Vascular system in the head and neck

1. Vascular system in the Head and
Neck
Diala M. Alghalayini

3. Arteries in the neck
• 2 major arteries: subclavian
artery and common carotid
artery.
• The subclavian artery gives rise
to the vertebral arteries.
• Origin of left and right common
carotid and subclavian arteries is
different.
• Left subclavian and left common
carotid arise from the aortic arch
• While on the right side the
brachiocephalic divides into
common carotid and subclavian
arteries after a short course.

4. Common Carotid Artery

5. CAROTID SHEATH
• Contents of the carotid
sheath:
– Common carotid artery
– Internal jugular vein
– Vagus nerve
• Each common carotid artery ascends through the
neck alongside these structures bound together
by the carotid sheath.

7. Common carotid artery
• Runs upward through the neck under
the cover of the anterior border of the
sternocleidomastoid.
• Divides into internal carotid artery and
external carotid artery.
• Level of bifurcation is usually about the
level of the upper border of the thyroid
cartilage or hyoid bone.
• Internal carotid artery continues
upwards within the carotid sheath.
• External carotid artery leaves the sheath
and becomes external to it.

9. Relations of the common carotid
artery
• Anterolaterally: skin, fascia,
sternocleidomastoid muscle,
sternohyoid, superior belly
of omohyoid.
• Posteriorly: transverse
processes of the lower four
cervical vertebrae,
prevertebral muscles,
sympathetic trunk, vertebral
vessel in the lower part of
the neck.

10. • Medially: larynx, pharynx, trachea, esophegus,
thyroid gland.
• Laterally: internal jugular vein, vagus nerve
posterolaterally.
Relations of the common carotid
artery

12. What is the carotid sinus
•The carotid sinus is a dilatation on the
common carotid artery at its bifurcation,
then continues a little way up the
internal carotid branch.
•It contains barorecptors monitoring
blood pressure
•It is innervated by the carotid branch of
the glossopharyngeal nerve

14. Carotid body
• It is situated behind the
sinus or between the
internal and external carotid
arteries only a few
millimeters in width.
• It contains chemoreceptors
responding to oxygen and
carbon dioxide levels in
blood.
• It is innervated by the
glossopharyngeal nerve

16. External carotid artery
• Begins at the level of the upper border of the
thyroid cartilage.
• Ascends through the upper part of the neck
supplying multiple branches to adjacent
structures.
• It passes deep to the digastric and stylohyoid
muscles then pierces the parotid fascia to enter
the gland at about the level of the angle of the
mandible where it ends by dividing into maxillary
and superficial temporal branches.
• External carotid artery has 8 branches.

17. Relations of the external carotid artery
• Anterolaterally: anterior border of the
sternocleidomastoid muscle, above this level
the artery is superficial, covered by skin and
fascia. Hypoglossal nerve crosses lateral to it.
Posterior belly of digastric, and stylohyoid
muscles (lateral). Internal jugular vein lies
lateral to the artery then posterior to it.

18. Relations of the external carotid artery
• Medially: wall of pharynx, internal carotid
artery, stylopharyngeus muscle and
glossopharyngeal nerve.

19. External carotid artery
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Magnificent.
• S: superior thyroid artery
• A: ascending pharyngeal artery
• L: lingual artery
• F: facial artery
• O: occipital artery
• P: posterior auricular artery
• M: maxillary artery
• S: superficial temporal artery

21. Branches of the external carotid artery
• Superior thyroid artery
– Branch off almost immediately after
the bifurcation. It arises from the
front of the external carotid just
below the level of the hyoid bone.
– Descend and spread out to supply
anterosuperior aspects of thyroid
gland and adjacent muscles
– Has small penetrating branches the
supply the larynx
– It gives off a superior laryngeal
branch which accompanies the
internal laryngeal nerve to the upper
part of the larynx and adjacent part
of the pharynx.

23. Branches of the external carotid artery
• Ascending pharyngeal arteries
– Arise at about the same level as
the superior thyroid arteries,
hidden on the medial aspect of
the external carotid artery.
– Ascend on the side of the pharynx
and supply it.
– At the base of the skull it gives off
a number of small meningeal
branches which enter the cranial
cavity through the foramen
lacerum and the jugular foramen.
– Contributes to the blood supply of
the palatine tonsils

25. Branches of the external carotid artery
• Lingual artery
– Lingual and facial artery may arise separately from a short
common stem.
– It leaves the anterior surface of the external carotid opposite
the hyoid bone. It runs forwards, making a characteristic
upward loop, and then passes deep to the hyoglossus muscle
to enter the floor of the mouth.
– Lingual artery passes deep to the mandible and cross the floor
of the mouth to ascend into the tongue.
– It supplies the tongue and floor of the mouth.

27. Branches of the external carotid artery
• facial artery
– arises from the front of the external carotid artery a short
distance above the lingual artery. It runs upwards in a deep groove
on the posterior surface of the submandibular gland and deep to
the ramus of the mandible, curves over the superior aspect of the
gland and then runs downwards and forwards between the lateral
surface of the gland and the medial surface of the mandible. It
hooks around the inferior border of the mandible at the anterior
edge of masseter to enter the face.
– In the neck it gives off an ascending palatine branch which
ascends alongside the pharynx to supply the soft palate, a tonsillar
branch to the palatine tonsil and a submental branch which runs
forwards on the superficial surface of the mylohyoid muscle to
supply nearby muscles and skin.

28. Branches of the Facial artery
• cervical
– Ascending palatine artery
– Tonsillar branch
– Submental artery
– Glandular branches
• facial
– Inferior labial artery
– Superior labial artery
– Lateral nasal branch to nasalis muscle
– Angular artery - the terminal branch

31. Branches of the external carotid artery
• occipital artery
– leaves the back of the external
carotid above the level of the
hyoid bone. Runs medial to the
digastric muscle and then in the
occipital groove on the mastoid
part of the temporal bone. On
leaving the occipital groove it
turns superficially to supply the
posterior part of the scalp.

33. • posterior auricular artery
– arises from the posterior part of the external carotid above
the digastric muscle. It ascends, between the parotid gland
and styloid process
– supplies the auricle and scalp behind the ear.
– at the stylomastoid foramen it gives off its stylomastoid
branch which runs through the foramen to supply the
tympanic cavity.
Branches of the external carotid artery

35. • Superficial temporal artery
– begins in the parotid gland immediately behind the neck of the
mandible, runs upwards across the posterior root of the zygomatic
process of the temporal bone where it can be palpated in front of
the auricle and then divides into anterior and posterior branches
– crossed by the upper branches of the facial nerve within the
parotid gland and accompanied in the scalp by the corresponding
veins and the auriculotemporal nerve.
– It supplies the scalp.
Branches of the external carotid artery

36. Branches of the external carotid artery
• Superficial temporal artery
• Before dividing into its terminal branches the artery gives off
several branches.
– the transverse facial artery : arises in the parotid gland and runs
forwards across the masseter muscle supplying the gland and its duct
and the masseter muscle
– branches to the external ear
– zygomatic artery which runs along the upper border of the zygomatic
arch towards the lateral angle of the eye supplying adjacent muscles
– middle temporal artery which arises above the zygomatic arch,
pierces the temporal fascia and supplies, together with the deep
temporal branch of the maxillary artery, the temporalis muscle.
– The terminal anterior and posterior branches supply the frontal and
parietal regions of the scalp respectively

39. Maxillary Artery
• One of the terminal branches of the external
carotid artery, it begins in the parotid gland
posterior to the neck of the mandible.
• enters the infratemporal fossa by curving
forwards deep to the mandibular neck. then
crosses the lower head of the lateral pterygoid,
usually lying superficial but occasionally deep to
that belly, to enter the pterygopalatine fossa
through the pterygomaxillary fissure.

40. Branches of the first part
• It is posterior to lateral pterygoid muscle
(five branches)
• Five branches, each of which enters a bony
foramen:
– The deep auricular artery supplies the
lining of the external acoustic meatus
– the anterior tympanic artery passes
through the petrotympanic fissure to
supply part of the lining of the
tympanic cavity.
– The middle meningeal artery provides
the principal source of blood to the
meninges. It ascends deep to lateral
pterygoid, passes between the two
roots of the auriculotemporal nerve,
enters the cranial cavity through the
foramen spinosum.

41. – The accessory meningeal artery ascends in
front of the middle meningeal artery to
enter the skull through the foramen ovale.
It gives branches to neighbouring muscles
before entering the foramen.
– The inferior alveolar artery runs
downwards posterior, and in close
relationship, to the nerve of the same
name. Before entering the mandibular
foramen it gives off its mylohyoid branch
which pierces the sphenomandibular
ligament and passes to the superficial
aspect of the mylohyoid muscle in
company with the corresponding nerve.
The inferior alveolar artery runs forwards
in the mandibular canal to supply the bone
of the lower jaw, the inferior dentition and,
through its mental branch, the lower lip
Branches of the first part

42. Branches of the second part
• within lateral pterygoid muscle (five
branches)
o The second part of the artery
gives two deep temporal
arteries branches to the
temporalis muscle, anterior
temporal, posterior temporaL
o pterygoid branches to the
pterygoid muscles
o the masseteric branch which
passes to the masseter muscle
o the buccal branch which
accompanies the buccal nerve to
supply the structures of the
cheek.
o A small lingual branch
accompanies the lingual nerve

43. Branches of the third part
• that part of the vessel within the
pterygopalatine fossa) gives off
– posterior superior alveolar artery
– infraorbital artery (enters infrerior
orbital fissure) gives anterior
superior alveolar artery, and middle
superior alveolar artery.
– artery of the pterygoid canal
– pharyngeal artery
– greater (descending) palatine
artery (enters greater palatine
foramen)
– sphenopalatine artery terminal
branch (enters sphenopalatine
foramen)

44. Maxillary artery Branches
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45. Maxillary Artery Branches
• D: deep auricular artery
• A: anterior tympanic artery
• M: middle meningeal artery
• I: inferior alveolar artery
• A: accessory meningeal artery
• M: masseteric artery
• P: pterygoid artery
• D: deep temporal artery
• B: buccinator artery
• S: sphenopalatine artery
• D: descending palatine artery
• I: infraorbital artery
• P: posterior superior alveolar artery
• M: middle superior alveolar artery
• P: pharyngeal artery
• A: anterior superior alveolar artery
• A: artery of the pterygoid canal

48. Internal carotid artery
• The internal carotid artery continues upwards within
the carotid sheath from its origin at the bifurcation of
the common carotid.
• It lies at first superficial to the external carotid artery
but as it ascends it comes to occupy a position behind
and deep to it.
• At the base of the skull it enters the carotid canal and
gains access to the cranial cavity.
• The internal carotid artery has no branches within the
neck. Its branches are in the cranial cavity.
• The artery carries with it a network of nerves (the
internal carotid plexus) from the superior cervical
ganglion.

49. Internal carotid artery

50. Internal carotid artery
• In the cranial cavity the artery
passes upward and forward in
the cavernous sinus without
communicating with it.
• Passes medial to the anterior
clinoid process. It inclines
backward lateral to the optic
chiasma.
• Terminates by dividing into
anterior and middle cerebral
artery.

51. Relations of the Internal carotid artery
• Anterolaterally:
– Below the digastric: skin, fascia, anterior border of
the sternocleidomastoid, and hypoglossal nerve.
– Above the digastric: stylohyoid muscle,
stylopharyngeus muscle, glossopharygeal nerve,
pharyngeal branch of vagus, parotid gland,
external carotid artery.

52. • Posteriorly: sympathetic trunk, longus capitis
muscle, transverse processes of upper 3
cervical vertebrae.
• Medially: pharyngeal wall, superior laryngeal
nerve.
• Laterally: internal jugular vein, vagus nerve.
Relations of the Internal carotid artery

53. Branches of the internal carotid artery
• There are no branches in the neck, branches
are given off in the skull:
• Ophthalmic artery: arises as the internal
carotid artery emerges from the cavernous
sinus. Passes through the optic canal and gives
off the central artery into the eyeball. The
central artery is the only artery to supply the
retina.

54. • Posterior communicating artery: runs backwards
and joins posterior cerebral artery.
• Anterior cerebral artery: terminal branch of the
internal carotid, passes forward between the
cerebral hemispheres, winds around the corpus
callosum of the brain. Supplies the medial and
superolateral surfaces of the cerebral
hemispheres. Joins the artery of the opposite
side by the anterior communicating atery.
Branches of the internal carotid artery

55. • Middle cerebral artery: largest terminal branch of
the internal carotid artery, runs laterally in the
lateral cerebral sulcus of the brain. Supplies the
entire lateral surface of the cerebral hemisphere
except a narrow strip along the superolateral
margin (anterior cerebral artery), the occipital
pole and inferolateral surface of the hemisphere
(posterior cerebral artery)
• Middle cerebral artery supplies all motor area of
the cerebral cortex except leg area.
Branches of the internal carotid artery

57. Circle of Willis
• It lies in the subarachnoid space at the
base of the brain.
• The circulus is formed by the
anastomosis between the branches of
the 2 internal carotid arteries and the
2 vertebral arteries.
• The communicating vessels are small
and are usually inadequate to
maintain sufficient circulation to the
brain if one or other of the internal
carotid arteries is suddenly blocked.
• They are capable of expanding if the
blockage occurs more slowly so that
an adequate cerebral blood supply
may be maintained.
• Cortical and central branches arise
from the circle to supply the brain.

59. Vertebral artery
• The vertebral artery is a branch of the subclavian artery. It ascends
through the neck, in the foramina in the transverse processes of
the upper six cervical vertebrae
• around the lateral mass of the atlas and enters the cranial cavity
through the foramen magnum. Here it pierces the dura and
arachnoid mater and runs in the subarachnoid space upwards and
medially in front of the rootlets of the hypoglossal nerve to join
the artery of the opposite side at the lower border of the pons.
The artery so formed is the basilar. At upper border of the pons it
divides into right and left posterior cerebral arteries
• Within the cranial cavity the vertebral artery gives rise to spinal
branches which pass downwards to the spinal canal, a posterior
inferior cerebellar branch to the cerebellum and medullary
branches to the medulla oblongata. Arising from either side of the
basilar artery are pontine branches, a labyrinthine branch to the
internal ear, anterior inferior and superior cerebellar branches and
the posterior cerebral artery.

61. Veins of the head and neck
• Veins of the brain, venous sinuses, diploic
veins, emissary veins.
• Veins of the scalp, face, and neck

62. Veins of the brain
• Cerebral veins, cerebellar veins, veins of the
brainstem, all of which drain into neighboring
venous sinuses.

63. Venous sinuses of dura mater
• Apart from the inferior sagittal and straight sinuses, these
venous channels lie between the endosteal and meningeal
layers of the dura mater. Unlike other veins in the body
they run alone, not parallel to arteries.
• Like other veins they are lined by endothelium but contain
no valves allowing for bidirectional blood flow in
intracranial veins and have walls devoid of muscular tissue.
They receive blood from the brain (through the cerebral
veins), from the bones of the braincase (via the diploic
veins) and from the meninges.
• Together the dural venous sinuses form the major
drainage pathways from the brain, predominantly to the
internal jugular veins.

64. Superior sagittal sinus
• The superior sagittal sinus lies
between the two leaves of the
falx cerebri at their attachment
to the cranial vault.
• Extending laterally from the
sinus are a variable number of
venous lakes. These lie alongside
the sinus between the two layers
of the dura.
• Opening into the superior
sagittal sinus are the superior
cerebral veins draining blood
from the superior, lateral and
medial surfaces of the cerebral
hemispheres.

65. Inferior sagittal sinus
• This is situated
between the two
leaves of the falx
cerebri at its
inferior, free
margin. Begins just
above the crista
galli, enlarges as it
runs posteriorly. It
receives blood from
the falx.

66. Straight sinus
• runs posteriorly in the
junction of the falx
cerebri and the
tentorium cerebelli. It
drains the inferior sagittal
sinus and receives the
great cerebral vein
(containing blood from
the deep parts of the
cerebral hemispheres).

67. Transverse sinus
• drains the superior sagittal
sinus and is usually larger. at
the junction of petrous and
mastoid parts of the
temporal bone the
transverse sinus curves
downwards to become the
sigmoid sinus.
• It receives inferior cerebral,
cerebellar, and diploic veins
and, near its continuation
with the sigmoid sinus, the
superior petrosal sinus.

68. Sigmoid sinus
• its continuation with the transverse sinus to
the jugular foramen, producing a deep groove
on the endocranial surface of the mastoid part
of the temporal bone.
• In the posterior part of the jugular foramen it
expands to form the jugular bulb which is
continuous below with the internal jugular
vein.

69. Cavernous sinus
• The right and left cavernous sinuses lie each side of the body of the
sphenoid.
• The walls of the sinus are traversed by the internal carotid artery,
the nerves to the extraocular muscles and the first two divisions of
the trigeminal nerve.
• receives blood from the middle cerebral vein (draining the lateral
surface of the hemisphere), the sphenoparietal sinus (from the dura
mater over the temporal region), and the superior and inferior
ophthalmic veins (from the orbit).
• Communications:
– Before entering the sinus, the inferior ophthalmic vein communicates
with the pterygoid plexus of veins through the inferior orbital fissure.
The cavernous sinus also communicates directly with the pterygoid
plexus by emissary veins transmitted through the foramen ovale
 The sinus drains into the superior and inferior petrosal sinuses.

70. Cavernous sinus
• Several important structures are related to the
cavernous sinus:
– The internal carotid artery curves upwards
from the opening of the carotid canal to enter
the posterior part of the sinus.
– The abducent nerve passes the medial wall of
the cavernous sinus between the internal
carotid artery and the endothelium lining the
cavernous sinus.
– The ophthalmic and maxillary divisions of the
trigeminal nerve form the lateral wall of the
cavernous sinus and the lining endothelium.
The ophthalmic nerve is the more superior of
the two and divides into its three branches
(lacrimal, frontal, and nasociliary) while still in
the wall of the sinus.
– The trochlear nerve enters the roof of the
cavernous sinus and then runs forwards in its
lateral wall, above the ophthalmic nerve
– The oculomotor nerve enters the roof of the
sinus in front of the trochlear nerve. It also runs
forwards in the lateral wall of the sinus.

71. Superior petrosal sinus
• The superior petrosal sinus drains out of the
posterior part of the cavernous sinus. It ends
by entering the junction of the transverse and
sigmoid sinuses.

72. Inferior petrosal sinus
• leaves the posterior part of the cavernous
sinus and passes downwards, between the
two layers of the dura, along the
petrooccipital fissure to enter the anterior
part of the jugular foramenit joins the internal
jugular vein a short distance below the cranial
base.

73. Diploic veins
• Veins that occupy
channels within the bones
of the vault of the skull.

74. Emissary veins
• Valveless veins that
pass through the skull
bones. They connect
veins of the scalp to
the venous sinuses

75. Facial vein
• The forehead is drained by supratrochlear and
supraorbital veins which pass downwards
towards the inner angle of the eye where they
fuse to form the facial vein.
• It is connected to the cavernous sinus through
the ophthalmic vein.
• This vein runs downwards and backwards in
company with, and just posterior to the facial
artery but following a less tortuous course. It
receives tributaries corresponding to the
branches of the facial artery.

76. Facial vein
• On the anterior part of the masseter muscle
the facial vein crosses the lower border of the
mandible, passes through the deep fascia and
enters the neck. Here it is joined by the
anterior division of the retromandibular vein
and then drains into the internal jugular vein.
• A communication channel, the deep facial
vein, connects the facial vein with the
pterygoid within the infratemporal fossa.

77. The superficial temporal vein
• It is formed on the side of the scalp. Just
above the zygomatic arch it receives the
middle temporal vein from the temporalis
muscle and a little below this level the
transverse facial vein from the side of the face.
• It then enters the parotid gland where it
unites with the maxillary vein to form the
retromandibular vein.

79. Maxillary vein
• It is formed in the infratemporal fossa from
the pterygoid venous plexus. It joins the
superficial temporal vein to form the
retromandibular vein.

80. Retromandibular vein
• It descends within the parotid gland, deep to the
facial nerve but superficial to the external carotid
artery. While still within the gland or after
emerging from it the vein splits into anterior and
posterior divisions. The anterior division passes
forwards to join the facial vein. The posterior
division continues more directly downwards and
is joined, either within or just outside the gland,
by the posterior auricular vein to form the
external jugular vein.

82. External jugular vein
• The external jugular vein is formed by the union of the posterior division
of the retromandibular vein and the posterior auricular vein.
• It runs downwards superficial to the sternocleidomastoid muscle, pierces
the deep cervical fascia above the middle of the clavicle, and ends in the
subclavian vein. It receives a few small tributaries from adjacent
structures.
– Anterior jugular vein begins beneath the chin, on each side of the
midline, and passes downwards to the suprasternal region where it
pierces the deep fascia and empties into the external jugular vein.
– Occipital vein This large vein drains the occipital region of the scalp. It
passes deep between the extensor muscles of the cervical vertebral
column and usually opens into the vertebral vein.
– Vertebral vein is formed in the region below the occipital bone by the
union of numerous tributaries from the vertebral plexuses and from
the deep musculature of the suboccipital region. It passes downwards
in the foramina in the transverse processes of the upper six cervical
vertebrae and ends by joining the brachiocephalic vein of the same
side.

84. Internal jugular Vein
• Large vein that receives blood from the brain, face and
neck.
• Starts as a continuation of the sigmoid sinus and leaces the
skull through the jugular foramen to lie at first behind the
internal carotid artery.
• Immediately below the cranial base it receives the inferior
petrosal sinus.
• The vein passes downwards in the loose part of the carotid
sheath lateral to the internal carotid artery and, at a lower
level, to the common carotid artery. Between the vein and
the arteries is the vagus nerve.
• In the root of the neck the internal jugular vein joins the
subclavian vein to form the brachiocephalic vein.

85. Internal jugular vein
• The internal jugular is crossed superficially by
the posterior belly of digastric, omohyoid, and
sternocleidomastoid muscles, the posterior
auricular and occipital arteries, and the
accessory nerve and ansa cervicalis.
• In the lower part of its course it is covered by
the infrahyoid muscles.

86. Internal jugular vein
• Tributaries
– inferior petrosal sinus
– pharyngeal veins
– facial vein
– lingual vein
– superior thyroid vein
– middle thyroid vein

88. Pterygoid plexus of veins
• This venous plexus lies around within the lateral
pterygoid muscle. Its tributaries correspond to the
branches of the three parts of the maxillary artery
although the area drained is smaller than that supplied
by the artery. Blood from the periphery area drains via
other routes such as the facial vein.
• It communicates with
– the facial vein through the deep facial vein.
– cavernous sinus by means of one or more emissary veins
passing through the foramen ovale.
– inferior ophthalmic vein through the inferior orbital fissure.
• It drains through the short but wide maxillary vein.

89. • Its importance in dentistry lies in the
fact that it may be punctured by a
needle delivering local anaesthetic
solution to the posterior superior
alveolar nerves, an event which may
be followed by copious bleeding into
the surrounding tissues. Blood may
pass forwards through the inferior
orbital fissure into the orbit with
production of a ‘black eye’.
• Through its communications the
plexus forms a potential route
whereby infection may spread from its
area of drainage (including the jaws
and, through the deep facial vein, the
face) to the cavernous sinus.
Pterygoid plexus of veins

91. Management
• Reassurance of the patient
• Cold compresses.