topic 5 bone of skull neck
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Skull, Neck and Muscles
By : Hermizan HalihanafiahBsc Biomedical Sc (Hons), [email protected]
http://www.slideshare.net/hermizan84
SkullContains 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.
Cranial Bones (8 bones)
1 Frontal bone
2 parietal bones
2 temporal bones
1 Occipital bone
1 Sphenoid bone
1 Ethmoid bone
Facial bones (14 bones)
2 nasal bones
2 maxillas
2 zygomatic bones
Mandible
2 lacrimal bones
2 palatines bone
2 inferior nasal
conchae
Vomer
Figure 8.4a
Figure 8.4b
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.
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.
Function of the skull
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.
Frontal BonesFrontal 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.
Frontal Bones
Frontal sinuses lie deep to the frontal
squama.
Sinuses, or called parasinuses, are
mucous membrane – lined cavities in
certain skull bones.
Figure 8.8
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.
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.
Zygomatic archMandibular Fossa
Articular Tubercle
Figure 8.4b
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.
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.
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.
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.
Temporal Bone
Figure 8.4a
Zygomatic arch
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.
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.
Temporal Bone
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.
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.
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.
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.
Occipital Bone
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.
Sphenoid
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.
Sphenoid Bone
Figure 16.11 The sphenoid bone viewed from above.
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.
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.
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.
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.
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.
Sphenoid Bone
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
Ethmoid
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.
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
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.
Ethmoid Bone
Figure 16.12 The right ethmoid bone and its related structures.
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.
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.
Ethmoid Bone
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
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.
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.
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.
Maxillae
Maxillae
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.
Lacrimal Bones
In pairSmallest bones of the faceThin, resemble a fingernail in size and shapePosterior and lateral to nasal bones and form
a part of medial wall of each orbitContain lacrimal fossa, vertical tunnel formed
with maxilla, that houses for the lacrimal sac.Lacrimal fossa – gathers tears and passes
them into the nasal cavity.
Palatine Bones
In pairL-shapedForm 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
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
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
Inferior Nasal Conchae
VomerTriangular 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.
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
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
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
Mandible
The inferior alveolar nerves and blood
vessels, which are distributed to the
mandibular teeth, pass through this canal.
Mandible
Figure 8.15
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.
Consists horizontal body and paired
projection called the lesser horns and the
greater horns.
Muscles and ligaments attach to these
paired projection.
Hyoid Bone
Hyoid Bone
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
Sutures
Immovable jointHolds skull bone
together5 prominent
suture:CoronalSagittalLambdoidSquamousmetopic
Paranasal Sinuses
Cavities within certain cranial and facial bones and connecting with nasal cavity
Lined with mucous membrane.
Frontal, sphenoid, ethmoid and maxillary sinus.
Fontanels
Soft spot – areas of unossified mesenchyme.
Soon after birth it gradually become suture (intramembranous ossification)
Anterior fontanelPosterior fontanelAnterolateralPosterolateral
•The largest – diamond shape
•Closes – 18 – 24 months
•Smaller than anterior
•Closes – 2 months
•Small, irregular shape
•Closes – 3 months•Small, irregular shape
•Closes – 1-2 months
Muscles of Facial Expression
Scalp muscles
Mouth muscles
Neck muscles
Orbit and eyebrow muscles
Scalp Muscles
Frontalis (anteriorly)
Occipitalis
(posteriorly)
Mouth musclesOrbicularis oris
Zygomaticus major
Zygomaticus minor
Levator labii superioris
Depressor labii inferioris
Depressor anguli oris
Levator anguli oris
Buccinator
Risorius
Mentalis
Orbit and Eyebrow Muscles
Oribicularis oculi
Corrugator supercilli
Levator palpebrae superioris
Muscles Of Mastication
Muscles move the mandibleMuscles move the tongue (extrinsic
tongue muscles)
Muscles Move the Mandible
Masseter
Temporalis
Medial pterygoid
Lateral pterygoid
Muscles Move The Tongue
Genioglossus
Styloglossus
Platoglossus
hyoglossus
Muscles of the Anterior Neck
Located superior to the hyoid bone
(suprahyoid muscles)
1. Digastric
2. Stylohyoid
3. Mylohyoid
4. geniohyoid
Located superior to the hyoid bone
(Infrahyoid muscles)
1. Omohyoid
2. Sternohyoid
3. Sternothyroid
4. Thyrohyoid
Muscles of the Anterior Neck
Muscles that Move the Eyeball(Extrinsic Eye Muscles)
Superior rectus
Inferior rectus
Lateral rectus
Superior oblique
Inferior oblique
Levator palpebrae superioris
Muscles that Moves the Head
Sternocleidomastoid
Semispinalis capitis
Splenius capitis
Longissimus capitis
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