Final-Osteology Med-Jj [Compatibility Mode]

8/6/2019 Final-Osteology Med-Jj [Compatibility Mode]

1/64

OSTEOLOGYOSTEOLOGY

The Skull


2/64


3/64

6/24/2011 3

The SkullThe Skull

Frontal coronal sutureParietal

Sphenoid

Temporal

Occipital


4/64

6/24/20114

Mandible

maxilla

Nasal

InferiorNasalconchae

Vomer

The SkullThe Skull

Lacrimal

Zygomatic

Inferior Nasal

Conchae

VomerMandible

Maxilla

Nasal


5/64

6/24/2011 5

Frontalbone

Nasion Glabella

Squamous (flat) portionforms the skeleton of theforehead

Fontal bone forms the roofof the orbit

Nasion is an area wherethe frontal bone intersectswith the nasal bones

Glabella- smooth, slightlydepressed area located

just superior to the nasion

Frontal BoneFrontal Bone

Squamousportion

Orbitalportion

Nasion

Glabella

FrontalBone


6/64

6/24/2011 6

Supraorbital margin-

marks the boundarybetween the squamousand orbital portions

Supraorbital notch orforamen is for the passageof the supraorbital nerveand vessels

A prominent ridge justsuperior to the supraorbitalmargin is the superciliaryarch (more pronounced inmales)

Zygomatic process of thefrontal bone articulateswith the zygomatic bone

Supraorbitalmargin

Supraorbitalnotch

Superciliaryarch

Zygomaticprocess

Frontal BoneFrontal Bone


7/64

6/24/2011 7

Frontalprocess

Temporalprocess

Zygomaticofacialforamen

Cheek bones

Forms a portion of the lateralwall of the orbit

Frontal Process of thezygomatic bone articulates withthe frontal bone

Temporal process of the

zygomatic bone articulates withthe temporal bone

Zygomaticofacial foramen-small foramen for passage of

the zygomaticofacial nerve

Zygomatic BonesZygomatic Bones


8/64

6/24/2011 8

Piriformaperture

Alveolarprocess

Infraorbitalforamen

Forms the upper jaw

Alveolar processes of themaxillae includes thesockets and supportingbone for the maxillary teeth

Maxillae form the floor ofthe orbit

Large infraorbitalforamen for passage of theinfraorbital nerve & vessels

Surrounds most of thepear-shaped piriformaperture

MaxillaeMaxillae

Maxilla


9/64

6/24/2011 9

Frontal processes of the

maxillae articulates withthe frontal bone

Zygomatic processes ofthe maxillae articulateswith the zygomatic bones

Anterior nasal spine-sharp prominence atinferior aspect of thepiriform aperture

Intermaxillary suture-site where the two maxillaare united in the medianplane

MaxillaeMaxillae

frontalprocess

Anteriornasalspine

Intermaxillarysuture

Zygomaticprocess


10/64

6/24/2011 10

Seen within the piriformaperture are the scrolledmiddle nasal conchae(part of the ethmoid bone)& the inferior nasal

conchae

Vomer bone along withthe perpendicular plateof the ethmoid bonewhich together form thebony nasal septum canalso be identified with thepiriform aperture

Vomer

Middle & Inferiorconcha

Perpendicularplate


11/64

6/24/2011 11

Ramus

Body

Mentalforamen

Mental protuberance

Alveolarprocess

U-shaped bone with alveolarprocess that houses themandibular teeth

Mental foramen- locatedinferior to 2 nd premolar forpassage of the mental nerve

and vessels Mental protuberance- atriangular elevation of bonethat forms the prominence ofthe chin

Mental tubercle- located justlateral to the protuberance

Body is the horizontalportion

Ramus is the vertical portion

MandibleMandible


12/64

OsteologyOsteology

Lateral Aspect of the Skull


13/64

6/24/2011 13

1. Parietal bone2. Frontal bone3. Occipital bone

4. Temporal bone5. Sphenoid bone6. Mandible7. Zygomatic bone8. Maxillae9. Lacrimal bone10. Nasal bone

Lateral Aspect of the SkullLateral Aspect of the Skull

1.

4.

2.

3.

6.

9.

8.

10 .

5.

7.


14/64

6/24/2011 14

Parietal

Coronal suture

LambdoidsutureTemporal

lines

Paired bones that form thelateral & superior cranium

Temporal Lines- markthe attachment site of thetemporalis muscle &fascia

Articulates with frontalbone via coronal suture

Articulates with occipitalbone via lambdoid suture

Pterion -site where 4cranial bones articulate-important clinical

implications

Parietal BonesParietal Bones

pterion


15/64

6/24/2011 15

Mastoidprocess

Zygomatic arch

Paired bones that formthe inferior lateral aspectof skull

Temporal bone is

described as having a flatsquamous portion and amastoid process (site ofattachment of severalmuscles)

Zygomatic arch extendsanteriorly to articulatewith the zygomatic bone

Temporal BonesTemporal Bones

Squamous


16/64

6/24/2011 16

Externalacousticmeatus

Styloid process

External acousticmeatus (ear canal) andthe pointed styloidprocess are consideredto be located thetympanic portion of thetemporal bone

Styloid process servesas the attachment site forseveral muscles and thestylohyoid ligament



17/64

6/24/2011 17

Articulartubercle

Mandibularfossa

Mandible and a portion ofthe zygomatic archremoved in this view

Located on the inferioraspect of the arch is asmall bony protrusion-articular tubercle that isimportant in themechanics of the TMJ

Mandibular fossa- deep

recess that accepts thecondyle of the mandible-also important region ofthe TMJ



18/64

6/24/2011 18

Forms major portion of thecheek

Temporal process thatarticulates with the thezygomatic arch

Frontal process thatarticulates with the frontalbone

Zygomaticofacialforamen small foramengenerally visible

Zygomatic boneZygomatic bone

Temporal process

Frontal process

Zygomatic arch

Zygomaticofacialforamen


19/64

6/24/2011 19

Lambdoidsuture

ExternalOccipitalprotuberance

Forms the posterioraspect of the skull

Articulates with theparietal bone via thelambdoid suture

Prominent palpableelevation locatedposteriorly is the externaloccipital protuberance

Occipital BoneOccipital Bone


20/64

6/24/2011 20

Sphenoid Bone

Irregular shaped bone thatforms a portion of theorbit, lateral aspect of skulland a portion of the cranialbase

Sphenoid can be dividedinto 4 parts:1. Greater wing2. Lesser wing3. Pterygoid processes

4. Body Some portions of the

sphenoid can only beseen inside the cranialcavity

Sphenoid BoneSphenoid Bone


21/64

6/24/2011 21

Greater wi ng

Pterygoidprocess

Pterygoidhamulus

Portion of zygomatic arch andmandible removed in this view

Greater wing articulates withthe temporal, parietal & frontalbones at the pterion

Pterygoid processes are twothin plates of bone that serveas attachment sites for muscles

Pterygoid hamulus -smallhook of bone extending fromthe medial pterygoid plate-tensor veli palatini tendoncourses around this

4 portions of Sphenoid4 portions of Sphenoid BoneBone


22/64

6/24/2011 22

Tuberosity of maxilla

Alveolarforamen

Pterygomaxillary

Fissure

Portion of zygomatic arch andmandible removed in this view

Posterior aspect of themaxillae is referred to as thetuberosity of maxillae

Small alveolar foramina forthe posterior superior alveolarnerves & vessels

Pterygomaxillary fissure -tear-drop shaped fissurebetween the sphenoid andtuberosity of the maxillae

Pterygopalatine fossa is asmall but important spacelocated medial to the fissure

MaxillaeMaxillae


23/64

6/24/2011 23

Nasalspine

Nasalbone

Lacrimal bone

Lateral Aspect of SkullLateral Aspect of Skull Nasal bone can also

identified as it articulateswith the frontal bone andthe maxillae

Lacrimal bone - whichhouses the lacrimal sacvan be identified within theorbit

Prominent anterior nasalspine at the inferioraspect of the piriformaperture


24/64

6/24/2011 24

Angle

Condylarprocess

Coronoidprocess

MandibleMandible

Condylar process islocated at the superiorpart of the ramus andinvolved in the articulationof the mandible with thetemporal bone (TMJ)

Coronoid process islocated just anterior andserves as the attachmentsite for the temporalismuscle

Angle of mandible isbetween the ramus andbody


25/64

6/24/2011 25

Ramus

Body

Alveolar P art (crest)

Condylar Process

Coronoid process

Mental foramen

Lingula

Mandibularforamen

Mylohyoid line

Infant

MandibleMandible


26/64

6/24/2011 26

Body

Ramus

Condylar process

Mandibular notch

Bone loss due to tooth loss

Mental spines

MandibleMandible


27/64

6/24/2011 27

Coronalsuture

Sagittalsuture

Emissaryforamen

Lambdoidsuture

CalvariaCalvaria

Emissary foramen- small,inconsistent (not alwayspresent) foramina forpassage of emissary veins

Bregma - is the landmarkformed by the intersection ofthe sagittal & coronal sutures

Lambda- is the landmarkformed by the intersection ofthe sagittal & lambdoidsutures

Bregma

Lambda


28/64

6/24/2011 28

Groove for superiorsagittal sinus

Grooves formiddlemeningealartery

Diploe

Granular

foveolae

CalvariaCalvaria Inferior aspect of the skull

cap presents severalfeatures:

Vascular grooves forbranches of the middlemeningeal artery

Granular Foveolae - pitsformed by arachnoidgranulations (site of CSFtransfer)

Groove for the superiorsagittal sinus -largevenous channel within thedura mater

Diploe - cancellous bonecontaining red marrow


29/64

Infant SkullInfant Skull

Superior & Lateral Aspects


30/64

6/24/2011 30

Anterior

Posterior

SphenoidalMastoid

Infant SkullInfant Skull Bones forming the calvaria &

some parts of the cranialbase develop byintramembranousossification

Whereas-most parts of the

cranial base develop byendochondral ossification Bones in the infant skull are

separated by areas of fibroustissue membranes- thefontanelles:

Anterior Posterior Mastoid sphenoidal


31/64

6/24/2011 31

Anteriorfontanelle

Posteriorfontanelle

Infant CalvariaInfant Calvaria Anterior Fontanelle (soft

spot) is the future site ofthe bregma

By about 18-24 months-the surrounding bonesfuse together and is no

longer palpable

Posterior Fontanelle istriangular and marks thefuture site of the lambda

Fusion of surroundingbones occurs by about 12months

Fontanelles- mem branous gaps (soft spots) in skull that permit grow th


32/64

6/24/2011 32

Anterior Posterior

SphenoidalMastoid

Infant SkullInfant Skull Mastoid & sphenoidal

fontanelles fuse early ininfancy

Palpation of fontanellesduring infancy enablesphysicals to determine:

1. Growth progress of thefrontal & parietal bones

2. Degree of hydration of theinfant (a depressedfontanelle indicates

dehydration)3. Level of intracranial

pressure-bulging fontanelleindicates increasedpressure on the brain


33/64

OsteologyOsteology

External Aspect of the Cranial

Base


34/64

6/24/2011 34

1

2

3

45

6

Cranial BaseCranial Base

Inferior aspect of the skullpresents six different bones:

1. Palatine processes of themaxillae

2. Palatine bone3. Sphenoid bone4. Vomer5. Temporal6. Occipital bone Numerous foramina can also be

identified


35/64

6/24/2011 35

Cranial BaseCranial Base- - PalatePalate

Hard palate is formed bythe palatine processesof the maxillae and thehorizontal plates of thepalatine bone

Small prominenceprojecting posteriorly formthe hard palate in themedian plane is theposterior nasal spine

Horizontalplate of thePalatine bone

Palatineprocesses

Posteriornasalspine


36/64

6/24/2011 36

Cranial BaseCranial Base- - PalatePalate

Posterior to the centralincisors is a smalldepression- incisive fossawith a pair of canals-incisive canals for thepassage of thenasopalatine nerves

Posterolaterally are thegreater & lesser palatineforamen for passage ofthe nerves & vessels ofthe same name

Greater and

LesserPalatineforamina

Incisivecanals


37/64

6/24/2011 37

Choanae

Vomer

Cranial BaseCranial Base- -VomerVomer

Vomer -thin, flat unpairedbone in the midline thatforms a major portion ofthe bony nasal septum

On either side of thevomer are two largeopenings- choanae(posterior nasal apertures)


38/64

6/24/2011 38

Greaterwing

Lateralpterygoidplate

Medialpterygoidplate

Cranial BaseCranial Base- - SphenoidSphenoid

Three parts of thesphenoid bone can beappreciated on theinferior aspect of skull:

1. Greater wing

2. Medial pterygoid plate

3. Lateral pterygoid plate

Pterygoid fossa isbetween the twopterygoid plates


39/64

6/24/2011 39

Cranial BaseCranial Base- - SphenoidSphenoid

Foramen ovale forpassage of themandibular division (V3)of the trigeminal nerve

Foramen spinosum - forpassage of the middlemeningeal artery

Groove for thepharyngotympanic(auditory) tube liesmedial to spinosum

Foramenovale

Foramenspinosum

AuditoryTube-groove


40/64

6/24/2011 40

Cranial BaseCranial Base- - TemporalTemporal

Mastoid process-prominence locatedposteriorly on the temporalbone

Mastoid serves as theattachment site for theSCM and posterior belly ofthe digastric muscles

External acousticmeatus (EAM) is located

just anterior to the mastoid

EA M

Mastoidprocess


41/64

6/24/2011 41

Mandibularfossa

Styloidprocess


Styloid process- thinbony process extendinginferior & anteriorly

Styloid serves asattachment site fornumerous muscles &ligaments

Mandibular fossa-articular surface thataccepts the condyle of themandible forming the TMJ


42/64

6/24/2011 42


Two important foramencan be identified on theinferior aspect of thetemporal bone:

Stylomastoid foramen-located between themastoid & styloidprocesses is a smallforamen for the passageof the facial nerve (CN VII)

Carotid canal- passage forthe internal carotid arteryinto the cranial cavity

Carotid canal

Stylomastoidforamen


43/64

6/24/2011 43

1

2

3

Foramenmagnum

Cranial BaseCranial Base- - OccipitalOccipital

Occipital bone forms theposterior and inferioraspects of the skull

Foramen Magnum - a

large foramen forpassage of the spinalcord

Foramen magnumdivides the occipital boneinto 3 parts:

1. Basilar Region2. Condylar Region3. Squamous Region


44/64

6/24/2011 44

Pharyngealtubercle

Foramenlacerum


Basilar portion presentsa small tubercle-pharyngeal tubercle forattachment of thepharyngeal constrictors

Foramen lacerum(jagged-shaped) islocated lust lateral to the

basilar portion


45/64

6/24/2011 45

Jugularforamen

Occipitalcondyle

Hypoglossalcanal


Condylar portion presentsthe occipital condyles thatarticulate with the atlas

Jugular foramen- largeforamen between theoccipital & temporal bonesfor passage of cranialnerves: IX, X, XI and theinternal jugular vein

Hypoglossal canal forpassage of the hypoglossalnerve (CN XII)


46/64

6/24/2011 46

Externaloccipitalprotuberance

Superior & inferior

nuchal lines


Squamous portionpresents the palpableexternal occipitalprotuberance

Superior & inferiornuchal lines projectlaterally and are sitesfor muscularattachments


47/64

OsteologyOsteology

Internal Aspect of the CranialBase


48/64

6/24/2011 48

Anterior cranial fossa

Middle cranial fossa

Posterior cranial fossa

Cranial BaseCranial Base

Internal aspect of thecranial base is dividedinto three major regionsor fossae:

1. Anterior cranial fossa2. Middle cranial fossa3. Posterior cranial fossa

These three fossae lie atdifferent levels and formthe bowl-shaped floor ofthe cranial cavity


49/64

6/24/2011 49

Ethmoid

Orbital portion of the frontal bone

Lesser wing of the sphenoid

Anterior Cranial FossaAnterior Cranial Fossa

Frontal lobes of thebrain occupies theanterior cranial fossa

Fossa is formed by the:1. Orbital portion of the

frontal bone2. Ethmoid bone in the

middle3. Lesser wing of the

sphenoid


50/64

6/24/2011 50

Cristagalli

Frontal crest

Foramen cecum


Frontal crest- a medianbony extension from thefrontal bone

Foramen cecum is locatedat the base of the crest and

is a small foramen forpassage a vessels duringdevelopment

Crista galli- ridge of boneprojecting superiorly fromthe ethmoid bone andserves as the attachmentfor the cerebral falx


51/64

6/24/2011 51


On either side of thecrista galli is a sievelikeCribriform plate forpassage of the olfactoryaxons into the cranialcavity

Optic canal for passageof the optic nerve (CN II)and the ophthalmicartery can be

appreciated within thelesser wing of thesphenoid

Cribriform plate

Optic canal


52/64

6/24/2011 52

Greater wingof sphenoid

Squamousportion temporalbone

Petrous portiontemporal bone

Middle Cranial FossaMiddle Cranial Fossa

Temporal lobes of thebrain occupy the middlecranial fossa

Fossa is formed by the:1. Greater wing of the

sphenoid2. Squamous portion of the

temporal bone

3. Petrous portion of thetemporal bone


53/64

6/24/2011 53


Sella turcica- the saddle-like bony formationlocated on the superioraspect of the body of thesphenoid

Sella turcica is surroundedby anterior & posterior

clinoid processes

Sellaturcica Anterior and

Posterior clinoids


54/64

6/24/2011 54


Sella turcica iscomposed of three parts:

1. Hypophyseal fossa

(pituitary fossa)2. Tuberculum sellae(saddle horn)

3. Dorsum Sellae (back ofthe saddle)

Sella turcica- essentiallyhouses and guards thepituitary gland

Hypophyseal fossa

Tuberculum sellae

Dorsum sellae


55/64


56/64

6/24/2011 56

Foramen spinosum

Foramenlacerum

Petrosal grooves

Middle Cranial FossaMiddle Cranial Fossa4. Foramen spinosum

which transmits the middlemeningeal artery

5. Foramen lacerum-nothing is transmittedvertically thru this foramenalthough the internalcarotid artery and somenerves pass across theforamen horizontally

Grooves for the greater &lesser petrosal nervesare located along theanterior slope of thepetrous portion of thetemporal bone


57/64

6/24/2011 57

Arcuate em inence

Trigeminal impression


Petrous portion of the

temporal bone housesthe middle and inner earcavities

Arcuate eminence-marks the roof of theanterior semicircularcanal of the inner earcavity

Trigeminal impression is

located just anteromedialthe eminence-whichmarks the location of thesensory ganglion of thetrigeminal nerve


58/64

6/24/2011 58

Posterior Cranial FossaPosterior Cranial Fossa

The largest & deepest ofthe three fossae

Cerebellum , pons and

medulla occupy theposterior fossa

Formed mainly by theoccipital bone and the

petrous & mastoidportions of the temporalbone

Occipitalbone Temporal bone

Petrous portion


59/64

6/24/2011 59

clivus

Occipital crest

Internal occipitalprotuberance


Clivus marks theanterior portion of theoccipital bone

Foramen magnum -

large foramen that marksthe transition from themedulla to the spinalcord

Posterior to the foramenmagnum is the internaloccipital crest andinternal occipitalprotuberance


60/64

6/24/2011 60

TransverseSinus groove

Groove for theSigmoid sinus

Jugularforamen

Broad grooves show the

horizontal course of thetransverse and S-shapedsigmoid sinuses (both duralvenous sinuses)

Sigmoid sinus empties intothe large jugular foramenwhich also transmits severalcranial nerves:

1. Glossopharyngeal (CN IX)

2. Vagus (CN X)3. Accessory (CN XI)



61/64

6/24/2011 61

Hypoglossalcanal

Internalacousticmeatus


Internal acoustic meatus islocated just anterosuperior tothe jugular foramen

Internal acoustic meatustransmits the facial nerve(CN VII) andvestibulochochlear nerve(CN VIII) along with thelabyrinthine artery

Hypoglossal canal for thehypoglossal nerve (CN XII)lies superior to the margin ofthe foramen magnum


62/64

6/24/2011 62

Cribrifrom plate-CN I

Optic Canal CN I I

Superior Orbital FissureCN II I, IV, V1 & VI

Hypoglossal CanalCN XII

Jugular Foramen- CN IX, X and XI

Internal Acoustic Meatus-CN VII & VIII

Foramen Rotundum- CN V2

Foramen Ovale-CN V3


63/64

6/24/2011 63

1

23

457

mediallateral

superior

inferior

Osteology of the OrbitOsteology of the Orbit

Seven bones articulate tomake each orbit:

1. Frontal

2. Zygomatic3. Maxillary4. Lacrimal5. Ethmoid

6. Palatine7. Sphenoid

6


64/64

6/24/2011 64

Inferiororbitalfissure & groove

Optic canal

Superiororbitalfissure

Ethmoidalforamina

Osteology of the OrbitOsteology of the Orbit Optic canal- transmits the

optic nerve andophthalmic artery

Superior orbital fissure-transmits CN III, IV, V1 &VI

Inferior orbital fissure &groove- transmits theinfraorbital vessels &nerve

Anterior & posteriorethmoidal foramina-transmits vessels & nerveswith same name

Final-Osteology Med-Jj [Compatibility Mode]

Documents