axial skeleton: the skull slides by vince austin; figures from marieb & hoehn 8 th ed.;...

Axial Skeleton:The Skull

Slides by Vince Austin;

figures from Marieb & Hoehn 8th ed.;

modifications and some slides by W. Rose

Portions copyright Pearson Education

The Axial SkeletonEighty bones segregated into three regions

– Skull– Vertebral column– Bony thorax

Copyright © 2010 Pearson Education, Inc.

Figure 7.1 The human skeleton.

Skull

Thoracic cage(ribs andsternum)

(a) Anterior view

(b) Posterior view

Facial bonesCranium

Sacrum

Vertebralcolumn

Clavicle

Bones ofpectoralgirdle

Bones ofpelvic girdle

Upperlimb

ScapulaSternumRibHumerusVertebraRadiusUlnaCarpals

PhalangesMetacarpalsFemurPatella Lower

limbTibiaFibula

TarsalsMetatarsalsPhalanges

The SkullSkull Body’s most complex bony structureFormed by the cranium and facial bones Cranium – protects brain; site of attachment for head

and neck musclesFacial bones

– Framework for the face, sense organs, and teeth– Provide openings for passage of air and food– Anchor facial muscles of expression


Figure 7.2a The skull: Cranial and facial divisions and fossae.Bones of cranium (cranial vault)

Lambdoidsuture

Facialbones

Squamoussuture

(a) Cranial and facial divisions of the skull

Coronalsuture

Anatomy of the CraniumEight cranial bones – two parietal, two

temporal, frontal, occipital, sphenoid, and ethmoid

Cranial bones thin and strong for their weight


Figure 7.2b The skull: Cranial and facial divisons and fossae.

Anterior cranialfossa

Middle cranialfossa

Posterior cranialfossa

(b) Superior view of the cranial fossae


Figure 7.2c The skull: Cranial and facial divisions and fossae.

Frontal lobeof cerebrum

Temporal lobeof cerebrumCerebellum

PosteriorMiddleAnterior

Cranialfossae

(c) Lateral view of cranial fossae showing thecontained brain regions


Figure 7.3 Major cavities of the skull, frontal section.

Frontalsinus

Ethmoidsinuses

Orbit Orbit

Cranial cavity

Oralcavity

Maxillarysinus

Inferiornasalconcha

Maxilla

Mandible

Ethmoidbone

Frontalbone

Zygomaticbone

Vomer

Nasalcavity

Frontal BoneAnterior portion of the craniumArticulates posteriorly with the

parietal bones via the coronal suture

Major markings include: supraorbital margins, anterior cranial fossa, frontal sinuses (internal and lateral to the glabella)

Frontal Bone

Figure 7.2a

Parietal Bones and associated suturesForm most of the superior and lateral aspects of the skullCoronal, sagittal, lambdoid, squamous sutures

Figure 7.3a

Lambdoidsuture

Occipital bone

Occipitalcondyle

Mastoidprocess

Parietal bone

Sagittal suture

Sutural (Wormian) bone

Occipital Bone

Forms most of skull’s posterior wall and base

Copyright © 2010 Pearson Education, Inc.Copyright © 2010 Pearson Education, Inc.

Cranial cavity floor

Middle cranialfossa

Posteriorcranial fossa

Occipital bone

Foramen magnum (spinal cord)

Jugular foramen

Anterior cranial fossa

View

Temporal Bones

Form the inferolateral aspects of the skull and parts of the cranial floor

Divided into four major regions – squamous, tympanic, mastoid, and petrous

Major markings include: zygomatic, styloid, and mastoid processes, middle cranial fossa

Major openings include: external auditory meatus, internal auditory meatus, stylomastoid and jugular foramina, carotid canal


Figure 7.8 Right temporal bone, lateral view

Mastoidregion

Externalacousticmeatus

Mastoidprocess

Styloid process

Tympanic region

Zygomatic process

Squamousregion

Sphenoid BoneButterfly-shaped bone that spans the width of

the middle cranial fossaForms the central wedge that articulates with all

other cranial bonesCentral body, greater wings, lesser wings, and

pterygoid processesMajor markings: sella turcica, hypophyseal

fossa, pterygoid processes, sphenoid sinuses, middle cranial fossa

Major openings include: optic canals, superior orbital fissure


Figure 7.7a Cranial cavity floor

Hypophyseal fossaof sella turcica

Middle cranialfossa

Superior view of cranial interior

Frontal bone

Optic canal (cn 2)

Sphenoid Lesser wingGreater wing

View


Figure 7.9 Sphenoid bone

Greaterwing

Hypophysealfossa ofsella turcica

Body of sphenoid

Superiororbital fissure (cn 3, 4, part5, 6)

Superior view

Body of sphenoid

Greaterwing

Superior orbitalfissure (cn 3,4, part5, 6)

Lesserwing

Pterygoidprocess

Posterior view

Optic canal (cn2)

Lesser wing

Ethmoid BoneDeepest skull bone; lies between the sphenoid

and nasal bonesForms most of the bony area between the nasal

cavity and the orbitsMajor markings include: cribriform plate, crista

galli, perpendicular plate, superior & middle nasal conchae, ethmoid sinuses


Figure 7.10 Ethmoid bone

Orbitalplate

Ethmoidalair cells

Perpendicularplate Middle nasal concha

Cribriformplate

Olfactoryforamina

Crista galli

Left lateral mass



Frontal bone

Olfactory foramina

Cribriform plateEthmoidbone Crista galli


View

Facial BonesFourteen bonesOnly mandible and vomer are unpairedPaired bones: maxillae, zygomatics, nasals,

lacrimals, palatines, inferior conchae

MandibleLower jawbone; largest, strongest bone of faceMajor markings include: coronoid process, mandibular condyle,

alveolar margin, mandibular angle, mandibular and mental foramina

Maxillary BonesMedially fused bones make up upper jaw and central portion of

the facial skeletonFacial keystone bones that articulate with all other facial bones

except mandibleMajor markings include: palatine, frontal, and zygomatic

processes (artic. w/ respective bones), alveolar margins, maxillary sinuses


Figure 7.11 Mandible and maxilla

CoronoidprocessMandibular foramen

Mental foramenRamus ofmandible

Mandibularcondyle

Body of mandible

Alveolar margin

Mandibleright lateral view

Temporomandibularjoint

Articulates withfrontal bone

Alveolarmargin

Maxilla, right lateral view

Orbitalsurface

Zygomaticprocess(cut)

Mandibular angle

Facial Bones

Zygomatic Bones - irregularly shaped bones (cheekbones), form prominences of cheeks and inferolateral margins of orbitsNasal bones – thin medially fused bones, form bridge of noseLacrimal bones – contribute to medial walls of orbits; contain lacrimal fossae which house lacrimal sacsPalatine bones – two bone plates, form portions of hard palate, posterolateral walls of nasal cavity, and small parts of orbitsVomer – plow-shaped bone, forms part of nasal septumInferior nasal conchae – paired, curved bones in nasal cavity, form part of lateral walls of nasal cavity


Figure 7.4a Anterior aspect of skull

Parietal bone

Nasal boneSphenoid bone

Temporal boneEthmoid boneLacrimal boneZygomatic bone

MaxillaMandible

Mentalforamen

Frontal bone

Supraorbital marginSuperior orbitalfissure

Inferior orbitalfissure

Inferior nasal conchaVomer

Optic canal

Ethmoidbone


Figure 7.5a Lateral aspect of skull, external view

Coronal suture Frontal bone

Sphenoid bone(greater wing)

Ethmoid bone

Lacrimal bone

Nasal bone

Zygomaticbone Maxilla

Alveolarmargins

MandibleMental foramen

Parietal bone

Lambdoidsuture

SquamoussutureOccipitalbone

External acousticmeatusMastoid processStyloid process

Mandibular condyle

Mandibular ramus

(a) External anatomy of the right side of the skull

Mandibular angle Coronoid process

Zygomaticprocess

Temporal bone


Figure 7.5b Lateral aspect of skull, internal view

Parietal bone

Coronal sutureFrontal bone

Frontal sinus

Crista galliNasal boneSphenoid sinusEthmoid bone(perpendicular plate)Vomer

Maxilla

Mandible

Alveolar margins

LambdoidsutureOccipitalbone

Sella turcicaof sphenoidbone

Pterygoidprocess ofsphenoid boneMandibularforamenPalatine bone

SquamoussutureTemporalbone

Midsagittal section showing the internal anatomy of left half of skull

Sphenoid bone


Figure 7.6a Inferior aspect of skull, mandible removed

Maxilla


External acoustic meatus

Foramen magnum

Occipital condyle

Maxilla

Hardpalate

Zygomatic bone

Temporal bone(zygomatic process)

Vomer

Styloid process

Mastoid process

Temporal bone(petrous part)

Parietal bone

Palatine bone

Orbits

Bony cavities in which the eyes are firmly encased and cushioned by fatty tissue

Formed by parts of seven bones – frontal, sphenoid, zygomatic, maxilla, palatine, lacrimal, and ethmoid


Orbits(cn 3,4,part5,6)

(cn 2)

maxilla

frontal

temporal

Nasal Cavity

Constructed of bone and hyaline cartilageRoof – formed by cribiform plate of ethmoidLateral walls – formed by superior and middle

conchae of ethmoid, perpendicular plate of palatine, and inferior nasal conchae

Floor – formed by palatine process of the maxillae and by palatine


Nasal cavity: left lateral wall Nasal septum removed.

Maxillary bone(palatine process)

Palatine bone Palatine bone

Pterygoidprocess

SphenoidsinusSphenoid

bone

Frontal sinus

Superiornasal conchaMiddlenasal concha

Ethmoidbone

Inferior nasalconcha

Nasal bone

Superior, middle, andinferior meatus


Vomer

Crista galliCribriformplate

Ethmoidbone

Frontalsinus

Nasal bone

Septal cartilage

Alveolar marginof maxilla

Perpendicularplate of ethmoid bone

Sella turcica

Sphenoid sinus

Palatinebone Palatine processof maxilla

Nasal cavity: Midline structures. Septum in place; note contributions of ethmoid bone, vomer, septal cartilage

Hardpalate

Paranasal Sinuses

Mucosa-lined, air-filled sacs found in five skull bones: frontal, sphenoid, ethmoid, and paired maxillary bones

Named for bones in which they resideAir enters paranasal sinuses from nasal cavityMucus drains into nasal cavity from paranasal

sinusesLighten skull; enhance resonance of the voice


Figure 7.15 Paranasal sinuses.

Frontalsinus

Ethmoidalair cells(sinus)

Maxillarysinus

Sphenoidsinus

Frontalsinus

Ethmoidalair cells

Maxillarysinus

Sphenoidsinus

(a) Anterior aspect (b) Medial aspect

Hyoid BoneNot actually part of the skullLies just inferior to mandible in anterior neckOnly bone that does not articulate with another

boneAttachment point for neck muscles that raise and

lower larynx during swallowing and speech


Anterior aspects of skull

Parietal bone

Nasal boneSphenoid bone

Temporal boneEthmoid boneLacrimal boneZygomatic bone

MaxillaMandible

Mentalforamen

Frontal bone

Supraorbital marginSuperior orbitalfissure

Inferior orbitalfissure

Inferior nasal conchaVomer

Optic canal

Ethmoidbone


Coronal suture Frontal bone


Ethmoid bone

Lacrimal bone

Lacrimal fossa

Nasal bone

Zygomaticbone Maxilla

Alveolarmargins

MandibleMental foramen

Parietal bone

Lambdoidsuture

SquamoussutureOccipitalbone

Mandibular ramus

Right side of skull

Mandibular angle Coronoid process

Zygomaticprocess

Temporal bone


Parietal bone

Frontal bone

Frontal sinus

Crista galliNasal boneSphenoid sinusEthmoid bone

Vomer

Maxilla

Mandible

Alveolar margins

LambdoidsutureOccipitalbone

Sella turcicaof sphenoidbone Mandibular

foramenPalatine bone

Temporalbone

Internal anatomy of left half of skull (midsagittal section)

Maxilla

Sphenoid bone



Hypophyseal fossaof sella turcica

Middle cranialfossa

Temporal bone

Posteriorcranial fossa

Parietal bone

Occipital bone

Foramen magnum

Frontal bone

Olfactory foramina

Optic canal

Hypoglossal canal

Cribriform plateEthmoidbone Crista galli

Sphenoid


Lesser wingGreater wing

View


Maxilla


Carotid canal

Foramen magnum

Occipital condyle

Maxilla

Hardpalate

Zygomatic bone

Temporal bone(zygomatic process)

Vomer

Inferior view of skull (mandible removed)

Temporal bone

Parietal bone

Palatine bone

axial skeleton: the skull slides by vince austin; figures from marieb & hoehn 8 th ed.;...

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