© 2013 Pearson Education, Inc. Skeletal System Composed of bones, cartilages, joints, ligaments 20%...

© 2013 Pearson Education, Inc.

Skeletal System

• Composed of bones, cartilages, joints, ligaments

• 20% of body mass

• Two major parts– Axial– Appendicular


The Axial Skeleton

• Consists of 80 bones

• Three major regions– Skull– Vertebral column– Thoracic cage


Figure 7.1a The human skeleton.

Anterior view

Radius

Rib

Skull

Thoracic cage(ribs andsternum)

Vertebralcolumn

Sacrum

TarsalsMetatarsalsPhalanges

Ulna

Vertebra

Humerus

Sternum

Scapula

Clavicle

Facial bones

Cranium

Fibula

Tibia

PatellaFemurMetacarpalsPhalanges

Carpals


Metacarpals

Radius

Rib

Posterior view

Fibula

Tibia

Femur

Phalanges

Carpals

Ulna

Vertebra

Humerus

Sternum

Scapula

Clavicle

Cranium

Bones ofpectoralgirdle

Upperlimb

Bones ofpelvicgirdle

Lowerlimb

Figure 7.1b The human skeleton.


The Skull

• Formed by two sets of bones1. Cranial bones (cranium)

• Enclose the brain in the cranial cavity• Provide sites of attachment for head and neck

muscles


The Skull

2. Facial bones– Framework of face– Cavities for special sense organs for sight,

taste, and smell– Openings for air and food passage– Sites of attachment for teeth and muscles of

facial expression


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

Bones of cranium

Coronal suture

Squamous suture

Lambdoidsuture

Facialbones

Cranial and facial divisions of the skull


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

Anterior cranialfossa

Middle cranialfossa

Posterior cranialfossa

Superior view of the cranial fossae


Skull Geography

• Cranial cavity

• Middle and internal ear cavities

• Nasal cavity

• Orbits

• 85 named openings– Foramina, canals, fissures


Frontalbone

Zygomaticbone

Ethmoidbone

Inferiornasalconcha

Maxilla

Vomer

Mandible

Cranial cavity

Orbit Orbit

Oral cavity

Frontalsinus

Ethmoidalair cells

Maxillarysinus

Nasalcavity

Figure 7.3 Major cavities of the skull, frontal section.


Eight Cranial Bones

• Frontal bone

• Parietal bones (2)

• Occipital bone

• Temporal bones (2)

• Sphenoid bone

• Ethmoid bone


Frontal Bone

• Anterior portion of cranium

• Superior wall of orbits

• Contains air-filled frontal sinus


Parietal bone

Squamous part of frontal boneNasal boneSphenoid bone(greater wing)

Temporal boneEthmoid boneLacrimal bone

Zygomatic bone

Infraorbital foramen

Maxilla

Mandible

Mentalforamen

Frontal bone

GlabellaFrontonasal sutureSupraorbital foramen(notch)Supraorbital marginSuperior orbitalfissureOptic canalInferior orbitalfissure

Middle nasal conchaPerpendicular plate

Ethmoidbone

Inferior nasal concha

Vomer

Suturalbone

Sagittal suture

Parietal bone Mandibularsymphysis

Lambdoidsuture

Occipital bone

Superior nuchal line

Externaloccipital protuberance

Occipitomastoidsuture External

occipitalcrest

Occipitalcondyle

Mastoidprocess oftemporal bone

Inferiornuchal line

Anterior view

Posterior view

Figure 7.4 Anatomy of the anterior and posterior aspects of the skull.


Parietal Bones and Major Associated Sutures

• Superior and lateral aspects of cranial vault• Four sutures mark articulations of parietal bones

with frontal, occipital, and temporal bones:1. Coronal suture—between parietal bones and frontal

bone

2. Sagittal suture—between right and left parietal bones

3. Lambdoid suture—between parietal bones and occipital bone

4. Squamous (squamosal) sutures—between parietal and temporal bones on each side of skull


Figure 7.5a Bones of the lateral aspect of the skull, external and internal views.

Coronal suture

Parietal bone

Temporal bone

Lambdoidsuture

Squamoussuture

Zygomaticprocess

Occipitalbone

OccipitomastoidsutureExternal acousticmeatusMastoid processStyloid process

Condylar processMandibular notch

Mandibular ramus

Frontal boneSphenoid bone(greater wing)

Ethmoid bone

Lacrimal bone

Lacrimal fossa

Nasal bone

Zygomatic boneMaxilla

Alveolarprocesses

MandibleMental foramen

Coronoid processMandibular angleExternal anatomy of theright side of the skull


Figure 7.5b Bones of the lateral aspect of the skull, external and internal views.

Coronal suture

Parietal bone

SquamoussutureTemporal bone

ZygomaticprocessLambdoidsutureOccipitalbone

OccipitomastoidsutureExternal acousticmeatusMastoid process

Styloid process

CondylarprocessMandibular angle


Ethmoid bone

Lacrimal bone

Nasal bone

Lacrimal fossa

Zygomatic bone

Coronoid process

Maxilla

Alveolarprocesses


Mandibular notchMandibular ramus

Photograph of right side of skull


Figure 7.5c Bones of the lateral aspect of the skull, external and internal views.

Nasal boneCrista galli

Sella turcicaof sphenoidbone

Internal acousticmeatus

External occipitalprotuberance

Occipitomastoidsuture

Occipitalbone

Lambdoidsuture

Temporalbone

Squamoussuture

Parietal bone

Coronal sutureFrontal bone

Sphenoid bone

Frontal sinus

Sphenoidal sinusEthmoid bone(perpendicular plate)

GreaterwingLesserwing

Palatine bone

Vomer

Maxilla

Palatine process of maxilla

Mandibularforamen

Pterygoidprocess ofsphenoid bone

Incisive fossa

Alveolar processes

Mandible

Midsagittal section showing the internal anatomy of the left half of skull


Figure 7.5d Bones of the lateral aspect of the skull, external and internal views.

Petrous partof temporalbone

External occipitalprotuberance

Internal acousticmeatus

Sella turcica andsphenoidal sinus

Greater wing ofsphenoid bone

Lesser wing ofsphenoid bone

Frontal sinusCrista galli

Ethmoid bone(perpendicular plate)

Palatine bone

Photo of skull cut through the midline, same view as in (c)


Occipital Bone

• Most of skull's posterior wall and posterior cranial fossa

• Articulates with 1st vertebra

• Sites of attachment for many neck and back muscles


Figure 7.4b Anatomy of the anterior and posterior aspects of the skull.

Suturalbone

Sagittal suture

Parietal bone


Inferiornuchal line

Occipitalcondyle

Externaloccipitalcrest




Occipital bone

Lambdoidsuture

Posterior view


Figure 7.6a Inferior aspect of the skull, mandible removed.

Hardpalate

Maxilla(palatine process)

Palatine bone(horizontal plate)

Zygomatic bone

Temporal bone(zygomatic process)

Vomer

MandibularfossaStyloid process

Mastoid process

Temporal bone(petrous part)Basilar part of theoccipital boneParietal bone

External occipital crestExternal occipitalprotuberance

Inferior view of the skull (mandible removed)

Incisive fossaIntermaxillary sutureMedian palatine sutureInfraorbital foramenMaxilla

Sphenoid bone(greater wing)

Foramen ovale

Foramen spinosumForamen lacerumCarotid canalExternal acoustic meatusStylomastoidforamenJugular foramen

Occipital condyle

Inferior nuchal line

Superior nuchal lineOccipital bone

Foramen magnum


Figure 7.6b Inferior aspect of the skull, mandible removed.

Zygomaticarch

Foramen ovale

Foramen lacerum

Foramen spinosum

Carotid canal

Styloid process

Jugular foramen

Occipital condyle

Foramen magnum

Superior nuchalline

Hard palate

Mandibularfossa

Mastoidprocess

Photo of inferior view of the skull


Temporal Bones

• Inferolateral aspects of skull and parts of cranial floor

• Four major regions– Squamous– Tympanic– Mastoid– Petrous


Figure 7.8 The temporal bone.

External acousticmeatus

Squamouspart

Petrouspart Mastoid process

Styloid process

Zygomaticprocess

Mandibularfossa

Tympanicpart



Hardpalate



Zygomatic bone


Vomer


Mastoid process






Foramen ovale


Occipital condyle



Foramen magnum


Figure 7.7a The base of the cranial cavity.

Foramen ovale

Cribriform plateCrista galli

Lesser wingGreater wing

ViewEthmoidbone

Anterior cranial fossa

Sphenoid

Hypophyseal fossaof sella turcicaMiddle cranialfossaTemporal bone(petrous part)

Posteriorcranial fossa

Parietal bone

Occipital bone

Foramen magnum

Superior view of the skull, calvaria removed

Frontal bone

Cribriform foramina

Optic canal

Foramen rotundum

Foramen spinosum

Foramen lacerum

Internal acoustic meatus

Jugular foramen

Hypoglossal canal


Figure 7.7b The base of the cranial cavity.

Crista galli Cribriform plateEthmoid

boneAnterior cranial fossa

Sphenoid Lesser wingGreater wing

Hypophyseal fossaof sella turcica

Middle cranialfossa

Temporal bone(petrous part)


Parietal bone

Occipital bone

Foramen magnum

Frontal bone

Cribriform foramina

Optic canal

Foramen rotundumForamen ovaleForamen spinosumForamen lacerum

Jugular foramen



Sphenoid Bone

• Complex, bat-shaped bone

• Keystone bone– Articulates with all other cranial bones

• Three pairs of processes– Greater wings– Lesser wings– Pterygoid processes


Figure 7.9a The sphenoid bone.

Opticcanal

Lesser wing

Superiororbitalfissure

ForamenrotundumForamenovaleForamenspinosumBody of sphenoid

Greaterwing

Hypophyseal fossa ofsella turcica

Superior view


Figure 7.9b The sphenoid bone.

Lesser wing

Superior orbitalfissure

Pterygoidprocess

Body of sphenoid

Greaterwing

Posterior view


Ethmoid Bone

• Deepest skull bone

• Superior part of nasal septum, roof of nasal cavities

• Contributes to medial wall of orbits

• Crista galli for dural attachment


Figure 7.10 The ethmoid bone.

Crista galli

Cribriform platewith cribriformforamina

Leftlateralmass

Orbitalplate

Ethmoidal air cells

Perpendicularplate

Middlenasal concha


Figure 7.4a Anatomy of the anterior and posterior aspects of the skull.

Parietal bone



Zygomatic boneInfraorbital foramen

Maxilla

Mandible

Mentalforamen

Frontal bone

GlabellaFrontonasal sutureSupraorbital foramen(notch)Supraorbital marginSuperior orbitalfissureOptic canal

Inferior orbitalfissure



Vomer

Ethmoidbone

MandibularsymphysisAnterior view


Figure 7.7a The base of the cranial cavity.

Foramen ovale

Cribriform plateCrista galli

Lesser wingGreater wing

ViewEthmoidbone

Anterior cranial fossa

Sphenoid

Hypophyseal fossaof sella turcicaMiddle cranialfossaTemporal bone(petrous part)


Parietal bone

Occipital bone

Foramen magnum


Frontal bone

Cribriform foramina

Optic canal

Foramen rotundum

Foramen spinosum

Foramen lacerum

Internal acoustic meatus

Jugular foramen

Hypoglossal canal


Sutural Bones

• Tiny irregularly shaped bones that appear within sutures


Figure 7.4b Anatomy of the anterior and posterior aspects of the skull.

Suturalbone

Sagittal suture

Parietal bone


Inferiornuchal line

Occipitalcondyle

Externaloccipitalcrest




Occipital bone

Lambdoidsuture

Posterior view


• Lacrimal bones (2)• Palatine bones (2)• Vomer• Inferior nasal

conchae (2)

Fourteen Facial Bones

• Mandible• Maxillary bones

(maxillae) (2)• Zygomatic bones (2)• Nasal bones (2)


Mandible

• Lower jaw

• Largest, strongest bone of face

• Temporomandibular joint– Only freely movable joint in skull


Figure 7.11a Detailed anatomy of the mandible and the maxilla.

Temporomandibularjoint

Mandibular fossaof temporal bone

Coronoidprocess

Condylarprocess

Mandibular notch

Mandibular foramen

AlveolarprocessMentalforamen

Ramusof mandible

Mandibularangle Body of mandible

Mandible, right lateral view


Maxillary Bones

• Medially fused to form upper jaw and central portion of facial skeleton

• Keystone bones– Articulate with all other facial bones except

mandible

• Contain maxillary sinuses– Largest of paranasal sinuses


Figure 7.11b Detailed anatomy of the mandible and the maxilla.

ArticulateswithfrontalboneFrontalprocess

InfraorbitalforamenAnteriornasal spineAlveolarprocess

Orbital surface

Zygomaticprocess(cut)

Maxilla, right lateral view



Parietal bone




Maxilla

Mandible

Mentalforamen

Frontal bone





Vomer

Ethmoidbone

Anterior view

Mandibularsymphysis



Hardpalate



Zygomatic bone


Vomer


Mastoid process






Foramen ovale


Occipital condyle



Foramen magnum


Zygomatic Bones

• Cheekbones

• Inferolateral margins of orbits



Parietal bone




Maxilla

Mandible

Mentalforamen

Frontal bone





Vomer

Ethmoidbone

Anterior view

Mandibularsymphysis


Nasal Bones and Lacrimal Bones

• Nasal bones– Form bridge of nose

• Lacrimal bones– In medial walls of orbits– Lacrimal fossa houses lacrimal sac


Figure 7.5a Bones of the lateral aspect of the skull, external and internal views.

Coronal suture

Parietal bone

Temporal bone

Lambdoidsuture

Squamoussuture

Zygomaticprocess

Occipitalbone

OccipitomastoidsutureExternal acousticmeatusMastoid processStyloid process

Condylar processMandibular notch

Mandibular ramus


Ethmoid bone

Lacrimal bone

Lacrimal fossa

Nasal bone

Zygomatic boneMaxilla

Alveolarprocesses


Coronoid processMandibular angleExternal anatomy of theright side of the skull


• Vomer– Plow shaped – Inferior part of

nasal septum

Palatine Bones and Vomer

• Palatine bones– Posterior one-third

of hard palate– Posterolateral walls

of the nasal cavity– Small part of the

orbits



Hardpalate



Zygomatic bone


Vomer


Mastoid process






Foramen ovale


Occipital condyle



Foramen magnum


Figure 7.13b Bones of the nasal cavity.

Ethmoidbone

Crista galliCribriformplate

Sella turcica

Sphenoidalsinus

Hardpalate

Palatine bone

Palatine processof maxilla

Frontal sinus

Nasal bone

Perpendicular plateof ethmoid bone

Septal cartilage

Vomer

Alveolar processof maxilla

Nasal cavity with septum in place showing the contributions of theethmoid bone, the vomer, and septal cartilage


Inferior Nasal Conchae

• Form part of lateral walls of nasal cavity

• Largest of three pairs of conchae


Frontal sinus

Superior, middle, andinferior meatus

Sphenoidbone

SphenoidalsinusPterygoidprocess

Palatine bone(perpendicularplate)

Palatine bone (horizontal plate)

Superiornasal conchaMiddlenasal concha

Inferior nasal conchaNasal bone

Anterior nasal spine

Ethmoidbone

Bones forming the left lateral wall of the nasal cavity(nasal septum removed)

Maxillary bone(palatine process)

Figure 7.13a Bones of the nasal cavity.


Orbits

• Cavities that encase eyes and lacrimal glands

• Sites of attachment for eye muscles

• Formed by parts of seven bones– Frontal, sphenoid, zygomatic, maxilla,

palatine, lacrimal, and ethmoid


Figure 7.12a Bones that form the orbits.

Photograph, right orbit


Figure 7.12b Bones that form the orbits.

Roof of orbit Supraorbital notch

Superiororbital fissure

Optic canal • Lesser wing of sphenoid bone• Orbital plate of frontal bone Medial wall

Lateral wall of orbit • Zygomatic process of frontal bone• Greater wing of sphenoid bone• Orbital surface of zygomatic bone

Inferior orbital fissure

Zygomatic bone

• Sphenoid body• Orbital plate of ethmoid bone• Frontal process of maxilla• Lacrimal bone

Nasal bone

Floor of orbit• Orbital process of palatine bone• Orbital surface of maxillary bone• Zygomatic bone

Contribution of each of the seven bones forming the right orbit

Infraorbital groove

Infraorbitalforamen


Nasal Cavity

• Roof, lateral walls, and floor formed by parts of four bones– Ethmoid– Palatine bones– Maxillary bones– Inferior nasal conchae

• Nasal septum of bone and hyaline cartilage– Perpendicular plate of ethmoid – Vomer – Anterior septal cartilage


Frontal sinus

Superior, middle, andinferior meatus

Sphenoidbone

SphenoidalsinusPterygoidprocess

Palatine bone(perpendicularplate)

Palatine bone (horizontal plate)

Superiornasal conchaMiddlenasal concha

Inferior nasal conchaNasal bone

Anterior nasal spine

Ethmoidbone

Bones forming the left lateral wall of the nasal cavity(nasal septum removed)

Maxillary bone(palatine process)

Figure 7.13a Bones of the nasal cavity.


Figure 7.13b Bones of the nasal cavity.

Ethmoidbone

Crista galliCribriformplate

Sella turcica

Sphenoidalsinus

Hardpalate

Palatine bone

Palatine processof maxilla

Frontal sinus

Nasal bone

Perpendicular plateof ethmoid bone

Septal cartilage

Vomer

Alveolar processof maxilla

Nasal cavity with septum in place showing the contributions of theethmoid bone, the vomer, and septal cartilage


Paranasal Sinuses

• Mucosa-lined, air-filled spaces

• Lighten skull

• Enhance resonance of voice

• Warm and humidify air

• Found in frontal, sphenoid, ethmoid, and maxillary bones


Figure 7.14a Paranasal sinuses.

Frontal sinus

Ethmoidal air cells(sinus)

Sphenoidal sinus

Maxillary sinus

Anterior aspect


Frontal sinus

Ethmoidal air cells

Sphenoidal sinus

Maxillary sinus

Medial aspect

Figure 7.14b Paranasal sinuses.


Hyoid Bone

• Not bone of skull

• Does not articulate directly with another bone

• Movable base for tongue

• Site of attachment for muscles of swallowing and speech


Greater horn

Lesser horn

Body

Figure 7.15 The hyoid bone, anterior view.

© 2013 Pearson Education, Inc. Skeletal System Composed of bones, cartilages, joints, ligaments 20%...

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