anatomy

1. The Head And Neck Anatomy
Osteology & articulations of
the skull and neck
Dr. Emad Abu Alrub MD PhD
AAUP- medicine
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Dr. Emad Abu Alrub MD PhD

2. OVERVIEW
• The head and neck region of the body contains many important
structures
compressed into a relatively small area.
• The skull, with the enclosed brain and meninges, forms most of
the head.
• The special senses (the eye, ear, olfactory area, taste receptors) lie
within the skull bones or in the cavities bounded by them.
• The brain gives rise to 12 pairs of cranial nerves, which leave the
brain and pass through foramina and fissures in the skull.
• All the cranial nerves are distributed to structures in the head and
neck, except the 10th, which also supplies structures in the chest
and abdomen.
• The digestive and respiratory systems begin in the head and
traverse the neck to reach the thorax and abdomen.
• Additionally, key endocrine organs are located in the head and
neck.
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3. • Head injuries from blunt trauma and penetrating missiles are
associated
with high mortality and severe disability.
• Headaches are usually caused by nonserious conditions such as
sinusitis or neuralgia; however, they can represent the earliest
manifestations of a life-threatening disease.
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4. OSTEOLOGY
The skeleton of the head and neck includes:
 The skull,
 Middle ear ossicles,
 Hyoid bone, and
 Cervical vertebrae.
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Dr. Emad Abu Alrub MD PhD

5. The anatomical
position of the skull:
The lower margins of
the orbits and the
upper margins of
the external acoustic
meati are in the same
horizontal plane.
This is termed the
orbitomeatal plane
(“Frankfurt plane”).
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6. The skull
• The bones of the skull are organized into
 A cranial skeleton that surrounds the brain and
 A facial skeleton.
• The cranial cavity is the space containing the brain.
• The skull vault (calvarium) is the upper part of the cranium and
forms the roof and side walls of the cranial cavity.
• The base of the skull is the lowest part of the cranium and forms
the floor of the cranial cavity
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7. The cranium consists of the
following bones, two of
which are paired: 8
 Frontal bone: 1
 Parietal bones: 2
 Occipital bone: 1
 Temporal bones: 2
 Sphenoid bone: 1
 Ethmoid bone: 1
The skull 22
The facial skeleton consists of the
following, two of which are single: 14
 Zygomatic bones: 2
 Maxillae: 2
 Nasal bones: 2
 Lacrimal bones: 2
 Vomer: 1
 Palatine bones: 2
 Inferior conchae: 2
 Mandible: 1
Auditory
ossicles: 6
• Malleus (2)
• Incus (2)
• Stapes (2)
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Hyoid bone: 1

8. Sutures
A suture is an immovable joint that holds
most skull bones together-
four prominent ones:
1. The coronal suture: Unites the
frontal bone and both parietal bones.
2. The sagittal suture: Unites the two
parietal bones on the superior midline
of the skull.
3. The lambdoid suture: Unites the two
parietal bones to the occipital bone.
4. The two squamous sutures: Unite
the parietal and temporal bones on the
lateral aspects of the skull
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9. Anterior view
The norma frontalis is roughly oval in
outline, being wider above than below.
Bones seen
1. Frontal bone forms the forehead. Its
upper part is smooth and convex, but the
lower part is irregular and is interrupted
by the orbits and by the anterior bony
aperture of nose.
2. The right and left maxillae form the
upper jaw.
3. The right and left nasal bones form the
bridge of the nose.
4. The zygomatic bones form the bony
prominence of the superolateral part of
the cheeks.
5. The mandible forms the lower jaw.
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Dr. Emad Abu Alrub MD PhD

10. Orbits
Each orbital opening is quadrangular in shape and
is bounded by the following four margins:
1. The supraorbital margin is formed by the
frontal bone. At the junction of its lateral two-
thirds and its medial one-third, it presents the
supraorbital notch or foramen.
2. The infraorbital margin is formed by the
zygomatic bone laterally, and maxilla medially.
3. The medial orbital margin is ill-defined. It is
formed by the frontal bone above, and by the
lacrimal crest of the frontal process of the
maxilla below.
4. The lateral orbital margin is formed mostly
by the frontal process of zygomatic bone, but
is completed above by the zygomatic process
of frontal bone. Frontozygomatic suture lies at
their union.
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13. Lateral view
Bones seen
1. Frontal
2. Parietal
3. Occipital
4. Temporal
5. Sphenoid
6. Zygomatic
7. Mandible
8. Maxilla
9. Nasal
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14. Features/ lateral view
• Temporal Lines
• Zygomatic Arch or Zygoma
• External Acoustic Meatus
• Styloid Process
• Temporal Fossa
• Mastoid Part of the
Temporal Bone
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15. Clinical Connection
Pterion site of anterolateral fontanelle is the thin part of skull.
In roadside accidents, the anterior division of middle
meningeal artery at pterion may be ruptured, leading to clot
formation between the skull bone and dura mater or
extradural Haemorrhage.
The clot compresses the motor area of brain, leading to
paralysis of the opposite side.
The clot must be sucked out at the earliest by trephining.
The head must be protected by a helmet during driving a two-
wheeler.
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17. Superior view
Shape
When viewed from above, the
skull is usually oval in shape.
It is wider posteriorly than
anteriorly.
The shape may be more nearly
circular.
Bones
1. Upper part of frontal bone—
anteriorly.
2. Uppermost part of occipital
bone—posteriorly.
3. A parietal bone—on each
side.
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Dr. Emad Abu Alrub MD PhD

18. Superior view
Sutures seen:
1 Coronal suture: This is placed between the
frontal and the two parietal bones. The suture
crosses the cranial vault from side-to-side and runs
downwards and forwards.
2 Sagittal suture: It is placed in the median plane
between the two parietal bones.
3 Lambdoid suture: It lies posteriorly between the
occipital and the two parietal bones, and it runs
downwards and forwards across the cranial vault.
4 Metopic (Latin forehead) suture: This is
occasionally present in about 3 to 8% individuals.
It lies in the median plane and separates the two
halves of the frontal bone. Normally, it fuses at 6
years of age.
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19. Posterior view- skull
Norma occipitalis is convex
upwards and on each side,
and is flattened below.
Bones seen:
1 Posterior parts of the
parietal bones—above.
2 Upper part of the
squamous part of the
occipital
bone—below.
3 Mastoid part of the
temporal bone—on each
side.
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20. NORMA OCCIPITALIS/ posterior view-
skull
Sutures seen:
1. The lambdoid suture lies between the
occipital bone and the two parietal bones.
Sutural or wormian bones are common along
this suture.
2. The occipitomastoid suture lies between the
occipital bone and mastoid part of the
temporal bone.
3. The parietomastoid suture lies between the
parietal bone and mastoid part of the
temporal bone.
4. The posterior part of the sagittal suture is
also seen.
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21. Other Features seen:
1. Lambda.
2. The external
occipital
protuberance -
inion.
3. The superior nuchal
lines
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Dr. Emad Abu Alrub MD PhD

22. NORMA BASALIS/ Inferior view of
the skull
The norma basalis is divided arbitrarily
into anterior, middle and posterior
parts.
• The anterior part is formed by the
hard palate and the
alveolar arches.
• The middle and posterior parts are
separated by an imaginary
transverse line passing through the
anterior margin of the foramen
magnum
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24. Floor
The floor of the cranial cavity is divided into anterior, middle, and posterior
cranial fossae.
Anterior cranial fossa
Parts of the frontal, ethmoid, and sphenoid bones form the anterior cranial
fossa. Its floor is composed of:
■ frontal bone in the anterior and lateral direction,
■ ethmoid bone in the midline, and two parts of the sphenoid bone
posteriorly, the body (midline) and the lesser wings (laterally).
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25. Middle cranial fossa
The middle cranial fossa consists of parts of the sphenoid and temporal bones. The
boundary between the anterior and middle cranial fossae in the midline is the
anterior edge of the prechiasmatic sulcus, which is a smooth groove stretching
between the optic canals across the body of the sphenoid.
The posterior boundaries of the middle cranial fossa are formed by the anterior
surface, as high as the superior border, of the petrous part of the petromastoid part
of the temporal bone.
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Dr. Emad Abu Alrub MD PhD

26. Posterior cranial fossa
The posterior cranial fossa consists mostly of parts of the temporal and occipital
bones, with small contributions from the sphenoid and parietal bones. It is the
largest and deepest of the three cranial fossae and contains the brainstem
(midbrain, pons, and medulla) and the cerebellum.
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29. Craniometric points
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32. Anterior fontanel
closes 18 to 24
months after birth.
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33. Baby skull superior view
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35. Cervical Vertebrae
Cervical vertebrae (C1–C7) are smaller than
all other vertebrae except the coccyx.
The first two cervical vertebrae are special.
 The atlas (C1), is the first cervical vertebra
inferior to the skull it is a ring of bone with
anterior and posterior arches and large
lateral masses.
It lacks a body and a spinous process.
 The second cervical vertebra (C2), the
axis does have a vertebral body.
A peglike process called the dens or
odontoid process projects superiorly through
the anterior portion of the vertebral foramen of
the atlas.
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40. Cervical Intervertebral Disc
There are 6 intervertebral discs
in the cervical spine.
Each cervical disc is situated
between adjacent vertebrae
(one above and one below) to
cushion the vertebral bodies and
help distribute loads from the
neck and head above.
A disc has 2 basic components:
 Annulus fibrosus.
 Nucleus pulposus
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43. Temporomandibular Joint
(TMJ)
 Is a combined hinge and
plane joint formed by the
condylar process of the
mandible and the
mandibular fossa and
articular tubercle of the
temporal bone.
 Only movable joint between
skull bones
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44. Anatomical Components
1. Articular disc (meniscus). Fibrocartilage disc that
separates
the synovial cavity into superior and inferior
compartments,
each with a synovial membrane
2. Articular capsule. Thin, fairly loose envelope around
the circumference
of the joint .
3. Lateral ligament. Two short bands on the lateral
surface of
the articular capsule. The lateral ligament is covered by
the parotid gland .
4. Sphenomandibular ligament
5. Stylomandibular ligament
Movements: elevation & depression
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Thank you!