U wanna know about the structure of the skull??? here we go...

1. Skull, Neck and
Muscles
By : Hermizan Halihanafiah
Bsc Biomedical Sc (Hons), UKM
hermizanhalihanafiah@yahoo.com
http://www.slideshare.net/hermizan84

2. Skull
 Contains 22 bones
 Rest superior to the
vertebral column
 Consists 2 sets of bones,
facial and cranial bones
 Cranial bones forms the
cranial cavity, which
encloses and protect the
brain
 Facial bones form the face.

3. Cranial Bones (8 bones)
 1 Frontal bone
 2 parietal bones
 2 temporal bones
 1 Occipital bone
 1 Sphenoid bone
 1 Ethmoid bone

4. Facial bones (14 bones)
 2 nasal bones
 2 maxillas
 2 zygomatic bones
 Mandible
 2 lacrimal bones
 2 palatines bone
 2 inferior nasal
conchae
 Vomer

5. Figure 8.4a

6. Figure 8.4b

8. Function of the skull
 Protect the brain
 Inner surface attach to the membranes (meninges)
that stabilize the position of the brain, blood
vessels and nerves.
 Outer surface of cranial bones provide large areas
for muscle attachment that move various part of
the head.
 The bones also provide muscle attachment for
some muscles that produce facial expressions.

9. Function of the skull
 Facial bones – forms framework of the face
 Facial bones – provide support for entrance to the
digestive and respiratory system
 Together cranial and facial bones protect and
support the delicate special sense organs for vision,
taste, smell, hearing and equibilirium.

11. Frontal Bones
 Forms the forehead, the roof of the orbits
and most of the anterior part of the cranial
floor
 Soon after birth, the left and right side of
the frontal bone united together by the
metopic suture, usually disappear by age
of six to eight.

14. Frontal Bones
 Frontal Bone that forms the forehead – Frontal
squama
 Superior to the orbits the frontal bone thickens,
forming the supraorbital margin.
 From this margin, the frontal bone extends
posteriorly to form the roof of the orbits, which is part
of the floor of the cranial cavity.
 Within the supraorbital margin, slightly medial to its
midpoint, is a hole called supraorbital foramen where
supraorbital nerve and artery pass through it.

15. Frontal Bones
 Frontal sinuses lie deep to the frontal
squama.
 Sinuses, or called parasinuses, are
mucous membrane – lined cavities in
certain skull bones.

16. Figure 8.8

17. Parietal Bones
 2 parietal bones
 Form the greater portion of the side and
roof of the cranial cavity
 Internal surface of parietal bones contain
many protrusion and depression that
accommodate the blood vessels supplying
the dura mater (superficial connective
tissue that lining the brain.
 No foramina in the parietal bones.

19. Temporal Bones
 2 temporal bones
 Form the inferior lateral aspects of the
cranium and part of the cranial floor
 Lateral view of the temporal bones, called
temporal squama, the thin, flat part that form
the anterior and superior part of the temple.
 Projecting from the inferior portion of the
temporal squama is the zygomatic process.

20. Mandibular Articular
Fossa Zygomatic arch
Tubercle

21. Figure 8.4b

22. Temporal Bone
 Zygomatic process of temporal bones
articulate with temporal process of zygomatic
(cheek) bone form the zygomatic arch
 A socket called the mandibular fossa is
located on the inferior posterior surface of the
zygomatic process of the temporal bones.
 Anterior to the mandibular fossa is a rounded
elevation called articular tubercle.

24. Temporal Bone
 The mandibular fossa and articular tubercle
articulate with the mandible (lower jawbone)
to form the temporomandibular joint (TMJ).
 Located posteriorly on the temporal bone is
the mastoid portion.
 It is located posterior and inferior to the
external auditory meatus or ear canal.

25. Temporal Bone
 The mastoid process is a rounded projection
of the mastoid portion of the temporal bone
posterior to the external auditory meatus.
 It is the point for several neck muscles
attachment.
 The internal auditory meatus is the opening
through which facial nerve (cranial nerve VII)
and vestibulocochlear nerve (cranial nerve
VIII) passes.

26. Temporal Bone
 The styloid process projects inferiorly from
the inferior surface of the temporal bones
and serve as a point of attachment for
muscles and ligaments of the tongue a neck.
 Between the styloid process and mastoid
process is the stylomastoid foramen.

27. Figure 8.4a
Zygomatic arch

28. Temporal Bone
 At the floor of the cranial cavity is the
petrous portion of the temporal bone.
 This part is the triangular and it is located
at the base of the skull between the
sphenoid and occipital bones.
 The petrous portion houses the internal
and middle ear, structure involve hearing
and equibilirium.

29. Temporal Bone
 It also contain the carotid foramen,
through which the carotid artery passes.
 Posterior to the carotid foramen and
anterior to the occipital bone is the jugular
foramen, passageway for the jugular vein.

30. Occipital Bone
 Forms the posterior part and most of the
base of the cranium
 The foramen magnum is in the inferior part
of the bone.
 Within this foramen, the medulla
oblongata connect with the spinal cord.
 The vertebral and spinal arteries also pass
through this foramen.

32. Occipital Bone
 The occipital condyles are oval processes with
convex surface, one on either side of the
foramen magnum.
 They articulates with depression on the 1st
cervical vertebra (atlas) to form the atlanto-
occipital joint.
 Superior to each occipital condyle on the
inferior surface of the skull is the hypoglossal
foramen.

34. Occipital Bone
 The external occipital protuberance is a
prominent midline projection on the
posterior surface of the bone just above the
foramen magnum.
 A large fibrous, elastic ligament, the
ligamentum nuchae, which help support the
head, extend from the external occipital
protuberance to the 7th cervical vertebra.

36. Occipital Bone
 Extending laterally from the protuberance
are two curved ridges, the superior nuchal
lines, and below these are two inferior
nuchal lines, which is areas for the
muscles attachment.

37. Sphenoid Bone
 Lies at the middle part of the base of the skull.
 Keystone of the cranial floor because it
articulates with all the other cranial bones,
holding them together
 Sphenoid articulation – joins anteriorly with
the frontal bone, laterally with the temporal
bones and posteriorly with the occipital
bones.

38. Sphenoid

39. Sphenoid Bone
 Lie posterior and slightly superior to the
nasal cavity and forms part of the floor, side
walls, and rear wall of the orbit.
 The shape of the sphenoid resembles a bat
with outstretched wings.
 The body of the sphenoid is the cube-like
medial portion between the ethmoid and
occipital bones.

40. Figure 16.11 The sphenoid bone viewed from above.

42. Sphenoid Bone
 It contains the sphenoidal sinuses, which
drain into the nasal cavity.
 The sella turcica, ia bony saddle-shaped
structure on the superior surface of the body
of the sphenoid.
 Anterior part of the sella turcica, which form
the horn of the saddle, is a ridge called the
tuberculum sellae.

43. Sphenoid Bone
 The seat of the saddle is a depression,
called hypophyseal fossa, which contain
pituitary gland.
 The posterior part of the sella turcica, which
forms the back of the saddle, is another ridge
called the dorsum sellae.
 The greater wings of the sphenoid project
laterally from the body and form the
anterolateral floor of the cranium.

45. Sphenoid Bone
 The greater wings also form part of the lateral
wall of the skull just anterior to the temporal
bone.
 The lesser wings, which are smaller, form a
ridge of bone anterior and superior to the
greater wings.
 They form part of the floor of the cranium and
the posterior part of the orbit of the eye.

46. Sphenoid Bone
 Between the body and lesser wing, just anterior to the
sella turcica is the optic foramen.
 Lateral to the body between the greater and lesser
wings is a triangular slit called the superior orbital
fissure.
 Pterygoid process – structures project inferiorly from
the point where the body and wings unite and form the
lateral posterior region of the nasal cavity.
 Some of the muscles that move the mandible attach to
the pterygoid process.

47. Sphenoid Bone
 At the base of the pterygoid process in the
greater wings is the foramen ovale.
 The foramen lacerum is bounded
anteriorly by the sphenoid bone and
medially by sphenoid and occipital bones
 Foramen rotundum – located at the
junction of the anterior and medial parts of
the sphenoid bone.

49. Ethmoid Bone
 Light, spongylike bone, located on the
midline in the anterior part of the cranial
floor medial to the orbits.
 Anterior to the sphenoid and posterior to
the nasal bones

50. Ethmoid

51. Ethmoid Bone
 Ethmoid bone forms:
Part of the anterior portion of the cranial
floor
Medial wall of the orbit
Superior portion of the nasal septum
Most of the superior sidewalls of the
nasal cavity.

52. Ethmoid Bone
 The lateral masses of the ethmoid bone
compose most of the wall between the
nasal cavity and orbits.
 Contain 3 to 18 air spaces, or “cells”.
 The ethmoidal cells together to form
ethmoidal sinuses.
 The perpendicular plate forms the superior
portion of the nasal septum

55. Ethmoid Bone
 The cribriform plate lies in the anterior floor of
the cranium and forms the roof of the nasal
cavity.
 The cribriform plate contain olfactory foramina
through which axons of the olfactory nerve
pass.
 Projecting upward from the cribriform plate is
a triangular process called the crista galli.
 This structure is serve as a point of
attachment for the membrane that cover the
brain.

57. Figure 16.12 The right ethmoid bone and its related structures.

58. Ethmoid Bone
 The lateral masses of the ethmoid bone
contain 2 thin, scroll shaped projection
lateral to the nasal septum.
 These are the superior nasal conchae and
middle nasal conchae.
 A third pair of conchae, the inferior nasal
conchae, are separated bones.

60. Ethmoid Bone
 The conchae cause turbulance in inhaled air, which
result in many inhaled particles striking and becoming
trapped in the mucus that lines the nasal
passageways.
 This turbulence thus cleanses the inhaled air before it
passes into the rest of the respiratory tract.
 Turbulence airflow around the superior nasal
conchae also aids in the distribution of olfactory
stimulants for the sensation of smell.
 Air striking and mucous lining of the conhae is also
warmed and moisted.

63. Nasal Bones
 Paired of the nasal bones meet at the
midline
 Form part of the bridge of the nose
 The rest of the supporting tissue of the
nose consists of cartilage

64. Maxillae
 A paired maxillae unite together to form
the upper jawbone
 Articulate with every bone of the face
except the mandible (lower jawbone)
 Forms part of the floor of the orbits, part of
the lateral walls and floor of the nasal
cavity, and most of the hard palate.

65. Maxillae
 The hard palate is a bony partition formed by
palatine process of the maxillae and horizontal
plates of the palatine bones that forms roof of
the mouth.
 Each maxillae contains a large maxillary sinus
that empties into the nasal cavity.
 The alveolar process of the maxillae is an
arch that contain the alveoli (sockets) for the
maxillary (upper) teeth.

66. Maxillae
 The palatine process is a horizontal projection
of the maxillae that forms the anterior three
quarters of the hard palate.
 The union and diffusion of the maxillary bones
normally is completed before birth.
 The infraorbital foramen is an opening in the
maxillae below the orbit.
 Inferior orbital fissure, located between the
greater wing of the sphenoid and the maxilla.

67. Maxillae

68. Zygomatic Bones
 2 zygomatic bones
 Called cheekbones
 Form the prominence of the cheek and
part of the lateral wall and floor of each
orbit
 Articulate with the maxillae and the frontal,
sphenoid and temporal bones.

69. Lacrimal Bones
 In pair
 Smallest bones of the face
 Thin, resemble a fingernail in size and shape
 Posterior and lateral to nasal bones and form
a part of medial wall of each orbit
 Contain lacrimal fossa, vertical tunnel formed
with maxilla, that houses for the lacrimal sac.
 Lacrimal fossa – gathers tears and passes
them into the nasal cavity.

70. Palatine Bones
 In pair
 L-shaped
 Form the posterior portion of the hard palate,
part of the floor and lateral wall of the nasal
cavity, and smallest portion of the floors of the
orbits.
 The horizontal palate of the palatine bones form
the posterior portion of the hard palate, which
separate the nasal cavity and oral cavity

72. Inferior Nasal Conchae
 In pair
 Inferior to the middle nasal conchae of the
ethmoid bone
 Scroll like bones that form a part of the inferior
lateral wall of the nasal cavity and project into
the nasal cavity.
 The inferior nasal conchae is a separate bones,
they are not part of the ethmoid bone

73. Inferior Nasal Conchae
 All three pairs of the nasal conchae help
swirl and filter air before it passes into the
lungs.
 Only superior nasal conchae involve in the
sense of smell

74. Vomer
 Triangular bone
 Located in the floor of the nasal
cavity
 Articulates superiorly with
perpendicular plate of the
ethmoid bone and inferiorly with
both the maxilla and palatine
along the midline
 It is apart of the nasal septum,
partition that divides the nasal
cavity into right and left sides.

75. Mandible
 Lower jawbone
 Largest, strongest facial bone
 Movable skull bone
 Consist of a curved , horizontal portion, the
body, and two perpendicular portions, the rami.
 The angle of the mandible is the area where
each ramus meets the body

76. Mandible
 Each ramus has a posterior condylar process.
 On each condylar process has a articulating surface
called mandibular condyle that articulates with the
mandibular fossa and articular tubercle of the
temporal bones.
 This articulation called temporomandibular joint
(TMJ)
 Has anterior coronoid process to which temporalis
muscles attaches.
 The depression between coronoid and condylar
process called the mandibular notch

77. Mandible
 The alveolar process is an arch containing the alveoli
(sockets) for the mandibular (lower) teeth.
 The mental foramen is located below the mandibular second
premolar tooth.
 The mandibular foramen on the medial surface of each
ramus.
 The mandibular foramen, beginning of the mandibular canal,
which run obliquely in the ramus and anteriorly to the body
deep to the roots of the teeth

78. Mandible
 The inferior alveolar nerves and blood
vessels, which are distributed to the
mandibular teeth, pass through this canal.

79. Figure 8.15

80. Hyoid Bone
 Single
 Unique, does not articulate with any bones
 Suspended from the styloid processes of the
temporal bones by ligaments and muscles.
 Located in the anterior neck between the mandible
and larynx
 Support the tongue, providing attachment sites for
some tongue muscles and for muscles of the neck
and pharynx.

81. Hyoid Bone
 Consists horizontal body and paired
projection called the lesser horns and the
greater horns.
 Muscles and ligaments attach to these
paired projection.

83. Hyoid Bone

84. The Important of Hyoid Bone
 It helps to support the tongue and serves as an attachment
point for several muscles that help to elevate the larynx during
swallowing and speech.
 The hyoid bone is unique in that it is the only bone of the body
that does not articulate with any other bone.
 Instead, it is suspended above the larynx where it is anchored
by ligaments to the styloid processes of the temporal bones of
the skull.
 When depressed it also assists in locating vocal chords when
intubating a patient

85. Sutures
 Immovable joint
 Holds skull bone
together
 5 prominent
suture:
Coronal
Sagittal
Lambdoid
Squamous
metopic

86. Paranasal Sinuses
 Cavities within
certain cranial and
facial bones and
connecting with
nasal cavity
 Lined with mucous
membrane.
 Frontal, sphenoid,
ethmoid and
maxillary sinus.

87. Fontanels
 Soft spot – areas of unossified
mesenchyme.
 Soon after birth it gradually become suture
(intramembranous ossification)
 Anterior fontanel
 Posterior fontanel
 Anterolateral
 Posterolateral

88. •The largest – diamond •Smaller than anterior
shape
•Closes – 2 months
•Closes – 18 – 24 months
•Small, irregular shape
•Small, irregular shape
•Closes – 3 months
•Closes – 1-2 months

89. Muscles of Facial Expression
 Scalp muscles
 Mouth muscles
 Neck muscles
 Orbit and eyebrow muscles

90. Scalp Muscles
 Frontalis (anteriorly)
 Occipitalis (posteriorly)

92. Mouth muscles
 Orbicularis oris
 Zygomaticus major
 Zygomaticus minor
 Levator labii superioris
 Depressor labii inferioris
 Depressor anguli oris
 Levator anguli oris
 Buccinator
 Risorius
 Mentalis

94. Orbit and Eyebrow Muscles
 Oribicularis oculi
 Corrugator supercilli
 Levator palpebrae superioris

99. Muscles Of Mastication
 Muscles move the mandible
 Muscles move the tongue (extrinsic
tongue muscles)

100. Muscles Move the Mandible
 Masseter
 Temporalis
 Medial pterygoid
 Lateral pterygoid

103. Muscles Move The Tongue
 Genioglossus
 Styloglossus
 Platoglossus
 hyoglossus

106. Muscles of the Anterior Neck
 Located superior to the hyoid bone
(suprahyoid muscles)
1. Digastric
2. Stylohyoid
3. Mylohyoid
4. geniohyoid

107. Muscles of the Anterior Neck
 Located superior to the hyoid bone
(Infrahyoid muscles)
1. Omohyoid
2. Sternohyoid
3. Sternothyroid
4. Thyrohyoid

109. Muscles that Move the Eyeball
(Extrinsic Eye Muscles)
 Superior rectus
 Inferior rectus
 Lateral rectus
 Superior oblique
 Inferior oblique
 Levator palpebrae superioris

111. Muscles that Moves the Head
 Sternocleidomastoid
 Semispinalis capitis
 Splenius capitis
 Longissimus capitis

114. THANK YOU!!