Week 05 - Osteology (Skull).ppt mbbs first year head and neck neuroanatomy

Ppt on skull

1. Theskullisaheadpartoftheskeleton.
Itismadeupofanumberoffusedflatbones.
Itprovidesaprotectivecavityforthebrain
(cranialcavity)
Italsohousessomeorganssuchaseyes,ears,
noseandmouth
Ithasadefensivefunctionbywayofthehorns
Itcontainsmanyforamina,processusand
smallcavities(sinuses)fortheprotection,
defensiveandsupportingfunction.
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2. Theskullisformedbyseveralarticulatedflat
bones
Thetypesofthejointsbetweenthebonesare
stationarysutura(exceptmandibleandhyoid
bone)
Someofthebones(pneumaticbones)alsohave
anaircavity(sinus)forsomevitalfunctions
NEUROCRANIUM
VISCEROCRANIUM
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3. Theskulliscomposedoftwoparts;
NEUROCRANIUM VISCEROCRANIUM
(formsthecranialcavity) (supportstheface)
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-OS OCCIPITALE
-OS INTERPARIETALE
-OS PARIETALE
-OS FRONTALE
-OS ETHMOIDALE
-OS SPHENOIDALE
-OS TEMPORALE
-OS PTERYGOIDEUM
-VOMER
-OS NASALE
-OS ROSTRALE
-OS LACRIMALE
-OS ZYGOMATICUM
-OS MAXILLARE
-OS INCISIVUM
-OS PALATINUM
-MANDIBULA
-OS HYOIDEUM

4. Itformsthemarginsofthecranialcavityoftheskullwhichhousesbrain.Ithasaroof,
afloor,andwalls(laterl,nasal,nuchal)likeabox
Osoccipitale
Osinterparietale
Osparietale
Osfrontale
Osethmoidale
Ossphenoidale
Ostemporale
Ospterygoideum
vomer
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NEUROCRANIUM

5. It is located on the nuchal wall of the skull. It encloses the
foramen magnum which links the brain and spinal cord.
PARS BASILARIS
Synchondrosis sphenooccipitalis
Foramen lacerum (eq, su)
Foramen jugulare (Car, ru)
PARS LATERALIS
Condylus occipitalis
Processus jugularis
Canalis ni hypoglossi
SQUAMA OCCIPITALIS
Crista nuchae (Car, eq, su) –Linea nuchae (ru)
Protuberantia occipitalis externa (absent in Su)
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OS OCCIPITALE

6. It is located on the nuchal wall of the skull. It
encloses the foramen magnum which links the
brain and spinal cord.
PARS BASILARIS
Synchondrosis sphenooccipitalis
Foramen lacerum (eq, su)
Foramen jugulare (Car, ru)
PARS LATERALIS
Condylus occipitalis
Processus jugularis
Canalis ni hypoglossi
SQUAMA OCCIPITALIS
Crista nuchae (Car, eq, su) –Linea nuchae (ru)
Protuberantia occipitalis externa (absent in Su)
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OS OCCIPITALE

7. It fuses with the parietal and occipal bones in adult
Processus tentoricus (Car, eq)
Tenterium cerebelli osseum
Tenterium cerebelli membranaceum
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OS INTERPARIETALE

8. Tuber parietale
Crista sagittalis externa (eq ve car)
Planum nuchale (bo)
Planum parietale (ov, cap, su)
Planum temporale
Linea temporalis
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OS PARIETALE

9. Cot
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OS FRONTALE
SQUAMA FRONTALIS
proc. cornualis (ru)
protuberantia intercornualis (ru)
proc.zygomaticus
arcus orbitae
lig.orbitale (Car, su)
for.supraorbitale (Car’da yok)
Sulcus supraorbitalis (ru)
fossa glandulae lacrimalis
PARS ORBITALIS
PARS NASALIS

10. It resembles a horizontally placed tube.
Lamina perpendicularis
crista galli
Lamina cribrosa
fossa ethmoidalis
Lamina tectoria
Lamina basalis
Lamina orbitalis
Ethmoturbinalia
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OS ETHMOIDALE

11. OS TEMPORALE
The temporal bone is composed of squamous, petrosal and tympanic parts and
forms the lateral wall of the cranial cavity.
It articulates with the mandible (art.temporomandibularis).
It consists of three parts; Pars squamosa, Pars petrosa, Pars tympanica
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12. Pars Squamosa
It has a cup-like basal part which is involved in the
formation of the lateral wall of the cranial cavity.
Facies cerebralis
Facies temporalis
Linea temporalis
Fossa temporalis
Proc.zygomaticus
Fossa mandibulae
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13. Pars Tympanica
It is the retroventral part lying at the base of the skull.
Porus acusticus externus
Meatus acusticus externus
Bulla tympanica
(Absent in man
Oval-shaped in eq and ov,
Spere-shaped in Car,
Well-developed in bo and su)
Cavum tympani
***middle ear
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14. Pars Petrosa
It is the caudoventral part of the temporal bone.It locates at the inner surface.
Porus acusticus internus
Meatus acusticus internus
Proc.mastoideus (absent in su)
Proc.styloideus (Ru, eq)
***hyoid bone attaches***
For.stylomastoideum (Canalis facialis)
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15. It is an unpaired bone which forms the rostral part of the
base of the cranial cavity. The shape of the bone like a
wedge and it consists of two fused parts that are united
synchondrosis intersphenoidalis at birth.
OS PRESPHENOIDALE
Ala orbitalis
Corpus
OS BASISPHENOIDALE
Ala temporalis
Corpus
Proc.pterygoideus
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OS SPHENOIDALE

16. OS PRESPHENOIDALE
Ala orbitalis
crista orbitasphenoidale
Corpus
canalis opticus
OS BASISPHENOIDALE
Ala temporalis
for.lacerum
(for.caroticum; Car)
(for.ovale; Car, ru)
Corpus
fossa hypophysialis
dorsum sellae
sella turcica
Proc.pterygoideus
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OS SPHENOIDALE

17. Cot
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OS SPHENOIDALE
***Cristaorbitasphenoidale
for.ethmoidale
(Car; forr.ethmoidalia)
for.opticum
fissuraorbitalis(Car, eq)
for.rotundum (Car, eq)
for.orbitorotundum(Ru, su)
for.alareorale(rostrale) (Car, eq)
for.alareaborale(caudale) (Car, eq)
canalisalaris
for.alareparvum(eq)

18. OS PTERYGOIDEUM
It is a small paired bones at the base of the skull. It contrubutes the forming of the
lateral wall of the choana. It takes the form of a flat bone which is situated between
pterygoid process of sphenoid and perpendicular lamina of palatine bones
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19. OS VOMER
It is a long unpaired bone that extends the nasal cavity
sulcus vomeris
ala vomeris
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20. Thebonesofthefacesurroundthenasal
andoralcavity.Facialbonescanshow
greatvarietyinshapeamongspecies
(evenifwithinspeciesespeciallyindogs).
osnasale
osrostrale
oslacrımale
oszygomatıcum
osmaxıllare
osıncısıvum
ospalatınum
mandıbula
oshyoıdeum
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VISCEROCRANIUM

21. It forms the roof of the nasal cavity.
It is situated rostral to the frontal bone
Inc.nasoincisiva (eq, su, bo) (absent in car)
Inc.nasomaxillaris (ov)
Processus nasalis : tapered rostral end
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OS NASALE
Eq, ov, suBo, capcar

22. It forms the rostral wall of the orbit.
Facies facialis
Fossa lacrimalis externa (su, ov)
Facies orbitalis
Fossa sacci lacrimalis (absent in su)
Foramen lacrimale
Foramina lacrimalia (su)
Canalis lacrimalis
Bulla lacrimalis (well-developed in ox)
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OS LACRIMALE

23. Arcus zygomaticus : is formed by proc.temporalis of zygomatic bone and
proc.zygomaticus of temporal bone
Processus temporalis and Processus frontalis (ru)
Crista facialis («S» shaped in ru)
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OS ZYGOMATICUM

24. Upper jaw bone is the largest bone of the skull.
Corpus maxilla
Processus alveolaris is a longitudinal ridge projects ventrally
Processus palatinus is a horizontal plate-like part that forms
the basis of the hard palate.
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OS MAXILLA –Upper jaw

25. Crista facialis
Tuber faciale (rum)
For.infraorbitale
Canalis infraorbitalis
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OS MAXILLA
The Body

26. Juga alveolariais ridges formed by the roots of cheek teeth
Margo alveolaris is free border of the bone for alveols of teeth
Margo interalveolarisis a space without teeth
Tuber maxillais caudal enlarged part of the bone
Fossa pterygopalatina
I-For. maxillare
II-For. sphenopalatinum
III-For. palatinum aborale
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OS MAXILLA
Alveolar process

27. It forms both the floor of the nasal cavity and the roof of the oral cavity.
Caudally; it fuses with the palatine bone and in front; it forms the palatine fissure
Sutura palatina
For. palatinum majus
Canalis palatinus
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OS MAXILLA
Palatine process

28. It forms the apex of the skull and participates in forming the hard palate.
Corpus ossis incisivi
 Foramen incisivum (eq, car)
 Fissura incisiva (ru, su)
Processus palatinus
 Fissura palatina
Processus nasalis
 Inc. nasoincisiva
Processus alveolaris
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OS INCISIVUM

29. It is situated behind the maxilla.
Lamina horizontalis contrubutes to the formation of the hard palate
Lamina perpendicularis margins the lateral wall of the choana
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OS PALATINUM

30. Mandible is the lowest part of the skull. It holds the lower teeth and attaches the
cranium with a movable joint (art.temporomandibularis)
The left and right bones are formed a rostral line (synchondrosis intermandibularis)
by the fusion during mandibular development after birth
Spatium mandibulare is a space between two bones. The tongue fills the space in
living animals
* CORPUS MANDIBULAE
* RAMUS MANDIBULAE
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MANDIBULA
The Lower jaw bone

31. Facies labialis
Facies buccalis
Facies lingualis
Margo ventralis
Margo alveolaris
Alveoli dentales
Margo interalveolaris
Foramen mentale
Foramina mentalia (car, su)
Inc. vasorum facialium
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MANDIBULA
The Body

32. Processus muscularis ( proc.coronoideus )
Processus articularis ( proc.condylaris )
 Caput mandibulae
 Collum mandibulae
Incisura mandibulae
Fossa masseterica (Car)
Foramen mandibulae
Canalis mandibulae
Processus angularis (Car)
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MANDIBULA
The Arm

33. Hyoid bone is a seperate bone from the cranium like mandible. It attaches the styloid
process (mastoid process in car.) of the temporal bone and forms a slightly movable
joint. The bone comprises several rod-shaped elements articulate with each other.
Basihyoideum
Proc. lingualis
Thyrohyoideum
Ceratohyoideum
Epihyoideum
Stylohyoideum
Tympanohyoideum
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OS HYOIDEUM