Gross Anatomy – Head & Neck
-1-
Pawadee: MED 06 – 30114
HEAD & NECK
Muscles
SKULL
upper part: cranium (with cranial cavity inside)
cranial vault (calvanium)

flat bone

the bones are joined by sutures

if the bone is hit hard  fracture (linear
density / straight line)
sutures:

coronal suture

sagittal suture

lamdoid suture
skull bone
 all bones are covered with periosteum
 within the diploe, there are blood
vessels, veins occupying the space 
communicating with veins inside &
outside (inside joins dural venous
sinuses)
 composed of:

outer table overlaid by
connective
tissue
sheet,
which can be removed 
periosteum
with
specific
name,
called
PERICRANIUM

inner table overlaid by
ENDOSTEUM attached to
dura mater of the brain

diploe: spongy bone in
between the outer & inner
tables, which is irregular
space with trabeculae
-
-
scalp (the soft tissue)
 in the front: between the eyebrow, there’s
a flat area on the frontal bone =
GLABELLA
 on the back: there’s superior nuchal line 
a ridge from both mastoid processes on left
& right sides
 boundary between the head above & neck
below & ends medially at a prominence,
called
EXTERNAL
OCCIPITAL
PROTRUBERANCE (INION)
FRONTALIS
OCCIPITALIS
4.
Origin
Skin &
subcutaneo
us of
eyebrow
Insertion
Galea
aponeurotica
Superior
nuchal line
2nd layer: connective tissue layer (dense,
collagen fibre)  fibre & adipose tissue;
there are blood vessels (superficial)
connecting with blood vessels of the 4th
layer (emissary veins), and nerves
3.
3rd layer: aponeurotic layer (tendinous
sheet) - GALEA APONEUROTICA, attached
to muscles:
Action
Temporal
branch CN
VII
Elevates
the
eyebrows
& wrinkles
the skin of
the
forehead
Posterior
auricular
branch of
CN VII
loose
(areolar)
connective
tissue
(subaponeurotic layer)  DANGEROUS
LAYER of skull, which is cotton – like, and
contains blood vessels, especially veins
(EMISSARY VEIN) which will join the diploic
vein and then to the dural venous sinuses
Emissary veins  diploic veins  dural venous sinuses
5.
pericranium (periosteum) – dips inside the
suture, continuous to endosteum (other
areas, except this, can be lifted)
Clinical importance:

if swelling is within one area 
accumulation of blood or fluid between
pericranium & the bone

if swelling crosses the suture to other
parts  collection of fluid above the
pericranium
-
Characteristics of scalp:
 Any infection can spread inter-craniously.

-
Blood vessel walls are adherent to the fibre
(thick collagen fibres)  can’t constrict;
hence, when scalp is wounded no matter
how small the would is, it will bleed
profusely (continuously)
Layers:
layers:
1. 1st layer: skin (superficial): contains many
sebaceous glands and hairy
2.
Nerve
supply

7th layer: pericranium
Gross Anatomy – Head & Neck






-2-
6th layer: temporalis muscle covered by
facia (dense CT sheet) = temporal fascia
5th layer: temporal fascia
4th layer: lateral extension of galea
aponeurotica
3rd layer: external auricular muscles
2nd layer: subcutaneous layer (invades 3rd
layer)
1st layer: skin
Pawadee: MED 06 – 30114
Mandible
 head is articulating place with the depression of
posterior zygomatic bone by hyaline cartilage &
also covered by hyaline cartilage
 between the articulating parts – head of
mandible & mandibular fossa – there is articular
cartilage (disc) inside synovial membrane &
covered by a capsule  all called TEMPORO –
MANDIBULAR JOINT (TMJ)
 tubercle prevents the head from going anteriorly
& prevents dislocation of the head
 pterygoid process composes of:
lateral pterygoid plate (lateral surface)
medial pterygoid plate (medial surface)
FACE
Comprising:
2 orbital cavities
Nasal cavities
3 nose cartilages:
 Septal cartilage – dividing nasal cavity into
two
 Lateral nasal cartilage
 Alar cartilage
Cheek bones
Muscles, supplied by facial nerve
Facial nerves: branches

temporal branch

zygomatic branch

buccal branch

mandibular branch

cervical branch
Injury to facial nerve at the level of PONS segment 
hemifacial paralysis, called BELL’S PALSY.
MUSCLES OF MASTICATION (chewing)
Muscles
Origin
Insertion
Coronoid
process of
mandible
Anterior
border of
ramus of
mandible
Outer surface of the
angle of mandible
Nerve supply
Action
-
TEMPORALIS (fanshaped)
Temporal fossa
MASSETER
MEDIAL PTERYGOID
-
LATERAL PTERYGOID
-
Lower border of
zygomatic arch
Lateral head:
tuberosity of
maxilla
Medial head:
medial surface of
lateral pterygoid
plate
Upper head:
greater wing of
the splenoid bone
Lower head:
lateral surface of
the lateral
pterygoid plate
Medial surface of
angle of mandible
Elevates the mandible
Mandibular
nerve (portio
minor)
Articular disc
(cartilage) & neck of
mandible
MUSCLES OF FACE (muscles of facial expression)
Elevates the mandible
& moves it sideways
Depresses the
mandible & moves
sideways
Gross Anatomy – Head & Neck
-3-
Muscles
Origin
Insertion
FRONTALIS
Skin & subcutaneous of
eyebrow
Galea aponeurotica
CORRUGATOR
SUPERCILII  frowning
muscle
Medial part of
superciliary arch
Skin & superficial fascia
of medial part of
eyebrow
PROCERUS
Nasal bone & upper
part of the lateral nasal
cartilage
Skin & superficial fascia
between the eyebrows
Medial palpebral
ligament
Lateral palpebral
ligament
ORBICULARIS OCULI
* Palpebral part (within the
eyelids)
* Orbital part (margin of
the orbit)
*** Medial palpebral ligament
DILATOR NARIS
Maxilla
Joins compressor naris
of the other side by
means of a thin
aponeurosis that crosses
the bridge of the nose
Ala of the nose
LEVATOR LABII
SUPERIORIS ALAEQUE
NASI
Frontal process of
maxilla (same as
compressor naris)
2 slips: one at the ala of
nose and the other to
the maxilla
Frontal process of the
maxilla
COMPRESSOR NARIS
BUCCINATOR (found at the
cheeks)  blowing muscle
-
Alveolar processes
of maxilla &
mandible opposite
the molars
Pterygomandibular
ligament
Pawadee: MED 06 – 30114
Nerve supply
Temporal branch
facial nerve
Buccal branch of
facial nerve
Action
Elevates the eyebrows &
wrinkles the skin of the
forehead
- Pulls eyebrows medially
- Wrinkles vertically
(between the eyebrows)
- Pulls skin (downwards)
- Produces horizontal
wrinkles
Upper part: Temporal
branch
Lower part:
Zygomatic branch of
facial nerve
Closes the eyeballs
Flattens the nose & closes
the nostrils
Widens the nostrils
elevates the
upper lip
widens the ala of
the nose
Buccal branch of
facial nerve
Presses the cheeks to the
lateral side of the mouth
(important for blowing)
Forms the orbicularis
oris muscle
- Upper part: buccal
branch
- Lower part:
mandibular branch of
the facial nerve
ORBICULARIS ORIS
Mainly from buccinator
muscle, maxilla &
mandible, skin & mucus
membrane of lips
None (as it’s a round
muscle)
LEVATOR ANGULI ORIS
Maxilla below the infraorbital foramen
Skin & orbicularis oris
muscle at the angle of
mouth
Elevates the angle of the
mouth
Skin of upper lip
Elevates the upper lip
LEVATOR LABII
SUPERIORIS
ZYGOMATIC MINOR
ZYGOMATIC MAJOR
RISORIUS  produces a
sarcastic & unpleasant smile
Maxilla above the infraorbital foramen
Zygomatic bone
(cheeks)
Zygomatic arch
Superficial fascia
overlying the parotid
gland (in front & below
the ears)
Closes the mouth (primary
action)
Buccal branch of the
facial nerve
Skin of the angle of the
mouth
Elevates the skin at the
angle of the mouth
Retracts / pulls backward
the skin at the angle of the
mouth
-
DEPRESSOR ANGULI
ORIS
Oblique line of
mandible (a ridge)
Skin & orbicularis oris
muscle at the angle of
mouth
DEPRESSOR LABII
INFERIORIS
Base of mandible
Skin & orbicularis oris of
the lower lip
MENTALIS (small size)
Mandible near
symphysis menti
Superficial fascia of
pectoral region (below
clavicle)
Pulls down the lower lip
Skin of chin
-
PLATYSMA
Mandibular branch of
facial nerve
-
Posterior fibre:
skin at angle of
mouth
Anterior fibre:
lower border of
body of mandible
Pulls down & laterally
the angle of the mouth
Depresses the angle of
the mouth
Elevates the chin
Cervical branch of
facial nerve
-
Posterior fibre: retracts
the angle of the mouth
downwards
Anterior fibre:
depresses the mandible
 thereby opens the
mouth
Gross Anatomy – Head & Neck
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Pawadee: MED 06 – 30114
ORBIT

BOUNDARIES
1. Of ORBITAL OPENING
 Superior =
frontal
(continuous with the forehead)

Lateral
=
=
2.
zygomatic process of
frontal bone
frontal process of
zygomatic bone
Inferior
=
=
zygomatic bone
maxilla

Medial
=
frontal process of
maxilla
lacrimal bone
ethmoid bone
body of splenoid
bone
Of ORBIT
o Superior (roof)
frontal bone
=
orbital plate of
o
Lateral
=
greater wing of
splenoid bone & frontal process
o
Inferior (floor) = zygomatic bone &
orbital plate of maxilla
o
Medial = frontal process of maxilla
lacrimal bone
ethmoid bone
body of splenoid bone
Wall encloses the space, described as cone or pyramidal
shaped; anterior part is large while posterior part is small
which is OPTIC FORAMEN.
Opening serves to transmit outside structure to inside and
vice versa: nerve & blood vessels.
Opening: Foramina

orbital openings

optic canal (foramen)

superior orbital fissure

inferior orbital fissure

zygomatic
–
temporal
&
zygomatiofacial foramen

anterior
&
posterior
ethmoidal
foramina

EXTRINSIC (outside) OCULAR
MUSCLES comprises:
4 recti
2 obliques
These rotate the eyeball in every
direction
2.2)
INTRINSIC OCULAR MUSCLES
(within the eyeball) which is
smooth muscle  involuntary
pupillo – constrictor
pupillo – dilator
ciliary muscle (convergence &
lens thickening)
bone

=
=
=
2.1)
CONTENTS (main content is the eyeball):
1. Eyeball & optic nerve (behind the eyeball):
orbital cavity should be sufficient for eyeball
 there is a rare case that the cavity is smaller
than the eyeball  eyeball bulges (protrudes
outside)
2. muscles
3.
4.
5.
nerves & blood vessels (artery & vein)
fat (adipose tissue) = small amount
lacrimal apparatus = forming tears which are
drained by
overflow to the face
enters the passage of nasal cavity
Wall of the cavity is lined by PERIOSTEUM  lining inside
the cavity, so named PERIORBITA.
Gross Anatomy – Head & Neck
-5-
Upper eyelid
Pawadee: MED 06 – 30114



3 glands:
gland of Zeis  sebaceous gland embedded in
the connective tissue, secreting oily substances
gland of Moll  sweat gland, ciliary gland
embedded in the connective tissue
Tarsal gland  secretes yellow sticky substance

The subtarsal sulcus is where foreign body is
trapped.

Opening of the eye  the upper eyelid does more
in elevating; Orbicularis Oculi muscle contracts
when opening the eye
Muscles
LEVATOR
PALPEBRAL
SUPERIORI
S MUSCLE
Origin
Anterior
part =
upper
lamina 
pierces the
septum
superior &
inserts in
the skin of
eyelid
Posterior
part =
lower
lamina
Insertion
Anterior:
Pierces the
septum
superiorly &
inserts in
the skin of
the eyelid
Posterior:
inserts at
upper
border of
the tarsal
plate
Nerve
supply
Anterior
lamina
(major):
oculomotor
nerve
Posterior
lamina:
sympathetic
nerve

At lacrimal bone, there’s lacrimal sac which
continues down to nasal cavity (at inferior
meatus of nasal cavity)
Cathus of the eye
1. lateral: acute angle
2. medial: round
Circulation of lacrimal apparatus when the eye
is closed
LACRIMAL GLAND
DUCTS
SUPERIOR FORNIX
Action
CONJUNCTIVAL SAC
elevates
the upper
eyelid
opens the
eyes
LACRIMAL LAKE
PUNCTA LACRIMALE
LACRIMAL CANALICULI
LACRIMAL SAC



If oculomotor nerve is injured  dropped
eyelid: eyelid droops or ptosis
If sympathetic nerve is injured  smooth
muscle is paralysed  one eyelid is lower
(also called ptosis).
Depression at the lateral side of the roof is
occupied by LACRIMAL GLAND with 12 ducts
along the superior fornix arranged in one row
(linearly) & opening to superior fornix 
produces tears, coming out from the gland 
duct  conjunctiva via superior fornix
NASOLACRIMAL DUCT
INFERIOR MEATUS OF THE NOSE
Gross Anatomy – Head & Neck
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Pawadee: MED 06 – 30114
EYE
1.
Muscles
Origin
SUPERIOR
OBLIQUE
Medial
border
of the
annulus
of Zinn
INFERIOR
OBLIQUE
Medial
part of
the floor
of cavity

Insertion
Intermediate
tendon (via
fibro
cartilaginous
structure)
Sclera
Nerve
supply
Action
Trochlear
nerve
Moves
the eye
downwar
d
&
laterally
Oculomotor
nerve
Moves
the eye
upwards
&
laterally

2.
Drainage: big veins
superior ophthalmic vein communicates with
facial vein (angular vein tributary)
inferior ophthalmic vein communicates with
pterygoid venous plexus
Both veins go to the medial cranial fossa and join the
cavernous sinus passing through superior orbital fissure.
Tributaries accompany the arteries and join the superior
and inferior ophthalmic veins.

-
Nerves: MOTOR
oculomotor nerve
trochlear nerve
abducens nerve
CHECK LIGAMENT

Nerves: SENSORY
TRIGEMINAL NERVE
Ophthalmic division enters the orbital cavity via superior
orbital fissure, lateral side of cavernous sinus and divides
into:
The purpose of having the check ligament:

to prevent excessive turning of the lateral & medial
recti when they are moved

to limit the movement
Periorbita  tubular sheath  check ligament
At the body of splenoid within the cranial cavity, the
lateral part = optic foramen at the medial cranial fossa,
with dural venous sinus on each side.
Blood vessels from neck go up, called INTERNAL
CAROTID ARTERY at the medial cranial fossa. Gland will
join the optic nerve, called CAVENOUS SINUS at the
lateral side.

1.
2.
3.
4.
5.

LACRIMAL nerve supplying lacrimal gland & skin on
the lateral side of upper eyelid

FRONTAL nerve (near the roof of the orbit) gives out
2 branches to supply the scalp & upper part of head:
 Supraorbital nerve
 Supratrochlear nerve

NASOCILIARY nerve
Supplies the skin of the root of the nose and
medial part of upper eyelid
Mucous membrane of the splenoid & ethmoidal
sinuses (sinusitis occurs at ethmoidal sinus)
Packing material of the orbital cavity
= orbital fat (small amount) to occupy vacant
spaces within the cavity
Branches of Ophthalmic artery
CENTRAL RETINAL ARTERY: enters the
eyeball by joining the optic nerve  divides into
2 to supply the retina. This artery can be blocked
by cholesterol plug causing sudden blindness
(especially in old people).
CILIARY ARTERIES
MUSCULAR BRANCHES
LACRIMAL ARTERY: supplies lacrimal gland
SUPRATROCHLEAR & SUPRAORBITAL
ARTERIES go to scalp supplying the anterior
part of the forehead (anastomosis in the front)
NOSE
Gross Anatomy – Head & Neck
A.
EXTERNAL NOSE

numerous sebaceous glands

components: root, bridge, tip, ala and
nostril (nares)

framework  bones
1.) Upper part
Nasal part of frontal bone (at the
root)
Nasal bones
Frontal processes of maxilla
2.) Lower part
lateral nasal cartilage
alar cartilage
septal cartilage
B.
INTERNAL NOSE

Roof: formed by
1. body of splenoid bone
2. cribriform plate of ethmoid bone
3. frontal bone
4. nasal bone

Floor:
1. palatine process of maxilla
2. horizontal plate of palatine bone

Medial wall: nasal septum formed by
cartilages:
septal cartilage (anteriorly) 
normally
deviated
(not
completely vertical) to the left
or right.
vertical plate of ethmoid bone
(superiorly)
floor at the inferior wall
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Pawadee: MED 06 – 30114


At the wall of middle meatus, there is a bulge (swelling)
which is round due to bulging of ethmoidal sinus  called
BULLA ETHMOIDALIS.
Its lower border has semilunar cleft called HIATUS
SEMILUNARIS; opening of maxillary sinus is at the
posterior part while at the anterior part, it is an opening
of anterior ethmoidal sinus.
FUNCTIONS
warms the inhaling air by blood vessels in the
submucous membrane (when they dilate)
moistens the air by the goblet & mucous glands
in the mucous membrane
cleanses the air by vibrissae (hair of vestibule)
and at the mucous membrane in trapping
foreign bodies / particles secretion
perceives odour at olfactory neuroepithelium
MUCOPURULENT SECRETION

yellowish mucus caused by infection during
having a cold (common)

dilatation of blood vessel

obstruction in nasal cavities by mucous
membrane (stick together)
Bones & cartilages are covered by mucus membrane
(pseudo stratified columnar ciliated epithelium) with
goblet cells, lamina propria.
On mucus membrane, there is capillaries (venous) 
anastomosing in submucous membrane (in nasal cavities)
of septum & splenopalatine arteries  branch supplies
anterior part. The VESTIBULE is lined by special modified
skin of which is stratified squamous epithelium.

Lateral wall: composed of
3 bony SHELF-LIKE projections
 Superior concha  space above it is called
SPLENOETHMOIDAL RECESS
 Middle concha
 Inferior concha
Covered by mucous membrane, continuous to the
mucous membrane of the septum with the same type of
epithelium.

Superior meatus
Middle meatus
Inferior meatus (where tears come out from
lacrimal duct)
EAR
Gross Anatomy – Head & Neck
-8-
Pawadee: MED 06 – 30114
EXTERNAL (OUTER) EAR
O
AURICLE
(PINNA)
EXTERNAL
AUDITORY
MEATUS
Composed of:
1. helix
2. antihelix (bifurcates superiorly)
3. tubercle at the helix
4. lobule (no cartilage)
5. cavum concha
6. cavum
7. incisura intertragica
8. tragus
9. antitragus
-
cartilage covered with skin
gathers sound vibration & transmits to
the inner ear via middle ear




1 inch long
Crooked (almost S-shaped)
Lateral: cavum
Medial:
ear
drum
(tympanic
membrane) at the end
Moves the pinna up & out to see the
ear inside
Wall is partly cartilaginous (lateral 1/3)
and partly bony (inner ½)
Covered by skin (stratified squamous
epithelium)
Glands:
modified
sweat
gland
(ceruminous gland) & sebaceous gland




SENSORY nerve supply for:
Outer surface
External auditory canal
Ear drum
Are
1. Auriculo – temporal nerve (mandibular branch
of trigeminal nerve)
2. Auricular branch of vagus nerve
EXTERNAL AURICULAR MUSCLE

Superior

Anterior
Both are supplied by temporal branch of facial nerve

Posterior – supplied by posterior auricular
branch of facial nerve
O
-
MIDDLE EAR
narrow, oblique in orientation (inclined)
medial to external ear
space
Walls:
1. Roof: petrous temporal bone  thin plate
bone = TEGMEN TYMPANI, which separates
the tympanic cavity from the meninges &
temporal lobe of the brain at the middle
cranial fossa
2.
Floor: formed by thin plate of bone (and
there’s internal jugular vein lying
underneath) which separates the tympanic
cavity from the superior bulb of INTERNAL
JUGULAR VEIN
3.
Anterior: comprising 2 parts

Lower part – thin plate of bone which
separates tympanic cavity from internal
carotid
artery
(surrounded
by
sympathetic
nerve
forming
sympathetic plexus around the artery)

4.
Upper part – there are 2 openings
(canals)
 Upper opening leading to canal
of TENSOR TYMPANI muscle
 Lower opening leading to
EUSTACHIAN
(AUDITORY)
TUBE

runs
forward,
downward, and medially to
reach
the
nasal
cavity
(nasopharynx). It’s partly bony
& partly cartilaginous
 In between is a thin plate of
bone
Posterior wall (behind is the mastoid
process) comprising 2 parts
Upper part – irregular opening
communicates with the ANTRUM of
mastoid  ADITUS (entrance) AD
ANTRUM on its upper part.
The antrum communicates with smaller openings around
and lined by mucous membrane as well as tympanic
cavity.

 Lower part– a thin plate of bone
Its inner surface is cone-shaped projection which is
hollow (apex facing the cavity). Components include:
 pyramid with hollow space which is the origin of a
muscle, called STAPEDIUS muscle (thin muscle).
Tendon from the hollow passes through the apex &
is supplied by a branch of facial nerve.
 facial nerve behind the pyramid
-
5. Lateral wall
Ear drum is found here
It is a circular opening in the bone.
Ear Drum

Oblique (not vertical)

Points downward

From outer surface  concave laterally

Fibrous membrane covered by skin of which is
stratified squamous epithelium

Underneath (inside) is lined by mucus membrane:
pseudostratified
columnar
epithelium
(long
columnar)

Supplied by 2 nerves, which are
Gross Anatomy – Head & Neck
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Pawadee: MED 06 – 30114



Auriculo – temporal nerve (mandibular branch
of trigeminal nerve)
Auricular branch of vagus nerve
Sensitive to pain sensation
Bulge is caused by:
pus (otitis media)
perforation of middle ear  causes pus (may
draw blood out to the outer ear)
Behind the ear drum
-
-
OSSICLES (AUDITORY OSSICLES)
 Form ossicular chain
 Comprising:
1.
2.
3.
MALLEUS (hammer)
round head located above the ear drum at the
posterior & anterior malleolar – folds (backward
& downward of the membrane)  found at
EPITYMPANIC RECESS (space above the
superior surface)
short neck
anterior process
lateral process
mucous membrane binds the handle and the
fibrous membrane
front view:

lateral process points forward

anterior process points to the right side
ligament attaches the anterior process to
anterior wall for support purpose
INCUS (anvil) composed of:
head
long process is parallel to the handle of malleus
short process attached to the posterior wall by a
ligament
body articulates to the head of malleus; such
articulation occupies the epitympanic recess
STAPES (stirrup)
2 limbs
Head
Neck
Base
-
Muscles
TENSOR
TYMPANI
Origin
Canal for
tensor
tympani
Insertion
The root of
handle of
malleus
(turning
around the
hook & goes
laterally)
Nerve
supply
Action
Mandibular
nerve
Tenses
the ear
drum to
prevent
excessive
vibration
of
ear
drum
The facial nerve is just big enough to occupy the small
canal, which is rigid. If there is oedema/swelling of the
nerve, impulses can’t be transmitted to the area supplied
by the nerve, causing BELL’S PALSY.
Within the tympanic cavity, facial nerve branch passes
through the ear drum to the oral cavity, the CHORDA
TYMPANI, to supply the taste buds. Yet, most pass
through stylomastoid… and there are 5 branches given
out from facial nerve.
O
-
VIBRATION of the ear drum causes
 Handle of malleus goes medially as well as the long
process of the incus
 Head of malleus goes laterally
 Head & base of stapes will go medially
 Stapedius muscle dampens excessive vibration of
base of the stapes. If this muscle is paralysed  base
of stapes vibrates excessively  noise is produced
even if it’s only a whisper.
6.
PROCESSUS COCHLEARIFORMIS – a thin plate
of bone extending from the anterior wall to the
medial wall, having a hook-like end
PROMONTORY – a round prominence below the
processus cochleariformis
FENESTRA VESTIBULI (oval window), which is
laterally above the promontory – attached to the
base of stapes by a fibrous tissue, leading to a
canal called SCALA VESTIBULI containing
perilymph
FENESTRA COCHLEA (round window), lying
laterally under the promontory, leads to SCALA
TYMPANI with perilymph
Ridge containing GENICULATE GANGLION of the
facial nerve; hence, it’s called FACIAL CANAL
going posteriorly & downward (behind the
pyramid).
Medial wall comprises
NECK
INNER EAR
membranous & bony labyrinth
canals inside
components:
1. cochlea (snail like) – with Organ of Corti
connecting to CN VIII by spiral ganglion to
cochlear nerve
2. Semicircular
canals
(3
canals:
superior/anterior, posterior, and lateral)
containing fluid inside which moves when
agitated, called endolymph. Perilymph is
outside.
Gross Anatomy – Head & Neck
- 10 -
Boundary
Superior – lower border of body of mandible, mastoid
body
HYOID bone

2 projections posteriorly, known as horns
(cornua)
 Greater cornua
 Lesser cornua
The two triangles are divided by the following muscles.
Muscles
Origin
-
TRAPEZIUS
MUSCLE
-
sternal head:
anterior surface of
manubrium
clavicular head:
medial 1/3 of
superior surface of
clavicle
o medial 1/3 of
superior nuchal line
external occipital
protuberance (inion)
o ligamenturum
nuchae
o C7 spine
o Spine of all the
thoracic vertebrae
(T1-T12)
Insertion
Posterior
Base
Floor
Roof
Nerve
supply
- Lateral part of the
superior nuchal line of
occipital bone
o Posterior surface
of the lateral 1/3
of clavicle
o Medial border of
the acromion and
upper border of
the spine of the
scapula
o Medial end of the
spine of scapula
Posterior border of
sternocleidomastoid muscle
Trapezius muscle
Middle 1/3 of clavicle
o Semispinalis capitis (from spinal
process of the neck muscle)
o Splenius capitis
o Levator scapulae muscle
o Scalenus medius muscle
 Skin (very thing)
 Superficial fascia
 Platysma muscle invading the
fascia
 Investing deep fascia
There are 2 small triangles on the posterior side.
Action
If the 2 heads contract simultaneously  extension
of head at ATLANTO-OCCIPITAL joint & flexion of
cervical
- Mastoid process of
temporal bone
POSTERIOR TRIANGLE

Boundaries
Anterior
Side view
TRIANGLES:
1. Posterior triangle
2. Anterior triangle
Top view
STERNOCLEIDO
MASTOID
MUSCLE
Pawadee: MED 06 – 30114
If contracts only one side e.g. the right  the ear
moves down to the shoulder & head is pulled upward
& laterally to the opposite side
Spinal
accessory
nerve (CN XI)
Shrug the shoulder

Small triangles
Are divided by a muscle, OMOHYOID muscle, which is a
long, narrow muscle
INFRAHYOID MUSCLE – the ONLY muscle under
Hyoid bone
Muscles
OMOHYOID
muscle
Origin
Insertion
Superior
border of
scapula &
the
suprascap
ular
ligament
Inferior border
of body of the
hyoid bone
Nerve
supply
Action
Ansa
cervicalis
Depresse
s (pulls
down)
the hyoid
bone
Composed of 2 bellies: anterior & inferior bellies
connected by intermediate tendon (supported by loop of
fascia at the surface)
Gross Anatomy – Head & Neck
- 11 -
Pawadee: MED 06 – 30114
1. Occipital triangle
-
Boundaries:
Anterior = posterior surface of sternocleidomastoid
Posterior = anterior surface of trapezius
Base = inferior belly of Omohyoid muscle
Floor
o Semispinalis capitis (from spinal process of the neck
muscle)
o Splenius capitis
o Levator scapulae muscle
Scalenus medius muscle
-
2. Supraclavicular triangle
-
Above middle 1/3 of the clavicle
Contents:

brachial plexus at the root of the neck (rami,
trunks, divisions)

nerve to subclavius muscle

suprascapular nerve

superficial cervical artery

suprascapular artery

subclavian artery

external jugular vein
Contents:

occipital artery (the only artery here)

spinal accessory nerve (MOTOR)

great auricular nerve (SENSORY)

lesser occipital (sensory) nerve

transverse cutaneus nerve (sensory) – supplies
Anterior triangle of the neck

supraclavicular nerve (sensory) – divides to supply the
Upper part of pectoral region
The sensory nerves run in superficial fascia as they supply the
skin.
Origins:

great auricular nerve = C2, C3

lesser occipital nerve = C2

transverse cutaneus nerve = C2, C3

supraclavicular nerve = C3, C4
ANTERIOR TRIANGLE
apex pointing downward
base pointing upward
4 muscles
*** All are located above the HYOID bone, so referred to as SUPRAHYOID muscles
Origin
Insertion
Nerve supply
Action
Muscles at the lateral side
Upper border of the
of the tongue (skeletal
HYOGLOSSUS
body & greater horn
Hypoglossal nerve
Depresses the tongue
muscle)  mixes with the
of hyoid bone
muscle of the tongue
Upper border of body of
Mylohyoid line of
Nerve to mylohyoid
- Elevates the hyoid bone
MYLOHYOID
hyoid bone & at a median
mandible
muscle
- Depresses the mandible
raphe
Styloid process of
Junction of greater horn &
STYLOHYOID
Facial nerve
Elevates hyoid bone
temporal bone
body of hyoid bone
Anterior belly: lower
- Posterior belly: facial
Medial surface of
- Elevates the hyoid bone
border of mandible near
nerve
DIGASTRIC
mastoid process of
- Depresses the mandible
the midline (symphysis
- Anterior belly: nerve
temporal bone
(same as mylohyoid)
menti)
to mylohyoid muscle
subdivided into 4 small triangles
Muscles
Gross Anatomy – Head & Neck
- 12 -
Triangles
o
o
1.
Submental triangle
o
o
o
o
2.
Submandibular
triangle – digastric
triangle (below the
chin or mandible)
o
o
o
o
o
o
o
o
3.
Carotid triangle
o
o
Boundaries
anterior = midline of the
neck
posterior = anterior belly of
digastric muscle
base
= hyoid bone (upper
border)
floor
= mylohyoid muscle
roof
=
skin, superficial
fascia, platysma, investing deep
fascia
anterior =
anterior belly of
digastric muscle
posterior = stylohyoid muscle
& posterior belly of digastric
muscle
superior = lower border of
mandible
floor
= hyloglosseus
muscle & mylohyoid muscle
roof
= same as above
superior =
posterior belly of
digastric muscle
inferior
= superior belly of
omohyoid muscle
posterior = anterior border of
the sternocleidomastoid muscle
floor
= middle & inferior
constrictor muscles of pharynx
(surrounded by 3 circular
muscles, which are superior,
middle & inferior constrictor
muscles)
floor
= thyrohyoid
muscle
roof
= same as above
Pawadee: MED 06 – 30114
Contents







common carotid artery and its branches:
internal & external carotid artery
- carotid sinus (dilatation before the branches
are given out)
- carotid body, which is behind the carotid
sinus and supplied by glossopharyngeal nerve





o
4. Muscular triangle
(the so called TRIANGLE
OF NECESSITY)
o
o
o
Anterior
= midline of the
neck
Superior
= superior belly
of omohyoid muscle
Inferior
= anterior border
of sternocleidomastoid
Floor
= sternothyroid,
thyrohyoid, sternohyoid muscles
Roof
= same as
above
submandibular salivary gland & sublingual
salivary gland (little part)
facial artery & vein
hypoglossal nerve
submandibular lymph nodes
nerve to mylohyoid muscle


o
beginning of anterior jugular vein  draining
to external jugular vein
submental lymph nodes (few)







internal jugular vein & tributaries
nerves: CN IX, X, XII
*** carotid sheath, enclosing
1. common carotid artery & branches
including carotid sinus
2. internal jugular vein
3. vagus nerve
ansa cervicalis nerve
emerging from anterior border of
sternocleidomastoid muscle
rami of C1, C2, C3 unite and form one
bundle
internal & external laryngeal nerves
(originated from CN X)
deep cervical lymph nodes

form a chain

in front of sternocleidomastoid

used to detect infection e.g. TB
parotid gland
4 muscles
Deep to the muscles are: larynx, trachea &
thyroid gland.
Same origin: The 2 sterno- (prefix): thyroid
& hyoid
Same insertion: the 2 –hyoid (suffix):
sterno- & thyroAll are supplied by ANSA CERVICALIS
Hemlits manoeuvrer to solve the obstruction
of bolus in the larynx or emergency
tracheostomy if the manoeuvrer doesn’t work
*** All are INFRAHYOID muscles as well as OMOHYOID muscle – on the Posterior triangle
Gross Anatomy – Head & Neck
Muscles
- 13 -
Origin
STERNOTHYROID
STERNOHYOID
Insertion
Oblique line of thyroid
cartilage
Posterior surface of
manubrium
Nerve supply
Action
Depresses the larynx
Depresses the hyoid bone
Ansa cervicalis
Lower border of hyoid
bone
Oblique line of
thyroid cartilage
THYROHYOID
Pawadee: MED 06 – 30114
Depresses the hyoid bone
[But if hyoid bone is fixed,
it elevates the larynx
(opposite to the
Sternothyroid)]
BLOOD SUPPLY
Common carotid artery
NO branch in the neck
Right common carotid artery
(Originates from brachiocephalic artery)
External carotid artery
Superior
thyroid
Artery
lingual
artery
Left common carotid artery
(Originates from the arch of aorta)
Internal carotid artery (NO branch in the neck) – enters cranial arteries
supplying the interior of cranium e.g. brain, hemispheres
facial
artery
ascending
pharyngeal
artery
occipital
artery
posterior
auricular
artery
maxillary
artery
inferior superior external nasal
labial
labial
artery
artery artery
Thyroid gland is
1.
2.
3.
richly supplied by blood from:
superior thyroid artery
inferior thyroid artery
artery from the aorta  called thyroidea ima artery but not a major source
VENOUS DRAINAGE

veins run along with the arteries
superficial
temporal
artery
Gross Anatomy – Head & Neck
o
o
o
o
o
o
o
- 14 -
superficial temporal vein
maxillary vein
posterior auricular vein
occipital vein
– joins the inferior jugular vein
– emerges at the apex of the occipital
triangle
posterior external jugular vein
external jugular vein
internal jugular vein
Superficial temporal vein
Pawadee: MED 06 – 30114
o
o
o
o
o
o
angular vein – a branch of facial vein
facial vein
labial vein: superior & inferior
internal carotid vein
external carotid vein
superficial cervical vein & supraclavian vein
derives from THYROCERVIAL trunk from the
subclavian artery
Maxillary vein
Retromandibular vein
Posterior division
Anterior division
Posterior
Auricular vein
Facial vein
Posterior external
Jugular vein
Internal carotid vein
External jugular vein
Subclavian vein
Anterior jugular vein