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Caudodorsal view

(without calvaria)

Caudal view

Internal view

(halved skull)

Lateral view

Ventral view

Ventral view

(enlarged)

Th

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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

foramen jugulare between os temporale and os occipitale

n. glossopharyngeus (IX.)

n. vagus (X.)

n. accessorius (XI.)

fissura petrooccipitalis between os temporale and os occipitalis pars basilaris eq, su, bo

foramen lacerum

▪ incisura carotica

▪ incisura ovalis

▪ incisura spinosa

between os basisphenoidale, os temporale and os occipitale eq, su

medial notch of foramen lacerum - in horse it’s doubled

eq, su

middle notch of foramen lacerum n. mandibularis (V/3.)

eq, su

lateral notch of foramen lacerum ramus meningeus of n. mandibularis (V/3.)

eq, su

foramen caroticum rostral to bulla tympani, medially ca

foramen ovale rostral to bulla tympani, laterally n. mandibularis (V/3.)

ca, bo

foramen spinosum rostral to bulla tympani, next to for. ovale - often fuses with the for. ovale

ca

meatus acusticus externus external auditory channel

meatus temporalis between os temporale and os parietale eq, ca, bo

foramen stylomastoideum outer opening of facial channel (canalis facialis),

caudoventral to the porus acusticus externus n. facialis (VII.)

foramen retroarticulare outer opening of meatus temporalis,

rostral to the porus acusticus externus - in ox it could have 2-3 openings

foramen mastoideum on squama occipitalis, dorsal to for. magnum eq, ca, bo

canalis musculotubarius

below temporal bone’s processus muscularis,

it’s divided by a septum into:

- semicanalis tubae auditivae Eustachii

- semicanalis m. tensor veli palatini

for Eustachian (auditory) tube

canaliculus chorda tympani from canalis facialis into tympanic cavity chorda tympani from n. facialis (VII.)

foramen ethmoidale opens on os frontalen

(in horse between os frontale and os praesphenoidale) - in dogs it’s doubled (foramina ethmoidalia)

foramen opticum a canalis opticus nyílása n. opticus (II.)

fissura orbitalis between os praesphenoidale and os basisphenoidale

n. oculomotorius (III.), n. trochlearis (IV.)

n. ophtalmicus (V/1.), n. abducens (VI.)

eq, ca

foramen rotundum on os basisphenoidalen, opens into canalis alaris n. maxillaris (V/2.)

eq, ca

foramen orbitorotundum between os praesphenoidale and os basisphenoidale

(fusion of fissura orbitalis and foramen rotundum)

n. oculomotorius (III.), n. trochlearis (IV.)

n. ophtalmicus (V/1.), n. abducens (VI.)

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

▪ area n. facialis

(introitus canalis facialis)

▪ area cochleae

▪ area vestibularis dorsalis

▪ area vestibularis ventralis

internal auditory channel a VII. és VIII. agyvelői idegek

leads into canalis facialis n. facialis (VII.)

towards auditory portion of inner ear n. vestibulocochlearis (VIII.)

towards semicircular channels n. vestibulocochlearis (VIII.)

towards semicircular channels n. vestibulocochlearis (VIII.)

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