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1. The Skull
Areas of Anatomy
1) Gross anatomy: part listing of the human body; studied by region or by system
2) Microscopic anatomy: histology
3) Developmental anatomy: embryology
4) Functional anatomy: physiology
5) Radiographic anatomy: study of the human body using x-rays
- Anatomical position: body upright, with palms and hands facing forward, and feet close together
- Body defining planes:
1) Coronal plane: passes from one side to another dividing the body into anterior and posterior parts
2) Sagittal plane: passes from front to back dividing the body into right and left parts. Mid-Sagittal
is when the right and left parts are exactly equal, the dividing line passing in the middle
3) Transverse plane: passes from side to side and front to back horizontally dividing the body into
superior and inferior parts
- Relative anatomical terms:
o Anterior = ventral = front
o Posterior = dorsal = back
o Superior = cephalic = upper
o Inferior = caudal = lower
o Proximal = closer to origin
o Distal = away from origin
o Superficial = close to surface
o Deep = away from surface
- Movement of body parts :
o Extension = returning part to normal position
o Flexion = bending body part ( forward movement of body part)
o Abduction = moving part away from position; laterally
o Adduction = moving part closer to body; medially
o Rotation = along 1 axis, its either external (lateral) or internal (medial)
o Circumduction = combined complex movement
o Protrusion = forward movement of the mandible
o Retraction = moving mandible back to its place
- Basic body tissues and parts:

2. o Tendons: fibrous connective tissue band which originates from the skeletal muscle and
inserts into the bone.
o Aponeurosis; fibrous connective tissue that forms a flat sheet. it lies between parts of the
body
o Fascia: a covering structure which surrounds and divides large spaces in the body to smaller
compartments
o Borsa: synovial structure that is found between, tendon-tendon, tendon-bone, it produces
synovial fluid for lubrication
Body Systems: Note: nerves are either
sensory or motor or both
1) Nervous system:
a. Central nervous system: brain and spinal cord
b. Peripheral nervous system: cranial nerves (12 pairs arise from the brain), spinal nerves (31
pairs arise from spinal cord) and autonomic nervous system. Nervous and endocrine
systems are responsible
Spinal cord:
for body function.
o Contains dorsal horn, which is located at the dorsal aspect. It is completely sensory
o Contains ventral horn, located at the ventral aspect. It is completely motor
o Dorsal root arises from dorsal horn while ventral root arises from ventral horn
o Dorsal root passes through dorsal root ganglion, ventral root passes through ventral root
ganglion
o After passing through ganglia they form together spinal nerves
o They then divide into ventral and dorsal rami both being mixed Sensation
(Sensory and motor)
General Special
Pain Vision
2) Mucoskeletal system : has 3 main components
a. Joints: where 2 or more bones come together Touch Taste
i. Bony joints: immovable (pelvis, sutures) Temprature Hearing
ii. Relatively movable: fibrocartilage
iii. Freely movable: synovial Pressure Smelling
b. Muscles: smooth, skeletal, cardiac
i. Skeletal: it is for movement, it is named based on
1. Function: extensor, abductor, etc
2. Shape: deltoid
3. Size: maximus, minimus
4. Attachment: temporalis
5. Length: short, long
c. Bones: 2 types
i. Axial skeleton: lies in the center (ex: pelvis)
ii. Appendicular: has similar right and left parts

3. Bone is classified according to being:
Short
Long (ex: arm & forearm)
Flat (ex: skull)
Irregular (vertebrae)
Pneumatic: contains air cavities
Sesamoid: bone that lie in the tendon (ex: patella)
Synovial Joints
Synovium is the membrane that produces the synovial fluid, it is important for lubrication and
reduction of friction.
It is a weak structure, thus surrounded by fibrous joint capsule to prevent it’s separation during
movement.
Joint stability is achieved by:
It is not necessary
1) Joint capsule to have all the
2) Shape of the bone forming the joint structures to
3) Ligaments
achieve stability
4) Muscles around the joint
The skull is part of the axial skeleton
It is composed of 22 bones:
- 21 firmly joined together by sutures
- Mandible: a single movable bone which articulates with the skull at the TMJ (a synovial
joint)
The 22 bones are either single or paired (one on each side)
Note:
6 Single Bones 8 Paired Bones
Mandible Maxillary The hard palate is formed by
Frontal Nasal the Maxillary bones (anterior
Occipital Zygomatic 1/3) and the palatine bones
Sphenoid Inferior Nasal conchae (posterior 2/3)
Ethmoid Parietal
Vomer Temporal
Lacrimal
Palatine
Bones are either facial or cranial

4. Views of the Skull
Outside views
Superior
Inferior = Basal
Posterior = occipital
Anterior = Frontal
Lateral = Temporal
1) Anterior View: frontal
Bones present in this view are: frontal, nasal, lacrimal, maxillary, mandibular, zygomatic,
vomer, inferior conchae
a. Frontal bone: convex in shape, forms forehead
b. Orbit: opening of the eyes. Has 4 orbital margins
i. Supraorbital margin: formed by frontal bone
ii. Medial orbital margin: formed by fontal (superiorly), maxilla (inferiorly)
iii. Infraorbital: formed by zygoma, and maxilla
iv. Lateral orbital margin: frontal (superiorly), zygomatic (inferiorly)
Landmarks of the orbit:
1) Supraorbital notch/foramen: in the superior orbital margin for transmission of vessels
and nerves. Painful if pressed on
2) Superciliary arch: a bony elevation lying above the supraorbital margin. (eyebrows
lie exactly above the margin)
3) Glabella: hairless region between the supraciliary arches. Clinical significance: 1-
skin turgidity can be measured in patients suspected of dehydration. 2- glabellar
reflex, in which a person’s forehead is taped several time and the subject blinks, if the
blinking persists, which is called Myerson’s sign, being an early symptom of
Parkinson’s disease, dementia and neurological disorders
4) Nasion: root of the nose, depressed area between the 2 orbits

5. 5) Infra-orbital foramen: located in the anterior surface of the maxilla on the same line
vertically with the supra-orbital foramen
6) Anterior nasal apertures: (nasal openings), their boundaries are the 2 nasal bones
superiorly, maxillary bone laterally, maxillary bone inferiorly
7) Zygoma: 2 bones below the orbit
8) Inferior and middle nasal conchae (superior are hidden and not seen in frontal view)
Superior and middle nasal conchae are part of the ethmoid but the inferior nasal
concha is a separate bone
9) Alveolar processes
a. Of the maxilla, have sockets that carry the maxillary teeth
b. Of the mandible, containing sockets for the mandibular teeth

6. 2) Lateral View: also called the temporal view
Landmarks of the lateral view:
a. Anterior nasal spine: union of 2 maxillary bones at the lower border or the anterior nasal
apertures
b. Nasal septum: divides nasal cavity vertically into 2 cavities
nasal septum is divided into 3 parts: anteriorly nasal cartilage, inferiorly vomer,
superiorly perpendicular plate of the ethmoid.
c. Lateral orbital margin
d. Temporal lines: they are either superior and inferior or one single line
e. Zygomatic arch: formed by the zygomatic process of temporal bone and the temporal
process of the zygomatic bone
f. Temporal fossa:
i. Region limited by temporal lines superiorly and zygomatic arch inferiorly
ii. Formed by: frontal, parietal, greater wing of sphenoid and temporal bones

7. iii. Gives rise to temporalis muscle
iv. Pterion:
1. H-shaped region
2. Lies above anterior branch of middle meningeal artery
3. Very thin bone, easily fractured leading to injury of underlying artery
which will result in intercranial, epidural or extradural hematoma. May
compress the brain tissue
g. External acoustic meatus: auditory tube, posterior to the TMJ
h. Mastoid process:
i. Conical bony projection behind ear, pulpable area
ii. Contain air filled cells, function in?????
iii. Provides attachment to muscles and ligaments???????
i. Styloid process: deep, not pulpable, attaches muscles and ligaments (styloid apparatus)
j. Paranasal air sinuses: air filled cavities which open into the nose
i. Frontal
ii. Maxillary
iii. Sphenoid
iv. Ethmoid
3) Superior View: calvaria
Bones present are: frontal bone, right and left parietal bones, occipital bone
Landmarks:
a. Coronal suture: between frontal bone and the 2 parietal bones
b. Sagittal suture: between the 2 parietal bones
c. Lambdoid suture: between the 2 parietal and the occipital bones
d. Bregma : meeting point of coronal and sagittal sutures
e. Lambda: meeting point of lambdoid and sagittal sutures
f. Parietal foramen: in the parietal bones, for transmission of emissary veins (veins which
connect venous blood from the outside to the inside)
Neonatal skull:
- Sutures are not well joined together
Sagittal suture looks like an arrow
Metopic suture: lies between the 2 frontal bones and ossifies by the age of 5
Anterior fontanelle: unossified “bregma”, ossifies by the age of 18 month to form
bregma
Posterior fontanelle: unossified “lambda”, ossifies by the age of 9 month to form
lambda
 They function to assess the intercranial pressure by palpation (bulge if high
and depress if low pressure)

8. 4) Posterior view:
- Landmarks of the posterior view:
Sagittal Suture
Lambdoid Suture
External Occipital protuberance: a projection in the squamous part of the occipital
bone
Nuchal lines: superior and inferior extending from the lateral part of the external
occipital protuberance
Temporal Bone
Parietal Bone
Occipital Bone
Maxillary Bone
Mandibular Bone

9. 5) Inferior view:
12 pairs of cranial nerves which pass through the openings in the inferior view
I. Olfactory
II. Optic
III. Occulomotor
IV. Trochlear
V. Abducent
VI. Trigeminal Muscles of mastication:
i. V1 ophthalmic
ii. V2 Maxillary 1) Temporalis
iii. V3 Mandibular 2) Masseter
VII. Facial 3) Medial pterygoid
VIII. Vestibulochoclear 4) Lateral pterygoid
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal
Landmarks of the inferior view:
1) U-Shaped maxilla

10. 2) Hard palate: separates oral from nasal cavity, anterior 2/3 formed by maxilla, posterior 1/3 formed by
the horizontal plate of the palatine bone
3) Palatine process of the maxilla
4) Sphenoid bone
a) Greater wing
b) Lesser wing
c) Medial and lateral pterygoid processes
d) Body of the sphenoid
5) Pterygoid fossa: lies between the medial and lateral pterygoid processes and gives attachment to
pterygoid muscles
6) Infratemporal fossa: exposed by removal of the zygomatic arch and the mandible, it’s boundaries are:
a) Anteriorly: maxilla
b) Posteriorly: styloid process
c) Laterally: zygomatic arch or ramus of the mandible
d) Medially: lateral pterygoid plate
7) Posterior nasal openings: nasal choanae, communicates the nasal cavity to the oropharynx it’s
boundaries are:
a) Superiorly: body of the sphenoid
b) Inferiorly: horizontal plates of the palatine bone
c) Medially: vomer
d) Laterally: medial pterygoid processes
8) Temporal bone:
a) Zygomatic process
b) Squamous part
c) Petrous part
d) Styloid process
e) Mastoid process
f) Tympanic plate

11. 6) Cranial base of the skull:
- Contains several openings and foramina through which the nerves and blood vessels pass
- Occipital condyle: bony mass on each side of foramen magnum and articulates with atlas (C1)
to form atlantooccipital joint
Opening position Structures passing through
Cribriform plate Part of the Ethmoid bone Olfactory bulb/fibers (from olfactory
nerve I)
Optic canal At root of lesser wing Optic nerve II
Ophthalmic artery
Supraorbital Communicates the orbital canal and middle Oculomotor nerve III
fissure cranial fossa, between lesser and greater Trochlear nerve IV
wings of sphenoid Ophthalmic nerve V1
Abducent VI

12. Superior and inferior ophthalmic veins
Foramen In greater wing of sphenoid, communicates Maxillary nerve V2
Rotundum middle cranial fossa with pterygopalatine
fossa
Foramen Ovale In greater wing of sphenoid , communicates Mandibular nerve V3
middle cranial to Infratemporal fossa
Foramen Between body of the sphenoid and Petrous Greater Petrosal nerve
lacerum part of temporal bone (a branch of the facial nerve VII, which
then leaves through the stylomastoid
foramen)
Foramen In greater wing of the sphenoid, Anterior branch of the middle
spinosum communicates middle cranial fossa to meningeal artery
Infratemporal fossa
Carotid canal In Petrosal part of temporal bone, opens Internal carotid artery
into posterior wall of foramen lacerum Sympathetic nerve plexus
Internal acoustic Intracranially, in the posterior surface of the Facial nerve VII
meatus Petrous part of the temporal bone Vestibulocochlear nerve VIII
Stylomastoid Between styloid and mastoid processes of Facial nerve VII (pure motor branch)
foramen the temporal bone
Jugular foramen Between occipital bone and Petrous part of Glossopharyngeal IX
temporal bone Vagus nerve X
Accessory nerve XI
Internal jugular veins
Sigmoid sinus
Posterior meningeal artery
Inferior Petrosal venous sinus
Condylar canal Anterior to occipital condyle Emissary veins
Hypoglossal Posterior to condyle Hypoglossal nerve XII
canal
Foramen Occipital bone Spinal root and its covering meninges
magnum Spinal root accessories
Vertebral artery
The spinal root arises from the spinal cord Vertebral
then enters the skull through foramen arteries supply
magnum to join with the cranial root and posterior part of
leave jugular foramen as accessory nerve the brain

13. Cranial Fossae
1) Anterior cranial fossa:
Boundaries: from Squamous part of the frontal bone to the lesser wing of the sphenoid
Contents: frontal lobes of brain
Floor is formed by:
Cribriform plate of the Ethmoid bone , it lies between the nasal cavity and the
anterior cranial fossa (part of floor of ACF and roof or nasal cavity)
Crista galli: upward bony projection (from cribriform plate) which attaches to falx
cerebri
Orbital plate of frontal bone
2) Middle cranial fossa:
Boundaries: lesser wing of sphenoid anteriorly to petrous part of temporal bone
posteriorly
It is composed of 2 lateral portions, a central portion formed by superior surface of the
body of the sphenoid

14. The central portion includes sella turcica (also called the hypophyseal fossa or pituitary
fossa). Tuberculum sellae: anterior limit of sella turcice. Dorsum sellae: posterior limit of
sella turcica
Floor:
Greater wing and body of sphenoid
Squamous part of temporal bone
Part of Petrous part of temporal bone
3) Posterior cranial fossa:
- Boundaries: upper border of Petrous part of temporal bone anteriorly and Squamous part of
occipital bone Posteriorly
- Contains: the cerebellum
- Landmarks:
Internal occipital protuberance: projection in the inner surface opposite to the
external occipital protuberance
Sigmoid sulcus: S-shaped sulcus, contains the sigmoid venous sinus
Sulcus for Transverse Sinus: contains the transverse venous sinus
Before the facial nerve enters the internal
acoustic meatus, it gives a branch to the
greater petrosal nerve, which then leaves
through foramen lacerum. The facial nerve
leaves the Stylomastoid foramen as pure
motor
Facial nerve Great petrosal Stylomastoid
IAM Foramen lacerum Facial
foramen
Meninges
They are 3 membranes which surround the brain and spinal cord.
I. Pia mater: delicate layer directly attached to the brain and spinal cord
a. Subarachnoid space: space that lies between the Arachnoid mater and the Pia mater.
Contains CSF (cerebrospinal fluid) which act as a cushion to protect the brain and spinal
cord
II. Arachnoid mater: transparent layer, which lies over the Pia mater. It shows trabeculations
(arachnoid granulation villi), which function in the drainage of the CSF and the venous blood in
the venous sinuses
a. Subdural Space: contains blood vessels
III. Dura mater: tough layer which lies over the Arachnoid mater
Cranial dura: consists of periosteal layer (endosteal layer) which is the lining of the skull
bone, and the real dura mater, which is the tough fibrous layer
a. Epidural Space: lies between dura mater and bone. Contains blood vessels

15. Dura Mater
The Dura mater is separated into 2 layers called the dural folds or projections, they separate different
brain hemispheres.
I. Falx Cerebri:
a. separates the 2 cerebral hemispheres
b. Double layer of dura which separate the 2 cerebral hemispheres
c. Attached anteriorly to crista galli
d. It has 2 borders:
i. Upper: superior Sagittal sinus lies in it
ii. Lower border: inferior Sagittal sinus lies in it
II. Falx Cerebelli:
a. separates the 2 cerebellar hamispheres
III. Tentorium Cerebelli:
a. separates the cerebellum from the occipital lobes of the cerebrum
b. Forms a tent over the posterior cranial fossa

16. IV. Diaphragm Selli:
a. Very small dural projection that form the roof of sella turcica
b. Has an opening in the middle for the stalk of the pituitary gland
Dural Venous Sinuses
Venous channels which lie between the 2 layers of the Dura mater. They lack valves and smooth muscles
in their walls, as blood flows with gravity.
Single Sinuses Paired Sinuses
Superior Sagittal Venous Sinus Transverse Venous Sinus
Inferior Sagittal Venous Sinus Sigmoid Venous Sinus
Straight Sinus Cavernous Venous Sinus
Superior Petrosal Sinus
Inferior Petrosal Venous Sinus
Single Sinuses
I. Superior Sagittal venous sinus:
a. In the upper border of the falx cerebri
b. Runs upwards and backwards ending at the internal occipital protuberance
II. Inferior sagittal venous sinus:
a. In the lower border of the falx cerebri
b. Joins with the great cerebral vein to form the straight sinus, which runs upwards and
medially
III. Straight Sinus:
a. Formed by the union of the great cerebral vein and the inferior petrosal venous sinus
b. Runs at the meeting point of the tentorium cerebella and falx cerebri
c. Ends at the internal occipital protuberance
Paired Sinuses
I. Transverse Sinus:
a. Right transverse sinus: continuation of the superior Sagittal sinus
b. Left transverse sinus: continuation of the straight sinus
c. Passes lateral to the internal occipital protuberance on both sides
II. Sigmoid Sinus:

17. a. Continuation of the transverse sinus
b. Ends at the jugular foramen forming the jugular bulb which then continues as internal
jugular vein
III. Cavernous Sinus:
a. Cave like, lies in body of the sphenoid
b. It has a special importance as some important structures pass through it
i. Vessels: internal carotid artery
ii. Nerves: Occulomotor III, Trochlear IV, Abducens VI, V1 & V2 of trigeminal V
c. Infection in the dangerous zone (angle between mouth and eye) can easily transmit it into
the brain by the following pathway:
Facial Vein pterygoid venous plexus
inferior ophthalmic vein cavernous sinus
Any problem in the cavernous
sinus affects movement of
eyeball, sensation of the face,
blood supply to the brain
Cavernous sinus receives blood from superior
and inferior ophthalmic vein. Before entering
the sinus, the inferior ophthalmic vein
communicates with the pterygoid plexus

18. IV. Superior petrosal sinus:
a. Arises from the upper posterior part of the cavernous sinus
b. Runs in the upper border of the petrous part of the temporal bone, to joining the sigmoid
venous sinus
V. Inferior petrosal sinus
a. Arises from lower part of cavernous sinus
b. Joins internal jugular vein, from outside the skull after passing through the jugular
foramen
c. It’s the only venous sinus that leaves the skull with the venous blood
Individual Bones of the Skull
1) Maxilla: a paired bone which has 4 processes and 4 surfaces
- 4 surfaces :

19. Superior: it separates the orbital cavity from the maxillary air sinuses
Anterior: facial
Posterior: forms anterior limit of infratemporal fossa
Medial (nasal): forms lateral wall of the nasal cavity
- 4 processes:
Frontal: joins the frontal bone to form the medial orbital margin
Zygomatic: joins the zygoma to form the infra orbital margin
Alveolar: Contains sockets for upper teeth
Palatine: joins palatine bone to form the hard palate
- Articulations of the maxilla: frontal, nasal, zygomatic, inferior nasal concha, palatine bone,
ethmoid, maxilla
- Maxillary nasal sinuses are located in the medial (nasal) process. It is one of the biggest
sinuses and functions in resonance of voice and lightening of weight of skull
2) Mandible: A single bone, horseshoe shaped, which is composed of a body and 2 rami
- The body: composed of 2 surfaces (inner and outer) and 2 borders (superior and inferior)
Outer surface:
 Mental protuberance: lies in the midline
 Mental tubercle: lies on both sides of the protuberance

20.  Mental foramina: located below the apices of the premolar-molar. Can be
used to determine the age of a person as it is closer to the inferior border in
infants and closer to the superior border in elderly people, in adults it lies in
the middle. (the change in position is relative as the bone is not completely
grown in infants and is resorbed in elderly)
 Oblique line: also called the external oblique ridge, extends from mental
foramen to the anterior border of the ramus
Inner surface:
 Superior and inferior mental spines (genial tubercles): 4 projections which
lie in the midline which give attachment to:
Superior: genioglossus muscle
Inferior: geniohyoid muscle
 Mylohyoid line: gives attachment to mylohyoid muscles which are 2 muscles
join to form the floor of the mouth

21.  Sublingual fossa: a depression which lies above the mylohyoid line. Contains
the sublingual salivary glands
 Submandibular fossa: a depression which lies below the mylohyoid line.
Contains the submandibular salivary gland
 Digastric fossa: located below the genial tubercle
- The Ramus: each has 2 surfaces(medial and lateral),2 processes (anterior/coronoid and
posterior/condylar) and 2 borders (anterior and posterior)
- Ramus meets the body to form the angle of the ramus
Surfaces:
 Lateral: smooth except where it gives attachment to the massetter muscle
 Medial surface:
Mandibular foramen: opens to the mandibular canal which ends at
the mental foramen, transmitting the inferior alveolar nerve and
blood vessels. Mental nerve is the continuation of the inferior
The ramus is sandwiched by the
massetter muscle from outside
and medial pterygoid from the
inside

22. alveolar nerve, supplies lower teeth and lip, thus anesthesia is given
in it.
Lingula: bony projection, lies anterior to mandibular foramen.
Provides attachment to ligaments.
Rough region in the lower part of inner surface, gives attachment to
the medial pterygoid muscle.
Processes:
 Coronoid/anterior: gives attachment to temporalis
 Condyle/posterior:
Head: articulates with mandibular fossa of temporal bone forming
TMJ
Neck : provides attachment to capsule of TMJ
3) Sphenoid Bone: a single bone has the shape of a butterfly.
It is composed of:
- Body
- 2 greater wings
- 2 lesser wings
- 2 pterygoid processes
Body:
o Has 2 surfaces:
 Superior: forms sella turcica/pituitary fossa/
 Inferior: forms upper margin of coanae and upper border of pharynx
o Sphenoid air sinuses:
 Upper border: sella turcica
 Lower border: roof of pharynx
 Visible in the anterior view
Greater wing of sphenoid:
o Has 4 surfaces:
 Cranial surface
 Lateral surface: temporal
 Inferior : infratemporal , roof of infratemporal fossa
 orbital
Between the lesser and greater wings lies the superior orbital fissure
Pterygoid plates/processes:
 Medial and lateral processes/plates in between them lies the pterygoid fossa
 The pterygoid fossa provides attachment to the medial and lateral pterygoid
muscles
 The pterygoid fossa can be seen only in the posterior view

23.  Optical canal is located at the roof of lesser wing and above superior orbital
fissure, while rotundum is below superior orbital fissure
 Above the pterygoid plate lies the pterygoid canal (transmits the pterygoid
nerve)
 Ovale, rotundum and spinosum are present on the greater wing but are not
visible in the anterior or posterior view.
Articulations of the sphenoid bone:
o Palatine bone, ethmoid, nasal bone, temporal , vomer, frontal, parietal, occipital,
zygoma, maxilla
4) Ethmoid: single bone, lies between the 2 orbits
- it is also located in:

24. o upper part of nasal cavity
To differentiate between
medial and lateral views of o roof of nasal cavity
the nasal cavity: in the medial o perpendicular plate of the ethmoid, forms part of the nasal septum
o lateral wall of ethmoid forms the medial wall of the orbit
view the septum is present
o medial wall of the ethmoid forms the lateral wall of the nasal cavity
- the labyrinth contains air filled cavities (ethmoidal air cells), each has
o medial/ nasal plate
 has 2 projections: superior and middle nasal conchae
o lateral/orbital plate
- cribriform plate separates the nasal cavity from the anterior cranial fossa

25. 5) Frontal Bone: single bone, developed from 2 halves, which are separated by the metopic suture
(ossifies at the age of 5 years)
- It is composed of 2 processes:
o Maxillary: articulates with the maxilla to form medial orbital margin
o Zygomatic: articulates with the zygoma to form lateral orbital margin
- In the upper orbital margin lies the supraorbital foramen/notch
- Supraciliary arch: lies above the supraorbital margin (below the eyebrow)
- Glabella: hairless area between the supraciliary arches
- Frontal nasal sinuses: 2, which drain the nasal cavity
o They are lined by the same epithelium of the nasal cavity
o They function in:
 Weight reduction
 Sound resonance
- Squamous part:
o Forms the vault and forehead
o Forms the floor of the anterior cranial fossa
o Forms the roof of the orbital cavity
- Foramen cecum: lies anterior to crista galli, for transmission of emissary veins
6) Temporal Bone: paired bone, on the lateral sides of the skull, composed of 5 parts
Squamous, petrous, mastoid, styloid, tympanic
- Squamous:
o Vertical flat part
o Forms part of the floor of the temporal fossa
o Has the zygomatic process which articulates with the zygoma to form
the zygomatic arch
o Mandibular fossa: inferior to zygomatic process. Site of articulation with
the condyle
- Tympanic plate:
o Anterior limit of external acoustic meatus
Chorda tympani
- Mastoid process:
exits between the
tegmen tympani o Conical, palpable bony projection, lies behind the ear
and anterior edge o Contains air filled cavities (mastoid air cells)
of tympanic plate o For resonance of sound
o Gives attachment to sternocleidomastoid muscle and posterior belly of
Digastric muscle
o Gives attachment to ligaments
- Styloid process:
o Deeply seated, non-palpable
o This downwardly projected bony process
o Gives attachment to:

26.  Stylohyoid muscle
 Stylopharyngeal muscle
 Styloglossus muscle
 Stylohyoid ligament
o Stylomastoid foramen lies between the styloid and mastoid processes
- Petrous part:
o Sometimes called petromastoid (closely related to mastoid)
o Hard rock like bony part containing important structures
 Ear cavity (through internal acoustic meatus)
 Carotid canal (transmits internal carotid artery and sympathetic
plexus)
 Facial nerve
 Vestibulocochlear nerve
7) Occipital bone: single flat bone, forms posterior part of the skull and part of the base of the skull
- Squamous part: The curved, expanded plate behind the foramen magnum
o Superior and inferior nuchal lines which project laterally from the
external occipital protuberance
o Internal occipital crest: projection which lies posterior to the foramen
magnum (internally)
o Internal occipital protuberance (internally)
o Has transverse groove for transverse sinus (internally)
- Basilar part: the thick part in front of the foramen magnum,

27. o Projects anteriorly, forming part of the roof of the pharynx (pharyngeal
tubercle)
- Articulates with part of the sphenoid
8) Nasal bone: a paired bone
- Join in the midline
forming part of the
roof of the nasal cavity
9) Zygomatic bone: paired bone, forms the
prominence of the cheek

28. - Articulates with frontal, maxillary, greater wings of sphenoid and temporal bone
10) Lacrimal bone: paired bone
- Forms part of the medial wall of the orbit
- Nasolacrimal duct: a canal that connects the orbit to the nasal cavity (for the
drainage of tears)
11) Palatine bone: paired bone, L-shaped

29. - 2 plates:
o Horizontal: forms the posterior third of the hard palate and the
projecting nasal crest forms part of the nasal septum
o Perpendicular plate: forms lateral wall of the nasal cavity
12) Inferior nasal conchae: paired bones
- Attached to lateral wall of the nasal cavity
- A fragile bone
- Increases surface area of nasal cavity
- Lined by mucous membrane
13) Vomer: single bone, a thin deep plate
- Articulates with
o Maxilla
Nasal septum: vomer, o Ethmoid
septal cartilage, o Sphenoid
perpendicular plate of o Septal cartilage
the ethmoid (inferiorly)
Face

30. The face extends from the hair to the lower border of the mandible and from the ear to the ear
Contents of the face:
- Skin: includes hair follicles, sweat glands and sebaceous glands
- Connective tissue: has superficial fascia only, no deep fascia
- Muscles: mastication and facial expression muscles
- Blood Vessels: arteries and veins
- Glands: parotid and submandibular glands
- Nerves: trigeminal and facial nerves
Muscles of facial expression:
- Responsible for expression
- Control size of facial openings (each has sphincter/closes
o Mouth
o Nose
o eyes
- Arise from facial skeleton and are inserted into skin
- Arise from 2nd branchial arch
- Supplied by facial nerve
Muscles of the Eyes:
Name of Muscle Sphincter/Dilator Function
Whole muscle: helps move tears towards midline of
Orbicularis oculi
face
Peripheral/orbital part sphincter
Orbital part: forceful closure
Central/palpebral part
Palpebral part:gentle closure
Elevates eyebrows, and wrinkles forehead, opens the
Frontalis Dilator
eye
Levator palpebrae Elevates upper eyelid, only muscle supplied by the
Dilator
superioris occulomotor nerve
Muscles of the nostrils:
Name of Muscle Sphincter/dilator Function
Dilator naris Dilator Dilates opening of nose
Compressor naris Sphincter Closes opening of nose

31. Muscles of the Mouth:
Name of muscle Sphincter/dilator function
Orbicularis oris Sphincter Arises from the maxilla and
mandible, brings the 2 lips
together (whistling action)
Zygomaticus major and minor Dilator Elevates the angel of the mouth
Levator labii superioris Dilator Elevates the upper lip upwards
Levator anguli oris Dilator Lies between the zygomaticus
major and minor, elevates angel
of mouth
Depressor labii inferioris Dilator Moves lip downwards
Depressor anguli oris Dilator Moves angel of mouth
downwards
Mentalis Dilator Depressing of chin
Resorius Dilator Moves angle of mouth
horizontally
Platysma Dilator Depression of lower lip,
tightening of the skin of the neck
Muscles of the Cheek:

32. Buccinator Muscle: lie between massetter and angel of mouth
- Anterior fibers mix with orbicularis oris muscle
- Pierced by the duct of the parotid gland
- Function
o Blowing
o Pushing food out of the vestibule into the oral cavity proper
Blood Supply of the Face
1) Arterial blood supply:
Common Carotid Artery
External Carotid Artery Internal Carotid
Ophthalmic
Superficial Facial Artery Maxillary Artery
Temporal Artery
Artery Supraorbital Supratrochlear
Infraorbital Mental Artery Artery Artery
Artery
2) Venous drainage:
Facial Vein Superficial Retromandibular
Temporal Vein
Vein
External and
Internal Jugular
Veins
Nerve Supply of the face
Sensory for the skin
Motor for the muscles

33. Sensory Supply:
Trigeminal Nerve
V
Ophthalmic Maxillary Division Mandibular
division V1 V2 Division V3
From angle of the eye to the Angle of the mouth
Skin of the face from the angle of the mouth. Lower downwards. Parotid
angle of the eye upwards. eyelid, skin of cheeks, upper region, lower lip, chin,
Upper eyelid skin, anterior lip lateral side of the scalp
and lateral parts of the
nose, forehead
Motor Supply:
All muscles of facial expression are supplied by the facial nerve (VII) except the levator palpebrae
superioris muscle which is supplied by the occulomotor nerve (III)
Facial Nerve gives 5 motor branches:
- Temporal
- Zygomatic
- Buccal
- Mandibular
- cervical
Facial Palsy: damage to the facial nerve
It leads to:
paralysis to ½ of the face
inability to whistle
inability to close eyes leading
To dry and ulcerated cornea
inability to blow
angle of mouth droops causing saliva to come out
face will shift towards normal side

34. Parotid Region
It is the area in the side of the face inferior and anterior to the ear
salivary glands in the parotid region are:
o parotid: the largest salivary gland
o submandibular
o sublingual
o scattered small salivary glands in the submucosa of the cheeks
saliva is either
o serous (water like)
o mucous (thicker)
o it helps in digestion, turning food into a bolus thus making swallowing easier and also
helps in speech
1) parotid salivary glands:
- 1 on each side: wedge shaped, exocrine gland
- It has 3 surfaces:
o Anteromedial surface: faces the massetter muscle, medial pterygoid
muscle and ramus of mandible
o Posteromedial surface: faces the mastoid process and
sternocleidomastoid muscle
o Lateral surface: faces the skin and great auricular nerve
- Surrounded by parotid capsule which is a continuation of the investing layer of
the deep fascia
- Stansen’s duct: the opening of the parotid gland. Starts from the anterior border
of the gland and then passes through the massetter and turns medially to pierce
the buccinator muscle then pens into the vestibule opposite to the upper second
molar
- Structures that pass within the
parotid gland:
o Facial nerve
o Retromandibular vein
o External carotid
artery
o Auriculotemporal
nerve
Facial Nerve: enters the parotid gland without
supplying it from the posteromedial surface, dividing
it into a deep lobe and a superficial lobe. It ends
within the parotid gland giving five terminal motor

35. branches (temporal, zygomatic, Buccal mandibular, cervical)
Structures passing into the parotid gland:
1) Veins
- Superficial vein and maxillary vein join into the gland to form the
retromandibular vein.
- The retromandibular vein then divides into anterior and posterior divisions
- The anterior division joins the facial vein to form the common facial vein which
extends as the internal jugular vein
- The posterior division joins the great auricular vein to form the external jugular
Superficial vein Facial Common
temporal Retromandibular Facial
Parotid
gland Ant. division Internal jugular
Maxillary
Posterior External jugular
division Great
auricular
2) Arteries:
- External carotid enters the gland and ends in it by giving superficial temporal
artery and maxillary artery
Nerve Supply of the gland
1) Sensory:
a. by auriculotemporal nerve which is branch of V3
b. carries pain sensation from the capsule of the parotid gland
2) Autonomic:
a. Sympathetic:
i. By sympathetic plexus surrounding external carotid artery
ii. Decreases salivation and secretions (dry mouth)
b. Parasympathetic
i. By glossopharyngeal carried by the lesser petrosal nerve
ii. The salivary nuclei located in the brain is responsible for the production of saliva
iii. The preganglionic parasympathetic, stops to relay in otic ganglia, located in the
infratemporal fossa
iv. Post ganglionic fibers runs to the parotid gland with the auriculotemporal nerve
Lesser Petrosal Auriculotemporal

36. Damage to the
gland can lead to
damage to the
Pre ganglionicfacial nerve
Blood Supply of the gland: Parasympathetic Post ganglionic
Secretomotor Fibers Parasympathetic
Otic Ganglia
- Arterial blood supply: through external carotidartery and terminal
branches of
Secretomotor Fibers
superficial temporal artery and maxillary artery
- Venous drainage: through maxillary vein and superficial temporal vein of the
retromandibular
Lymph nodes:
- Drainage is by the parotid lymph nodes and the deep cervical lymph nodes
Mumps: viral infection of the parotid gland
Parotitis: bacterial infection of the parotid gland

37. The Orbit
2 cavities, pyramidal in shape, located in the anterior view of the skull
Each orbit has:
- Base: directed forwards
- Apex: directed backwards
- 4 orbital margins
- 4 walls
I. Roof: separates the orbital cavity from the anterior cranial fossa. Formed from lesser
wing of sphenoid and orbital plate of frontal bone
II. Floor: separates orbit from maxillary air sinuses. Formed from maxilla and zygoma
III. Lateral wall: separates orbit from temporal fossa, formed from zygomatic bone and
greater wing of the sphenoid
IV. Medial wall: separates orbital and nasal cavities, formed from lacrimal, labyrinth of
ethmoid bone and part of palatine bone
- Openinings in the orbit:
1. Superior orbital fissure: communicates with the middle cranial fossa
2. Optic canal: communicates with the anterior cranial fossa/middle cranial fossa
3. Infra-orbital fissure: communicates with the pterygopalatine fossa
4. Supraorbital notch: communicates with the anterior surface of forehead
5. Infraorbital notch: communicates with the face

38. 6. Nasolacrimal duct: connects the nasal cavity to the orbit
- Contents of the orbit
I. Eyeball
II. Muscles
III. Nerves
IV. Blood vessels
V. Fat
VI. Lacrimal apparatus
VII. Ciliary ganglion
I. Eyeball: spherical in shape, camera of the body, consists of 3 layers
a. Outer layer: a fibrous coat that protects the eye. Formed from sclera and cornea
i. Sclera:
1. provides attachment to the muscles
2. white in color
3. protects the eyeball
ii. cornea:
1. transparent part
b. Middle layer: also called the vascular coat.
i. Choroid: becomes enlarged anteriorly to form the Ciliary body
ii. iris: a forward extension of the Ciliary body which gives the color of the eye
(pigmented coat)
iii. pupil: an opening in the middle
iv. 2 muscles of the eye for visual adaptation (affected by the amount of light)
1. Constrictor pupilae: is stimulated by high light intensity and is under
parasympathetic control
2. Dilator pupilae: is stimulated by absence of light, under sympathetic
control
v. Lens: connected to Ciliary body by suspensory ligaments
vi. Ciliary muscles: group of involuntary muscles in Ciliary body
1. Change thickness of lens by changing length of suspensory ligaments
2. Allows for visual accommodation (ability to see far and near)
c. Inner layer: nervous coat called the retina
i. Has many photsensory receptors (rods and cons)
1. Rods: for dark light
2. Cons: for daylight, colors and moving objects
ii. Optic nerve: originates from the retina from the rods and cons
iii. Fibers travel posteriorly from the rods and cons to form the optic nerve
iv. Fundus: site of attachment of the optic nerve to the eyeball. It has no rod and
cons, thus it’s a blind spot
- Chambers of the eyeball: divided because of presence of lens
d. Anterior chamber: contains aqueous humor (an aqueous watery fluid)
e. Posterior chamber: contains vitreous humor (jelly like fluid) it gives the round shape of
the eyes

39. - Eyelids:
f. Conjunctiva:
i. the lining of the eyelids
ii. a transparent membrane inner surface which turns to line the eyeball
iii. inflammation can occur leading to red itchy eyes (conjunctivitis)
II. Fat:
a. Allows eye to move freely within the bony orbit
b. Supports the eyeball
III. Muscles
There are 2 groups of muscles in the eye
1. Intraocular: muscles inside the eyeball
a. Constrictor
b. Dilator
c. Ciliary muscles
2. Extraocular: muscles inside the orbit (outside the eyeball)
a. Recti (meaning straight)
i. Superior rectus
ii. Inferior rectus Nerve
iii. Medial rectus Supply:
iv. Lateral rectus
b. Oblique LR6 SO4 3

40. i. Superior oblique
ii. Inferior oblique
c. Levator palpebrae superioris
Movements of the Eyes
Right eye Left eye Movement
Superior Rectus3 Superior rectus3
Inferior Rectus3 Inferior Rectus3
Lateral Rectus6 Medial Rectus3
Medial Rectus3 Lateral Rectus6
Inferior Oblique3 Superior Rectus3
Superior Rectus3 Inferior Oblique3
Superior Oblique4 Inferior Rectus3
Inferior Rectus3 Superior Oblique4
Testing the function of the nerves through eye
movements:
- Abducens VI: look lateral by left eye
- Trochlear IV: look down and lateral by
right eye
- Occulomotor III: look at any other
direction
Problems With the eye:
- Convergent Squint/diplopia/strabismus:
double vision created when both eyes move
medially
- Divergent Squint; when one eye moves
normally and the other eye moves laterally
IV. Nerves:
a. Optic nerve II:
i. pure sensory nerve for vision
The remaining
ii. arises from the retina and goes into the brain
cranial nerves arise
iii. Nasal part of retina views pictures coming from lateral/ temporal side
from the brain stem
iv. Lateral part of retina views vision from medial side, these are called visual field

41. v. The two fibers join to form the optic nerve
Decussation:
vi. Nasal fibers of the optic nerves cross the midline forming the optic chiasma, it
crossing of fibers to
contains nasal fibers of both eyes
the opposite side vii. Optic tract: the continuation of the nasal fibers of the opposite side eye and the
temporal fibers of the eye on the same side
viii. The optic tract ends in the visual cortex of the occipital lobe of the brain
If someone
Optic chiasma is
receives a hit in the
closely related to
back of the brain, it
the pituitary gland,
can affect vision
thus any damage to
(visual cortex)
the pituitary gland
affects the chiasma
Damage to the optic nerve: one eye is blind
Damage to chiasma: bitemporal hemianopia (blindness of the fields from the lateral side)
Damage to optic tract: contralateral hemianopia (blindness of the temporal of one eye and nasal of
the other eye)

42. Damage to the occulomotor
causes: 3D
Diplopia
Nerves passing through the optic cavity:
Drooping of upper eyelid= ptosis
1. V1 of the trigeminal
Dilated pupil
a. Pure sensory nerve
b. Enters the orbit through superior orbital fissure
c. Branches:
i. Lacrimal: sensory, supplies lacrimal gland, conjunctive and the skin of the upper eyelid
ii. Frontal: ends by giving 2 terminal branches
1. Supraorbital : supply upper eyelid, scalp, skin of the forehead, and frontal air sinuses
2. Supratrochlear : supply upper eyelid, scalp, skin of the forehead, and frontal air sinuses
iii. Nasociliary:has 2 parts:
a. Visceral secretomotor: receives post ganglionic parasympathetic fibers from ciliay ganglia to
supply the Ciliary body (muscles of the iris=constrictor pupilae) and lacrimal gland
b. Sensory: supplies nasal cavity, skin of the nose, skin of upper eyelid and ethmoidal air cells
2. Occulomotor nerve: arises from the brain stem and enters the orbit through the superior orbital fissure.
Has 2 components:
1. Motor: to all muscles of the orbit except the superior oblique and the lateral rectus
2. Parasympathetic: preganglionic fibers which pass through the ciliary ganglia to supply the
ciliary muscles (constrictor pupilae). It’s also responsible for visual accommodation
a. To test the function of the Trochlear:
ii. Defect in eyeball movement
iii. Drooping
iv. Light reflex
3. Trochlear: arises from the brain stem.
a. Enters orbit through superior orbital fissure
b. Pure motor nerve
c. Supplies only superior oblique
4. Abducens arises from the brain stem.
a. Enters orbit through superior orbital fissure
b. Pure motor nerve
c. Supplies only lateral rectus
5. V2 of the trigeminal: pure sensory
a. Leaves skull through foramen Rotundum, to go to pterygopalatine fossa
b. Enters the orbit and become Infraorbital nerve, which runs in the floor of the orbit and leaves the
orbit through the Infraorbital foramen
c. Supplies
The pterygopalatine
I. the skin of the face form angle of the eye to the angle of the mouth
ganglia is suspended
II. nasal cavity
III. maxillary air sinus by V2, but is
IV. upper teeth functionally related
V. part of the pharynx to the facial nerve
d. Branches:
I. Posterior superior alveolar nerve.
II. Middle superior alveolar nerve

43. III. Anterior superior alveolar nerve
V. Ciliary Ganglia: small pin head sizes parasympathetic ganglia
a. Functionally related to occulomotor nerve
b. Receives preganglionic fibers
c. Postganglionic fibers pass through the nasociliary nerve
VI. Blood Vessels
a. Arteries: ophthalmic artery,
i. a branch of internal carotid artery
ii. enters the orbit through optic canal, and ends by giving terminal branches
1. supraorbital
2. Supratrochlear
iii. Before entering the orbit it gives central retinal artery which runs in the center of
the optic nerve
iv. Damage can result in blindness, as it supplies the retina
b. Vein:
i. Superior ophthalmic vein: formed by union of supra orbital, Supratrochlear and
angular veins
ii. Inferior ophthalmic vein: forms by small veins in the orbit joined together and
drain into the cavernous sinus
iii. Both leave the obit
VII. Lacrimal Apparatus: contains
a. Lacrimal gland
b. Canaliculi
c. Lacrimal sac
d. Nasolacrimal duct
- Lacrimal gland:
I. an exocrine gland,
II. produces and secretes tears
III. located in upper lateral side of the orbit
IV. has 2 parts
 large orbital part
 small palpebral part
V. receives its parasympathetic fibers from facial nerve, carried by greater petrosal nerve
VI. tears flow on the anterior surface of the eyeball
VII. blinking distributes the tears to moisten the eyeball
VIII. All tears will accumulate in the medial angle
IX. Superior and inferior punctums: openings in the medial surface of the eye (corner) which
pass the tears on to the canaliculi
- Canaliculi: small ducts which drain the tears to the lacrimal sac, closely related to the medial wall
of the orbit
- Nasolacrimal duct: connects the lacrimal sac to the wall of the nasal cavity, thus making a pathway
for draining the tears (passes through lacrimal bone)

44. - Tears are then absorbed by the nasal mucosa
- Nasal mucosa inflammation: blocked opening = teary eyes
- Crying: excessive tear production, therefore inability of mucosa to absorb it all, leading to runny
nose
The end