone pass to the anterior cervical lymph
static spread of a particular cancer arising in the head and neck means
nodes near the anterior jugular veins. Their efferents go to the deep
that appropriate nodal clearance can be undertaken. The classic radical
cervical nodes of both sides, including the infrahyoid, prelaryngeal
neck dissection first described by Crile in 1906 involved a thorough
and pretracheal groups. An anterior cervical node often occupies the
clearance of levels I–V, including the sacrifice of sternocleidomastoid,
suprasternal space. Lymph from tissues of the head and neck internal
the internal jugular vein and the accessory nerve. Modified radical neck
to the deep fascia drains to the deep cervical nodes directly or through
dissections (socalled functional neck dissections) still remove level I–V
outlying groups that include the retropharyngeal, paratracheal,
nodes but spare either or all of sternocleidomastoid, the internal jugular
lingual, infra hyoid, prelaryngeal and pretracheal groups. The lym
vein and the accessory nerve. Selective neck dissections remove selected
phatic drainage associated with the nasal region, larynx and oral


groups of nodes, e.g. the supraomohyoid neck dissection removes level
cavity is described in the appropriate regions. The deep cervical lym
I–III nodes, the lateral neck dissection removes level II–IV nodes, and
phatic nodes lie alongside the carotid sheath, and form superior and
the posterolateral neck dissection removes level II–V nodes.
inferior groups.
Superior deep cervical nodes The superior deep cervical nodes Cervical lymphovenous portals
adjoin the upper part of the internal jugular vein. Most are deep to
sternocleidomastoid but a few extend beyond it. One subgroup, consist Lymph is returned to the systemic venous circulation via right and left
ing of one large and several small nodes, is in a triangular region lymphovenous portals sited at, or near, the junctions of the internal
bounded by the posterior belly of digastric and the facial and internal jugular and subclavian veins (Fig. 29.16). The arrangement of these
jugular veins, and is known as the jugulodigastric group. It is concerned terminations is variable. Usually, three small lymph trunks converge
especially with drainage of the tongue. Efferents from the upper deep towards their venous junctions on either side of the body and they are
cervical nodes drain either to the lower group or direct to the jugular joined, on the left side only, by the larger thoracic duct.
trunk. On the right side, the three trunks are the right jugular, right sub
clavian and right bronchomediastinal. The right jugular trunk extends
Inferior deep cervical nodes The inferior deep cervical nodes are from the terminal lower deep cervical nodes along the ventrolateral
partly deep to sternocleidomastoid and are particularly related to the aspect of the internal jugular vein, and conveys all the lymph from the
lower part of the internal jugular vein. Some are closely related to the right half of the head and neck. The right subclavian trunk drains from
brachial plexus and subclavian vessels. The juguloomohyoid node lies the terminal apical axillary group. It extends along the axillary and
on, or just above, the intermediate tendon of omohyoid, and is con subclavian veins, and conveys lymph from the right upper limb and


cerned especially with lymphatic drainage from the tongue. Efferents superficial tissues of the right half of the thoracoabdominal wall, down
from this lower group join the jugular lymph trunk. to the umbilicus anteriorly and iliac crest posteriorly (and includes
much of the breast). The right bronchomediastinal trunk ascends
Retropharyngeal nodes Retropharyngeal nodes lie between the over the trachea towards the lymphovenous portal and conveys lymph
pharyngeal and prevertebral fasciae and form a median and two lateral from the thoracic walls, the right cupula of the diaphragm and subja
groups, the latter anterior to the lateral masses of the atlas along the cent liver, the right lung, bronchi and trachea, the greater part of the
lateral borders of longus capitis. The nodes receive afferents from the ‘right heart’ – of clinical parlance, not the geometric right half – and a
nasopharynx, pharyngotympanic tube, and atlantooccipital and proportionately small drainage from the thoracic oesophagus.
atlantoaxial joints, and drain to the upper deep cervical nodes. The three right lymphatic trunks usually open independently (see
Fig. 29.16B). Their orifices are clustered either on the ventral aspect of
Paratracheal nodes The paratracheal nodes flank both trachea and the jugulo/subclavian junction, or in the nearby wall of either of the
oesophagus along the recurrent laryngeal nerves. Efferents pass to the great veins. Sometimes, one or more of the trunks may bifurcate (or
corresponding deep cervical nodes. even trifurcate) preterminally and then terminate via multiple orifices.
Rarely, the three trunks fuse to form a short, single, right lymphatic duct
Infrahyoid, prelaryngeal and pretracheal nodes The infra (about 1 cm long) that inclines across the medial border of scalenus
hyoid, prelaryngeal and pretracheal nodes lie beneath the deep cervical anterior at the root of the neck to reach the ventral aspect of the venous
fascia. They drain afferents from the anterior cervical nodes, and their junction, where its orifice is guarded by a bicuspid semilunar valve. An


efferents join the deep cervical nodes. Infrahyoid nodes are anterior to incomplete right lymphatic duct may be present if the subclavian and
the thyrohyoid membrane, prelaryngeal nodes lie on the cricovocal jugular trunks, or any combination of their terminals, are fused. When
membrane, and pretracheal nodes lie anterior to the trachea near the this occurs, the bronchomediastinal trunk almost invariably opens
inferior thyroid veins. separately.
On the left, the four trunks that converge on the left lymphovenous
Lingual nodes Lingual nodes are small and inconstant, and are situ portal are the left jugular and left subclavian trunks, which have a dis
ated on the external surface of hyoglossus and also between the genio position corresponding to that of their counterparts on the right; the
glossi. They drain to the upper deep cervical nodes. left bronchomediastinal trunk, which has a drainage similar to that of
the right trunk but which drains more of the heart – the ‘left’ and part
Spread of malignant disease in the neck of the ‘right’ hearts of clinical parlance – and more of the oesophagus;
and the thoracic duct, which drains all of the rest of the body (see Fig.
Cancers arising in the head and neck from regions such as the thyroid 29.16A).
gland, larynx, oral cavity and oropharynx, nasopharynx and paranasal
sinuses have predictable patterns of spread through the chains of lymph
INNERVATION
nodes in the neck. When operating on malignant disease in this region,
it is vitally important to understand these patterns of spread so that, for
any individual cancer, the appropriate operation is undertaken. Clinical The skin, joints, viscera and muscles of the neck are innervated by
experience has shown that the lymph nodes in the neck fall into five branches of the glossopharyngeal, vagus and accessory nerves, the cervi
distinct groups (see Fig. 26.5). Level I nodes lie in the submandibular cal spinal nerves and the cervical sympathetic trunk.
triangle bounded by the anterior and posterior bellies of digastric and The first and second cervical dorsal root ganglia lie on the vertebral


the lower border of the mandible above. Level II (upper jugular) nodes arches of the atlas and axis, respectively. The first cervical ganglion may
lie around the upper portion of the internal jugular vein and the upper be absent. Smaller aberrant ganglia sometimes occur on the upper cervi
part of the accessory nerve. They extend from the skull base to the cal dorsal roots between the ganglia and cord. The upper four cervical
bifurcation of the common carotid artery or the hyoid bone. Level III roots are small, and the lower four are large. In general, cervical dorsal
(middle jugular) nodes lie around the middle third of the internal roots have a thickness ratio to the ventral roots of 3 : 1, which is greater
jugular vein from the inferior border of level II to the superior belly of than is seen in other regions. The first dorsal root is an exception, being