The equine skull equine The
Caudodorsal view (without calvaria)
Caudal view
Lateral view
Internal view (halved skull) Ventral view
Ventral view (enlarged)
skull
canine
The The
Caudodorsal view
(without calvaria)
Caudal view
Lateral view
(zygomatic arch is partly removed)
Internal view (halved skull)
Ventral view
Main openings of neurocranium Localization Remarks, main nerves foramen magnum caudal opening towards canalis vertebralis medulla oblongata to spinal cord canalis n. hypoglossi opens into fossa condylaris ventralis n. hypoglossus (XII.) canalis condylaris on the inner side of condylus occipitalis ca, bo n. glossopharyngeus (IX.) foramen jugulare between os temporale and os occipitale n. vagus (X.) n. accessorius (XI.) fissura petrooccipitalis between os temporale and os occipitalis pars basilaris eq, su, bo foramen lacerum between os basisphenoidale, os temporale and os occipitale eq, su - in horse it’s doubled medial notch of foramen lacerum ▪ incisura carotica eq, su
▪ incisura ovalis n. mandibularis (V/3.) middle notch of foramen lacerum eq, su ▪ incisura spinosa ramus meningeus of n. mandibularis (V/3.) lateral notch of foramen lacerum eq, su foramen caroticum rostral to bulla tympani, medially ca n. mandibularis (V/3.) foramen ovale rostral to bulla tympani, laterally ca, bo - often fuses with the for. ovale foramen spinosum rostral to bulla tympani, next to for. ovale ca meatus acusticus externus external auditory channel meatus temporalis between os temporale and os parietale eq, ca, bo outer opening of facial channel (canalis facialis), foramen stylomastoideum n. facialis (VII.) caudoventral to the porus acusticus externus outer opening of meatus temporalis, foramen retroarticulare - in ox it could have 2-3 openings rostral to the porus acusticus externus foramen mastoideum on squama occipitalis, dorsal to for. magnum eq, ca, bo below temporal bone’s processus muscularis, it’s divided by a septum into: canalis musculotubarius for Eustachian (auditory) tube - semicanalis tubae auditivae Eustachii - semicanalis m. tensor veli palatini canaliculus chorda tympani from canalis facialis into tympanic cavity chorda tympani from n. facialis (VII.) opens on os frontalen foramen ethmoidale - in dogs it’s doubled (foramina ethmoidalia) (in horse between os frontale and os praesphenoidale) foramen opticum a canalis opticus nyílása n. opticus (II.) n. oculomotorius (III.), n. trochlearis (IV.) fissura orbitalis between os praesphenoidale and os basisphenoidale n. ophtalmicus (V/1.), n. abducens (VI.) eq, ca n. maxillaris (V/2.) foramen rotundum on os basisphenoidalen, opens into canalis alaris eq, ca n. oculomotorius (III.), n. trochlearis (IV.) between os praesphenoidale and os basisphenoidale n. ophtalmicus (V/1.), n. abducens (VI.) foramen orbitorotundum (fusion of fissura orbitalis and foramen rotundum) n. maxillaris (V/2.) bo, su canalis opticus from sulcus chiasmatis to for. opticum n. opticus (II.) canalis alaris through pterygoid process of os basisphenoidale eq, ca foramen alare rostrale rostral opening of canalis alaris eq, ca foramen alare caudale caudal opening of canalis alaris eq, ca foramen alare parvum dorsal opening of canalis alaris, behind for. opticum eq canalis pterygoideus medial to the pterygoid process of os basisphenoidale n. canalis pterygoideus meatus acusticus internus internal auditory channel a VII. és VIII. agyvelői idegek n. facialis (VII.) ▪ area n. facialis leads into canalis facialis
(introitus canalis facialis) n. vestibulocochlearis (VIII.) towards auditory portion of inner ear ▪ area cochleae n. vestibulocochlearis (VIII.) towards semicircular channels ▪ area vestibularis dorsalis n. vestibulocochlearis (VIII.) towards semicircular channels ▪ area vestibularis ventralis apertura externa aqueductus vestibuli opening medial on the petrosal bone for endolymphatic duct apertura externa canaliculi cochleae opening medial on the petrosal bone for periymphatic duct
Cranial nerves
I. N. olfactorius II. N. opticus III. N. oculomotorius IV. N. trochlearis V. N. trigeminus V/1. N. ophtalmicus V/2. N. maxillaris V/3. N. mandibularis VI. N. abducens VII. N. facialis VIII. N. vestibulocochlearis IX. N. glossopharyngeus X. N. vagus XI. N. accessorius XII. N. hypoglossus