Foramina And Canals Of Cranial Base

Front 1

foramen cecum

Back 1

emissary vein to superior sagittal sinus

Front 2

nasal slit & anterior ethmoidal foramen

Back 2

anterior ethmoidal artery, vein, and nerve

Front 3

foramina of cribriform plate

Back 3

olfactory nerves

Front 4

posterior ethmoidal foramen

Back 4

posterior ethmoidal artery, vein, and nerve

Front 5

optic canal (2)

Back 5

1. optic nerve (II)
2. opthalmic artery

Front 6

superior orbital fissure (5)

Back 6

1. oculomotor nerve (III)
2. trochlear nerve (IV)
3. lacrimal, frontal, and nasociliary branches of opthalmic nerve (V1)
4. abducent nerve (VI)
5. superior opthalmic vein

Front 7

foramen rotundum

Back 7

maxillary nerve (V2)

Front 8

foramen ovale (3)

Back 8

1. mandibular nerve (V3)
2. accessory meningeal artery
3. lesser petrosal nerve

Front 9

foramen spinosum (2)

Back 9

1. middle meningeal artery and vein
2. meningeal branch of mandibular nerve

Front 10

foramen lacerum

Back 10

greater petrosal nerve

Front 11

carotid canal (2)

Back 11

1. internal carotid artery
2. internal carotid nerve plexus

Front 12

internal acoustic meatus (3)

Back 12

1. facial nerve (VII)
2. vestibulocochlear nerve (VIII)
3. labyrinthine artery

Front 13

opening of vestibular aqueduct

Back 13

endolymphatic duct

Front 14

mastoid foramen

Back 14

emissary vein (and occasional branch of occipital artery)

Front 15

jugular foramen (6)

Back 15

1. inferior petrosal sinus
2. glossopharyngeal nerve (XI)
3. vagus nerve (X)
4. spinal accessory nerve (XI)
5. sigmoid sinus
6. posterior meningeal artery

Front 16

condylar canal

Back 16

emissary vein and meningeal branch of ascending pharyngeal artery

Front 17

hypoglossal canal

Back 17

hypoglossal nerve (XII)

Front 18

foramen magnum (5)

Back 18

1. medulla oblongata
2. meninges
3. vertebral arteries and venous plexus
4. meningeal branches of vertebral arteries
5. spinal roots of accessory nerves

Front 19

incisive fossa (2)

Back 19

1. nasopalatine nerve
2. sphenopalatine nerve

Front 20

greater palatine foramen

Back 20

greater palatine nerve and vessels

Front 21

lesser palatine foramen

Back 21

lesser palatine nerve and vessels

Front 22

petrotympanic fissure

Back 22

chorda tympani of facial nerve (VII)

Front 23

tympanic canaliculus

Back 23

tympanic branch of glossopharyngeal nerve (IX)

Front 24

mastoid canaliculus

Back 24

auricular branch of vagus nerve (X)

Front 25

stylomastoid foramen

Back 25

facial nerve (VII)

Front 26

jugular fossa (4)

Back 26

1. glossopharyngeal nerve (IX)
2. vagus nerve (X)
3. spinal accessory nerve (XI)
4. superior bulb of internal jugular vein (a dilatation at the beginning of the internal jugular vein)