The document discusses the circulatory system of the head and neck, including key arteries and structures: - The common carotid artery divides into the external and internal carotid arteries, with the external supplying blood to the face and neck and the internal supplying the brain. - Important structures along the carotid arteries include the carotid body, which detects changes in blood gases, and the carotid sinus, a baroreceptor site. - Branches of the external carotid artery include the superior thyroid artery and branches that supply the face and pharynx. The internal carotid artery branches further within the skull to supply the brain.

1. Circulatory system of
head and neck
DR.C.P.ARYA
B.SC.;B.D.S ;M.D.S.;P.M.S.

2. contents INTRODUCTION
 BLOOD VESSELS
 HISTOLOGY OF BLOOD VESSELS
 ARTERIES
 ARTERIAL WALL
 ARTERIES IN HEAD & NECK
 CAROTID SHEATH
 CAROTID BODY
 CAROTID SINUS
 COMMON CAROTID ARTERY
 EXTERNAL CAROTID ARTERY
 BRANCHES OF EXTERNAL CAROTID ARTERY
 INTERNAL CAROTID ARTERY
 BRANCHES OF INTERNAL CAROTID ARTERY
 SUBCLAVIAN ARTERY
 CAPILLARIES
 VEINS
 VENOUS SINUSES
 VEINS OF HEAD & NECK
 REFERENCES

3. The cardiovascular system is sometimes called the blood-
vascular, or simply the circulatory, system. It consists of
the heart, which is a muscular pumping device, and a closed
system of vessels called arteries, veins, and capillaries. As
the name implies, blood contained in the circulatory system
is pumped by the heart around a closed circle or circuit of
vessels as it passes again and again through the various
"circulations" of the body.
INTRODUCTION

4. As in the adult, survival of the developing embryo depends
on the circulation of blood to maintain homeostasis and a
favorable cellular environment. In response to this need, the
cardiovascular system makes its appearance early in
development and reaches a functional state long before any
other major organ system. Incredible as it seems, the
primitive heart begins to beat regularly early in the fourth
week following fertilization.
INTRODUCTION

5. • The cardiovascular system of the head and neck includes
the vital arteries that provide oxygenated blood to the
brain and organs of the head, including the mouth and
eyes. It also includes the veins that return
deoxygenated blood from these organs to the heart.
Among these blood vessels are several unique and
important structures that have evolved to help maintain
the continuous flow of blood to the brain. The human
brain is so powerful and metabolically active that it uses
about 20% of all of the oxygen and glucose taken in by
the body each day.
INTRODUCTION

6. Vascular system

7. Blood vessels
 Blood vessels are the channels or
conduits through which blood is
distributed to body tissues. The
vessels make up two closed
systems of tubes that begin and
end at the heart. One system, the
pulmonary vessels, transports
blood from the right ventricle to the
lungs and back to the left atrium.
The other system, the systemic
vessels, carries blood from the left
ventricle to the tissues in all parts
of the body and then returns the
blood to the right atrium. Based on
their structure and function, blood
vessels are classified as either
arteries, capillaries, or veins.

8.  All blood vessels
except capillaries
have 3 basic tunic or
coats- concentrically
arranged-
a. TUNICA INTIMA
b. TUNICA MEDIA
c. TUNICA ADVENTIA
Histology of blood
vessels

9.  The walls of arteries and
veins are composed of
endothelial cells, smooth
muscle cells and
extracellular matrix
(including collagen and
elastin). These are
arranged into three
concentric layers: intima,
media and adventitia.
 The intima is the inner
layer abutting the vessel
lumen. The adventitia is
the outer layer abutting
the perivascular soft
tissue. The media is
sandwiched between the
intima and adventitia.
Histology of blood vessels

10.  The intima is the thinnest
layer. It is composed of a
single layer of endothelial
cells and a small amount of
subendothelial connective
tissue. The intima is
separated from the media by
a dense elastic membrane
called the internal elastic
lamina.
 The adventitia is composed of
connective tissue, nutrient
vessels (vasa vasorum) and
autonomic nerves (nervi
vasorum).
Histology of blood vessels

11. The media is the thickest layer and
provides structural support,
vasoreactivity and elasticity. It is
composed of smooth muscle cells,
elastic fibres and connective tissue,
which vary in amount depending on the
type of vessel. Smooth muscle cells
contract (vasoconstriction) or relax
(vasodilatation), which is controlled by
autonomic nerves (nervi vasorum) and
local metabolic factors. Elastic fibres
allow the vessel to expand with systole
and contract with diastole, thereby
propelling blood forward. The media is
separated from the adventitia by a
dense elastic membrane called the
external elastic lamina.
Histology of blood vessels

12.  The intima and inner
part of the media are
nourished by
diffusion of oxygen
and nutrients from
blood in the lumen,
and the adventitia
and outer part of the
media are nourished
by vasa vasorum.
Histology of blood
vessels

13. Arteries

14.  Arteries carry blood away from the heart. Pulmonary arteries
transport blood that has a low oxygen content from the right
ventricle to the lungs. Systemic arteries transport oxygenated
blood from the left ventricle to the body tissues. Blood is
pumped from the ventricles into large elastic arteries that
branch repeatedly into smaller and smaller arteries until the
branching results in microscopic arteries called arterioles. The
arterioles play a key role in regulating blood flow into the tissue
capillaries. About 10 percent of the total blood volume is in the
systemic arterial system at any given time.
Arteries

15.  The wall of an artery consists of three layers. The innermost layer,
the tunica intima (also called tunica interna), is simple squamous
epithelium surrounded by a connective tissue basement membrane
with elastic fibers. The middle layer, the tunica media, is primarily
smooth muscle and is usually the thickest layer. It not only provides
support for the vessel but also changes vessel diameter to regulate
blood flow and blood pressure. The outermost layer, which attaches
the vessel to the surrounding tissue, is the tunica externa or tunica
adventitia. This layer is connective tissue with varying amounts of
elastic and collagenous fibers. The connective tissue in this layer is
quite dense where it is adjacent to the tunic media, but it changes
to loose connective tissue near the periphery of the vessel.
ArteriAL WALL

17. The walls of arteries are thicker than that of veins to
withstand pulsatile flow and higher blood pressures. As
arteries become smaller, wall thickness gradually decreases
but the ratio of wall thickness to lumen diameter increases
(i.e. relative lumen size decreases).
Arteries are divided into three types according to size and
function. The constituents of the media of these vessels
differ in their relative amounts accordingly.
Large elastic arteries (aorta, large aortic branches [eg.
innominate, subclavian, common carotids, iliacs] and
pulmonary arteries) – the media is abundant in elastic fibres
that allow it to expand with systole and recoil during
diastole, thereby propelling blood forward.
ArteriAL WALL

18.  Medium-sized muscular arteries (other aortic branches, eg.
coronary and renal arteries) – the media is abundant in smooth
muscle cells that vasoconstrict or vasodilate, thereby
controlling lumen diameter and regional blood flow.
 Small arteries and arterioles (in the substance of organs and
tissues) - the media is abundant in smooth muscle cells that
vasoconstrict or vasodilate. In vessels of this size, smooth
muscle contraction causes dramatic changes in lumen diameter,
thereby controlling systemic blood pressure as well as regional
blood flow.
ArteriAL WALL

19.  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.
ArteriES IN HEAD& NECK
The common carotid artery arises directly
from the aorta on the left, and as a branch
of the brachiocephalic trunk on the right.

20. ArteriES IN HEAD& NECK

21. ArteriES IN HEAD& NECK

22.  The carotid sheath is an
anatomical term for the
fibrous connective tissue
that surrounds the vascular
compartment of the neck.
 It is part of the deep
cervical fascia of the neck,
below the superficial
cervical fascia meaning the
subcutaneous adipose
tissue immediately beneath
the skin.
CArOTID SHEATH

23.  The carotid sheath is located at the
lateral boundary of the
retropharyngeal space at the level
of the oropharynx on each side of
the neck and deep to the
sternocleidomastoid muscle,
extending from the base of the skull
to the first rib and sternum.
 The four major structures contained
in the carotid sheath are:
1. the common carotid artery as well
as the internal carotid artery
(medial)
2. internal jugular vein (lateral)
3. the vagus nerve (CN X) (posterior)
4. the deep cervical lymph nodes
CArOTID SHEATH

24.  The carotid body is made up of two types of cells,
called glomus cells: glomus type I cells are
peripheral chemoreceptors, and glomus type II
cells are sustentacular supportive cells.
 Glomus type I cells are derived from neural crest,
which, in turn are derived from neuroectoderm.
They release a variety of neurotransmitters,
including acetylcholine, ATP, and dopamine that
trigger EPSPs in synapsed neurons leading to the
respiratory center.
 Glomus type II cells resemble glial cells, express
the glial marker S100 and act as supporting cells.
 The carotid body contains the most vascularized
tissue in the human body. The thyroid gland is
very vascular, but not quite as much as the
carotid body.
CArOTID body

25.  The carotid body (carotid
glomus or glomus caroticum) is
a small cluster of
chemoreceptors and supporting
cells located near the fork
(bifurcation) of the carotid
artery (which runs along both
sides of the throat).
 The carotid body detects
changes in the composition of
arterial blood flowing through
it, mainly the partial pressure of
arterial oxygen, but also of
carbon dioxide. Furthermore, it
is also sensitive to changes in
pH and temperature.
CArOTID body
Section of part of human glomus
caroticum. Highly magnified.
Numerous blood vessels are seen
in section among the gland cells.

26. FUNCTION:
The carotid body
functions as a sensor: it
responds to a stimulus,
primarily O2 partial
pressure, which is
detected by the type I
(glomus) cells, and
triggers an action
potential through the
afferent fibers of the
glossopharyngeal
nerve, which relays the
information to the
central nervous system.
CArOTID body

27.  In human anatomy, the
carotid sinus is a dilated area
at the base of the internal
carotid artery just superior to
the bifurcation of the internal
carotid and external carotid
at the level of the superior
border of thyroid cartilage.
The carotid sinus extends
from the bifurcation to the
"true" internal carotid artery.
The carotid sinus is sensitive
to pressure changes in the
arterial blood at this level. It
is the major baroreception
site in humans and most
mammals.
CArOTID sinus

28.  Massage of the carotid sinus,
carotid sinus massage is used
to diagnose carotid sinus
syncope and is sometimes
useful for differentiating
supraventricular tachycardia
(SVT) from ventricular
tachycardia. Like the valsalva
maneuver, it is a therapy for
SVT. It is less effective than
pharmaceutical management
of SVT with verapamil or
adenosine though is still the
preferred first line of
treatment in a
hemodynamically stable
patient.
Carotid sinus MASSAGE

29.  In anatomy, the left and right
common carotid arteries (carotids)
are arteries that supply the head and
neck with oxygenated blood; they
divide in the neck to form the
external and internal carotid
arteries.
 Runs upward through the neck under
the cover of the anterior border of
the sternocleidomastoid.
 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.
COMMON CArOTID ARTERY

30.  Anteroposteriorly: Skin fascia,
Sternocleidomastoid muscle,
Sternohyoid, Superior belly of
Omohyoid.
 Posteriorly: Transverse
process of the lower 4 cervical
vertebrae, Prevertebral
muscles, Sympathetic trunk,
Vertebral vessel in the lower
part of the neck.
 Medially: Larynx, Pharynx,
Trachea, Oesophagus, Thyroid
gland.
 Laterally: Internal Jugular
vein, Vagus nerve
posterolaterally.
Relations of COMMON CArOTID ARTERY

31. External CArOTID ARTERY
 The external
carotid artery is
a major artery of
the head and
neck. It arises
from the
common carotid
artery when it
splits into the
external and
internal carotid
artery. It
supplies blood to
the face and
neck.

32. Structure
 The external carotid artery begins at the upper border of thyroid
cartilage, and curves, passing forward and upward, and then
inclining backward to the space behind the neck of the mandible,
where it divides into the superficial temporal and maxillary artery
within the parotid gland.
 It rapidly diminishes in size as it travels up the neck, owing to the
number and large size of its branches.
 At its origin, this artery is closer to the skin and more medial than
the internal carotid, and is situated within the carotid triangle.
Development
 In children, the external carotid artery is somewhat smaller than
the internal carotid; but in the adult, the two vessels are of nearly
equal size.
External CArOTID ARTERY

33. Relations
 The external carotid artery is covered by the skin, superficial fascia,
Platysma, deep fascia, and anterior margin of the Sternocleidomastoideus; it
is crossed by the hypoglossal nerve, by the lingual, ranine, common facial,
and superior thyroid veins; and by the Digastricus and Stylohyoideus; higher
up it passes deeply into the substance of the parotid gland, where it lies
deep to the facial nerve and the junction of the temporal and internal
maxillary veins.
 Medial to it are the hyoid bone, the wall of the pharynx, the superior
laryngeal nerve, and a portion of the parotid gland.
 Lateral to it, in the lower part of its course, is the internal carotid artery.
 Posterior to it, near its origin, is the superior laryngeal nerve; and higher up,
it is separated from the internal carotid by the Styloglossus and
Stylopharyngeus, the glossopharyngeal nerve, the pharyngeal branch of the
vagus, and part of the parotid gland.
External CArOTID ARTERY

34. Function
 As the artery travels upwards, it supplies:
 In the carotid triangle:
 Superior thyroid artery, arising from its anterior aspect
 Ascending pharyngeal artery - arising from medial, or deep, aspect
 Lingual artery - arising from its anterior aspect
 Facial artery - arise from its anterior aspect
 Occipital artery - arising from its posterior aspect
 Posterior auricular artery - arising from posterior aspect
 The external carotid artery terminates as two branches:
 Maxillary artery
 Superficial temporal artery
External CArOTID ARTERY

35. Branching of External
CArOTID ARTERY

36. She Always Likes Friends Over Papa,
Sister, and Mama
 S: superior thyroid artery
 A: ascending pharyngeal artery
 L: lingual artery
 F: facial artery
 O: occipital artery
 P: posterior auricular artery
 S: superficial temporal artery
 M: maxillary artery
Branches of the external carotid artery (mnemonic)

37.  The superior thyroid artery arises
from the external carotid artery just
below the level of the greater cornu of
the hyoid bone and ends in the thyroid
gland.
Structure
 From its origin under the anterior
border of the sternocleidomastoid the
superior thyroid artery runs upward
and forward for a short distance in the
carotid triangle, where it is covered by
the skin, platysma, and fascia; it then
arches downward beneath the
omohyoid, sternohyoid, and
sternothyroid muscles.
 To its medial side are the inferior
pharyngeal constrictor muscle and the
external branch of the superior
laryngeal nerve.
SUPERIOR THYROID ARTERY

38. Branches
 It distributes twigs to the adjacent muscles, and numerous branches to the
thyroid gland, connecting with its fellow of the opposite side, and with the
inferior thyroid arteries. The branches to the gland are generally two in
number. One, the larger, supplies principally the anterior surface; on the
isthmus of the gland it connects with the corresponding artery of the opposite
side. A second branch descends on the posterior surface of the gland and
anastomoses with the inferior thyroid artery.
 Besides the arteries distributed to the muscles and to the thyroid gland, the
branches of the superior thyroid are:
 The infrahyoid branch (or hyoid artery): a small artery that runs along the
lower border of the hyoid bone beneath the thyrohyoid muscle. This artery
connects with the infrahyoid branch of the opposite side. The infrahyoid branch
is a derivative of the second aortic arch.
SUPERIOR THYROID ARTERY

39.  The sternocleidomastoid branch runs downward and laterally across the sheath
of the common carotid artery, and supplies the sternocleidomastoideus muscle
and neighboring muscles and skin; it frequently arises as a separate branch
from the external carotid artery.
 The superior laryngeal artery accompanies the internal laryngeal branch of the
superior laryngeal nerve, beneath the thyrohyoid muscle. This artery branches
from the superior thyroid artery near its bifurcation from the external carotid
artery. Together with the internal laryngeal nerve, it pierces the lateral
thyrohyoid membrane, and supplies blood to the muscles, mucous membrane,
and glands of the larynx, connecting with the branch from the opposite side.
 The cricothyroid artery may contribute to the supply of the larynx. It follows a
variable course either superficial or deep to the sternothyroid muscle. If
superficial, it may be accompanied by branches of the ansa cervicalis, and if
deep, it may be related to the external laryngeal nerve. It can connect with the
artery of the opposite side and with the laryngeal arteries.
SUPERIOR THYROID ARTERY

40.  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.
ASCENDING PHARYNGEAL ARTERY

41.  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
ASCENDING PHARYNGEAL ARTERY

42.  The lingual artery arises from the external
carotid between the superior thyroid artery
and facial artery. It can be located easily in
the tongue.
Structure
 It first runs obliquely upward and
medialward to the greater horns of the
hyoid bone.
 It then curves downward and forward,
forming a loop which is crossed by the
hypoglossal nerve, and passing beneath
the digastric muscle and stylohyoid muscle
it runs horizontally forward, beneath the
hyoglossus, and finally, ascending almost
perpendicularly to the tongue, turns
forward on its lower surface as far as the
tip, under the name of the deep lingual
artery (profunda linguae).
 It also supplies palatine tonsil.
LINGUAL ARTERY

43. Branches
 The deep lingual artery (or ranine artery) is the terminal portion of the
lingual artery after the sublingual artery is given off. As seen in the
picture, it travels superiorly in a tortuous course along the under (ventral)
surface of the tongue, below the longitudinalis inferior, and above the
mucous membrane.
 It lies on the lateral side of the genioglossus, the main large extrinsic
tongue muscle, accompanied by the lingual nerve.
 The sublingual Artery arises at the anterior margin of the hyoglossus, and
runs forward between the genioglossus and mylohyoid muscle to the
sublingual gland.
 It supplies the gland and gives branches to the mylohyoideus and
neighboring muscles, and to the mucous membrane of the mouth and
gums.
LINGUAL ARTERY

44. Other branches
 The suprahyoid branch of the lingual artery runs along the upper
border of the hyoid bone, supplying oxygenated blood to the
muscles attached to it and joining (anastomosing) with its
fellow of the opposite side.
 The dorsal lingual branches of lingual artery consist usually of
two or three small branches which arise beneath the hyoglossus.
They ascend to the back part of the dorsum of the tongue, and
supply the mucous membrane in this situation, the
glossopalatine arch, the tonsil, soft palate, and epiglottis;
anastomosing with the vessels of the opposite side.
LINGUAL ARTERY

45. The facial artery (external maxillary artery in older texts) is a branch of the external
carotid artery that supplies structures of the superficial face.
Structure
 The facial artery arises in the carotid triangle from the external carotid artery a
little above the lingual artery and, sheltered by the ramus of the mandible, passes
obliquely up beneath the digastric and stylohyoid muscles, over which it arches to
enter a groove on the posterior surface of the submandibular gland.
 It then curves upward over the body of the mandible at the antero-inferior angle
of the masseter; passes forward and upward across the cheek to the angle of the
mouth, then ascends along the side of the nose, and ends at the medial
commissure of the eye, under the name of the angular artery.
 The facial artery is remarkably tortuous. This is to accommodate itself to neck
movements such as those of the pharynx in deglutition; and facial movements
such as those of the mandible, lips, and cheeks.
FACIAL ARTERY

46. The branches of the facial artery are:
 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
FACIAL ARTERY

47. Muscles supplied by the facial artery include:
 buccinator
 levator anguli oris
 levator labii
superioris
 levator labii
superioris alaeque
nasi
 levator veli palatini
 masseter
 mentalis
 mylohyoid
 nasalis
 palatoglossus
 palatopharyngeus
 platysma
 procerus
 risorius
 styloglossus
 transverse portion
of the nasalis
FACIAL ARTERY

48.  The occipital artery arises from the
external carotid artery opposite the
facial artery. Its path is below the
posterior belly of digastric to the
occipital region. This artery supplies
blood to the back of the scalp and
sterno-mastoid muscles, and deep
muscles in the back and neck
Structure
 At its origin, it is covered by the
posterior belly of the digastricus and
the stylohyoideus, and the
hypoglossal nerve winds around it
from behind forward; higher up, it
crosses the internal carotid artery,
the internal jugular vein, and the
vagus and accessory nerves.
OCCIPITAL ARTERY

49.  It next ascends to the interval between the
transverse process of the atlas and the
mastoid process of the temporal bone, and
passes horizontally backward, grooving the
surface of the latter bone, being covered by
the sternocleidomastoideus, splenius capitis,
longissimus capitis, and digastricus, and
resting upon the rectus capitis lateralis, the
obliquus superior, and semispinalis capitis.
 It then changes its course and runs vertically
upward, pierces the fascia connecting the
cranial attachment of the trapezius with the
sternocleidomastoideus, and ascends in a
tortuous course in the superficial fascia of
the scalp, where it divides into numerous
branches, which reach as high as the vertex
of the skull and anastomose with the
posterior auricular and superficial temporal
arteries.
OCCIPITAL ARTERY

50. Function
 Muscular branches: supply the digastric, stylohyoid, splenius, and longus
capitis muscles.
 Sternocleidomastoid branch: This branch divides into upper and lower
branches in the carotid triangle. The upper branch accompanies the
accessory nerve to the sternocleidomastoid, and the lower branch arises
near the origin of the occipital artery before entering the
sternocleidomastoid muscle. Occasionally, this branch arises directly
from the external carotid artery.
 Auricular branch: supplies the back of the ear. In many specimens, this
branch gives rise to the mastoid branch, which supplies the dura mater,
diploe, and mastoid air cells. In other specimens, the mastoid artery is a
branch of the occipital artery, rather than the auricular branch.
 Meningeal branch: supplies the dura mater in the posterior cranial fossa
OCCIPITAL ARTERY

51.  Descending branches: This is the largest branch. It descends
on the posterior aspect of the neck, and divides into a
superficial and deep portion. The superficial portion supplies
the trapezius muscle and anastomoses with the ascending
branch of the transverse cervical. The deep portion
anastomoses with the vertebral artery and with the a.
profunda cervicalis, a branch of the costocervical trunk. Thus,
branches of the occipital artery participate in anastamosis
between the external carotid and the subclavian artery,
thereby providing collateral circulation.
 Its terminal portion is accompanied by the greater occipital
nerve.
OCCIPITAL ARTERY

52.  The posterior auricular artery
is a small artery that arises
from the external carotid
artery, above the digastric
muscle and stylohyoid muscle,
opposite the apex of the
styloid process.
 It ascends posteriorly beneath
the parotid gland, along the
styloid process of the temporal
bone, between the cartilage of
the ear and the mastoid
process of the temporal bone
along the lateral side of the
head.
POSTERIOR AURICULAR ARTERY

53.  The posterior auricular
artery supplies blood to
the scalp posterior to the
auricle and to the auricle
itself.
 It located at the
stylomastoid foramen it
gives off its stylomastoid
branch which runs
through the foramen to
supply the tympanic
cavity.
POSTERIOR AURICULAR ARTERY

54.  In human anatomy, the
superficial temporal
artery is a major artery
of the head. It arises
from the external carotid
artery when it bifurcates
into the superficial
temporal artery and
maxillary artery.
 Its pulse is palpable
superior to the zygomatic
arch, anterior and
superior to the tragus.
SUPERFIAL TEMPORAL ARTERY

55. Course
 The superficial temporal artery is the smaller of two terminal branches that bifurcate
superiorly from the external carotid. Based on its direction, the superficial temporal
artery appears to be a continuation of the external carotid.
 It begins in the substance of the parotid gland, behind the neck of the mandible, and
passes superficially over the posterior root of the zygomatic process of the temporal
bone; about 5 cm. above this process it divides into two branches, a frontal and a
parietal.
Relations
 As it crosses the zygomatic process, it is covered by the Auricularis anterior muscle, and
by a dense fascia; it is crossed by the temporal and zygomatic branches of the facial
nerve and one or two veins, and is accompanied by the auriculotemporal nerve, which
lies immediately behind it.
 The superficial temporal artery anastomoses with (among others) the supraorbital
artery of the internal carotid artery.
SUPERFIAL TEMPORAL ARTERY

56.  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
andparietal regions of the scalp respectively
SUPERFIAL TEMPORAL ARTERY

58.  The maxillary artery supplies deep structures of the face. It
branches from the external carotid artery just deep to the neck
of the mandible.
Structure
 The maxillary artery, the larger of the two terminal branches of
the external carotid artery, arises behind the neck of the
mandible, and is at first imbedded in the substance of the
parotid gland; it passes foraward between the ramus of the
mandible and the sphenomandibular ligament, and then runs,
either superficial or deep to the lateral pterygoid muscle, to the
pterygopalatine fossa.
 It supplies the deep structures of the face, and may be divided
into mandibular, pterygoid, and pterygopalatine portions
MAXILLARY ARTERY

59.  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.
FIRST PART OF MAXILLARY ARTERY

60.  The accessory meningeal artery
ascends infront 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
FIRST PART OF MAXILLARY ARTERY

61. within lateral pterygoid muscle
(five branches)
 The second part of the artery
gives two deep temporal
arteries branches to the
temporalis muscle, anterior
temporal, posterior temporal.
 pterygoid branches to the
pterygoid muscles
 the masseteric branch which
passes to the masseter muscle
 the buccal branch which
accompanies the buccal nerve
to supply the structures of the
cheek.
 A small lingual branch
accompanies the lingual nerve
SECOND PART OF MAXILLARY ARTERY

62. 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)
THIRD PART OF MAXILLARY ARTERY

63.  The internal carotid artery is a
major paired artery, one on each
side of the head and neck, in
human anatomy. They arise from
the common carotid arteries
where these bifurcate into the
internal and external carotid
arteries at cervical vertebral
level 3 or 4; the internal carotid
artery supplies the brain.
 The internal carotid arteries do
not supply any structures in the
neck, entering the cranial cavity
via the carotid canal in the
petrous part of
the temporal bone. Within the
cranial cavity, the internal
carotid artery supplies:The brain,
Eyes, Forehead
INternal CArOTID ARTERY

64. Relations of 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.
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.

65.  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.
 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 INternal CArOTID ARTERY

66.  Posterior communicating artery: runs backwards and joins
posterior cerebral artery.
 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
superolateralmargin (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 INternal CArOTID ARTERY

67.  The circle of Willis (also called Willis' circle, loop of Willis, cerebral
arterial circle, and Willis polygon) is a circulatory anastomosis that
supplies blood to the brain and surrounding structures. It is named
after Thomas Willis (1621–1675), an English physician.
 The circle of Willis is a part of the cerebral circulation and is
composed of the following arteries:
 Anterior cerebral artery (left and right)
 Anterior communicating artery
 Internal carotid artery (left and right)
 Posterior cerebral artery (left and right)
 Posterior communicating artery (left and right)
 The middle cerebral arteries, supplying the brain, are not considered
part of the circle
CIRCLE OF WILLIS

68. CIRCLE OF WILLIS
Cerebral angiogram showing an
anterior/posterior projection of the
vertebrobasilar and posterior
cerebral circulation, the posterior
aspect of the circle of Willis and
one of its feeding vessels

69.  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.
CIRCLE OF WILLIS

70.  In human anatomy, the subclavian arteries are paired major arteries
of the upper thorax, below the clavicle. They receive blood from the
aortic arch. The left subclavian artery supplies blood to the left arm
and the right subclavian artery supplies blood to the right arm, with
some branches supplying the head and thorax. On the left side of the
body, the subclavian comes directly off the aortic arch, while on the
right side it arises from the relatively short brachiocephalic artery
when it bifurcates into the subclavian and the right common carotid
artery.
 The usual branches of the subclavian on both sides of the body are
the vertebral artery, the internal thoracic artery, the thyrocervical
trunk, the costocervical trunk and the dorsal scapular artery, which
may branch off the transverse cervical artery which is a branch of
the thyrocervical trunk. The subclavian becomes the axillary artery
at the lateral border of the first rib.
Subclavian artery

71. Subclavian artery

72. Subclavian artery

73.  Capillaries connect arterioles with
venules. They consist only of a
single layer of endothelial cells on a
basement membrane. There is no
media or adventitia. The diameter is
just wide enough for passage of a
red blood cell, therefore flow is very
slow. These features facilitate
exchange of oxygen, nutrients and
other substances between blood and
tissues.
 Capillaries, the smallest and most
numerous of the blood vessels, form
the connection between the vessels
that carry blood away from the heart
(arteries) and the vessels that
return blood to the heart (veins).
The primary function of capillaries is
the exchange of materials between
the blood and tissue cells.
capillaries

74.  Capillary distribution varies with the
metabolic activity of body tissues.
Tissues such as skeletal muscle,
liver, and kidney have extensive
capillary networks because they are
metabolically active and require an
abundant supply of oxygen and
nutrients. Other tissues, such as
connective tissue, have a less
abundant supply of capillaries. The
epidermis of the skin and the lens
and cornea of the eye completely
lack a capillary network. About 5
percent of the total blood volume is
in the systemic capillaries at any
given time. Another 10 percent is in
the lungs.
 Smooth muscle cells in the arterioles
where they branch to form
capillaries regulate blood flow from
the arterioles into the capillaries.
capillaries

75. veins

76.  Veins carry blood toward the heart.
After blood passes through the
capillaries, it enters the smallest
veins, called venules. From the
venules, it flows into progressively
larger and larger veins until it
reaches the heart. In the
pulmonary circuit, the pulmonary
veins transport blood from the
lungs to the left atrium of the
heart. This blood has a high oxygen
content because it has just been
oxygenated in the lungs. Systemic
veins transport blood from the
body tissue to the right atrium of
the heart. This blood has a reduced
oxygen content because the
oxygen has been used for
metabolic activities in the tissue
cells.
Veins

77.  The walls of veins have the same three
layers as the arteries. Although all the
layers are present, there is less smooth
muscle and connective tissue. This
makes the walls of veins thinner than
those of arteries, which is related to the
fact that blood in the veins has less
pressure than in the arteries. Because
the walls of the veins are thinner and
less rigid than arteries, veins can hold
more blood. Almost 70 percent of the
total blood volume is in the veins at any
given time. Medium and large veins have
venous valves, similar to the semilunar
valves associated with the heart, that
help keep the blood flowing toward the
heart. Venous valves are especially
important in the arms and legs, where
they prevent the backflow of blood in
response to the pull of gravity.
Walls of Veins

78.  Post capillary blood flows into venules and then into progressively larger
veins.
 Compared to arteries, veins have larger diameters and thinner
walls. They therefore have larger lumens and contribute capacitance to
the circulation, holding approximately two thirds of all circulating blood.
 The intima and adventitia are similar in structure and function to arteries
but the media is much thinner due to significantly less smooth muscle
and elastic tissue. Veins therefore do not have the same capacity for
elastic recoil and vasoconstriction as arteries. Blood is propelled forward
by contraction of surrounding muscles and pressure gradients created
during inspiration and expiration. Reverse flow is prevented by the
presence of venous valves.
 The flaccid walls of veins predispose them to compression and
penetration by tumour and inflammatory processes.
Walls of Veins

79. Veins of head & neck
Veins of Brain
 Cerebral veins, cerebellar veins, veins of the brainstem, all of
which drain into neighboring venous sinuses.
Venous sinuses
 The dural venous sinuses (also called dural sinuses, cerebral
sinuses, or cranial sinuses) are venous channels found between
the endosteal and meningeal layers of dura mater in the brain.
They receive blood from internal and external veins of the brain,
receive cerebrospinal fluid (CSF) from the subarachnoid space via
arachnoid granulations, and mainly empty into the internal jugular
vein.
VEINs of Brain VEINs of sinuses vEINs of Face and neck

80. VeNOUS SINUSES

81. VENOUS SINUSES

82. Veins of FACE & neck

83. Veins OF FACE & NECK

84.  The internal
jugular vein is a
paired jugular vein
that collects blood
from the brain and
the superficial
parts of the face
and neck. The vein
runs in the carotid
sheath with the
common carotid
artery and vagus
nerve.
INTERNAL JUGULAR Vein

85.  The external jugular vein
receives the greater part of the
blood from the exterior of the
cranium and the deep parts of
the face, being formed by the
junction of the posterior division
of the retromandibular vein with
the posterior auricular vein.
 The posterior external jugular
vein begins in the occipital
region and returns the blood
from the skin and superficial
muscles in the upper and back
part of the neck, lying between
the Splenius and Trapezius.
 It runs down the back part of
the neck, and opens into the
external jugular vein just below
the middle of its course.
EXTERNAL JUGULAR VeiN

86.  The posterior auricular vein
begins upon the side of the
head, in a plexus which
communicates with the
tributaries of the occipital
vein and superficial
temporal veins.
 It descends behind the
auricula, and joins the
posterior division of the
posterior facial vein to form
the external jugular vein.
 It receive the stylomastoid
vein, and some tributaries
from the cranial surface of
the auricula.
POSTERIOR AURICULAR Vein

87.  The occipital vein begins
as a plexus at the
posterior aspect of the
scalp from the external
occipital protuberance
and superior nuchal line
to the back part of the
vertex of the skull.
 From the plexus emerges
a single vessel, which
pierces the cranial
attachment of the
Trapezius and, dipping
into the venous plexus of
the suboccipital triangle,
joins the deep cervical
and vertebral veins.
OCCIPITAL Vein

88.  The facial vein (or anterior facial
vein) is a relatively large vein in
the human face. It commences at
the side of the root of the nose and
is a direct continuation of the
angular vein where it also receives
a small nasal branch. It lies behind
the facial artery and follows a less
tortuous course. It receives blood
from the external palatine vein
before it either joins the anterior
branch of the retromandibular vein
to form the common facial vein, or
drains directly into the internal
jugular vein.
 A common misconception states
that the facial vein has no valves,
but this has been contradicted by
recent studies.
 Its walls are not so flaccid as most
superficial veins.
FACIAL Vein

89.  The superficial temporal
vein is a vein of the side
of the head.
 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.
SUPERFICIAL TEMPORAL Vein

90.  Ophthalmic veins
are veins which
drain the eye.
 More specifically,
they can refer to:
 Superior
ophthalmic vein
 Inferior
ophthalmic vein
OPHTHALMIC Veins

91.  The maxillary veins (internal
maxillary vein in older
sources) consist of a short
trunk which accompanies
the first part of the internal
maxillary artery.
 It is formed by a confluence
of the veins of the pterygoid
plexus, and passes backward
between the
sphenomandibular ligament
and the neck of the
mandible, and unites with
the superficial temporal vein
to form the retromandibular
vein
MAXILLARY Veins

92.  The retromandibular vein
(temporomaxillary vein,
posterior facial vein),
formed by the union of the
superficial temporal and
maxillary veins, descends in
the substance of the parotid
gland, superficial to the
external carotid artery but
beneath the facial nerve,
between the ramus of the
mandible and the
sternocleidomastoideus
muscle.
RETROMANDIBULAR Veins

93.  It divides into two branches:
 an anterior, which passes forward and joins anterior
facial vein, to form the common facial vein, which
then drains into the internal jugular vein.
 a posterior, which is joined by the posterior auricular
vein and becomes the external jugular vein.
 Parrot's sign is a sensation of pain when pressure is
applied to the retromandibular region.
RETROMANDIBULAR Veins

94. FRONTAL Vein
 The frontal vein (v. frontalis) begins on the forehead in a venous
plexus which communicates with the frontal branches of the
superficial temporal vein.
 The veins converge to form a single trunk, which runs downward
near the middle line of the forehead parallel with the vein of the
opposite side. The two veins are joined, at the root of the nose,
by a transverse branch, called the nasal arch, which receives
some small veins from the dorsum of the nose. At the root of the
nose the veins diverge, and, each at the medial angle of the
orbit, joins the supraorbital vein, to form the angular vein.

95.  Occasionally
the frontal
veins join to
form a single
trunk, which
bifurcates at
the root of
the nose into
the two
angular
veins.
FRONTAL Vein

96.  [Standring, S., & Gray, H. (2016). Grays anatomy: the
anatomical basis of clinical practice. Philadelphia: Elsevier.
p.414]
 Gray's Anatomy of the Human Body
 Ashrafian H. Anatomically specific clinical examination of the
carotid arterial tree. Anat Sci Int. 2007 Mar;82(1):16–23.
 Guyton and Hall Textbook of Medical Physiology – 7437 ,9th -
Elsevier
REFERENCES

97. THANK YOU