30: Skull Foramina and Cranial Nerves

fissure

opening between 2 bones (articulation)

foramen

hole within a bone

canal

elongated passageway, has its own foramen on each end

meatus

air filled passageways

What is the name of cranial n. III, and what innervation is it?

oculomotor n.

GSE and GVE

GSE

general somatic efferent (motor)

GSA

general somatic afferent (sensory)

GVE

general visceral efferent (parasympathetic)

What is the name of cranial n. IV, and what innervation is it?

trochlear n. 

GSE

What is the name of cranial n. VI, and what innervation is it?

abducens n.

GSE

What is the name of cranial n. II, and what innervation is it?

optic n.

special afferent

What is the name of cranial n. I, and what innervation is it?

olfactory n.

special afferent

What is the name of cranial n. VII, and what innervation is it?

facial n.

GSE, GSA, GVE, special afferent

What is the name of cranial n. IX, and what innervation is it?

glossopharyngeal n.

GSA, GSE, GVE, special afferent

What is the name of cranial n. V, and what innervation is it?

trigeminal n.

GSA

What is the name of cranial n. VIII, and what innervation is it?

vestibulocochlear n.

special afferent

What is the name of cranial n. X, and what innervation is it?

vagus n.

GVE, GSE, GSA, special afferent

What is the name of cranial n. XI, and what innervation is it?

accessory n.

GSE

What is the name of cranial n. XII, and what innervation is it?

hypoglossal n.

GSE

The trigeminal nerve has 3 branches. What are they, and what is their innervation?

V1- GSA

V2- GSA

V3- GSA and GSE

Why is it important to know the skull and mandible foramen?

nerve blocks

The foramen magnum is the passageway for what structures?

spinal cord

meninges

vessels

The muscular tubercles are located between what structures? What is their function?

basilar portion of occipital bone and basisphenoid bone

point of insertion of the longus capitis mm.

The vertebral arteries converge in the skull to form what structure? Where?

basilar a.

basilar part of occipital bone

The hypoglossal canal is the passageway for what nerve? What does this nerve innervate?

CN XII (hypoglossal n.)

motor to the tongue

The tympana-occipital fissure is a passageway for what structure(s)? 

CN IX (glossopharyngeal n.)

CN X (vagus n.)

CN XI (accessory n.)

internal carotid a.

sympathetic nn. 

What attaches to the tentorial process? Where isthmus process located?

dura matter attaches and extends down between cerebellum and cerebrum

between the brain hemispheres and cerebellum

The zygomatic process is a process of what bone? What bone does it articulate, and what structure does it form?

temporal bone

zygomatic bone

zygomatic arch

What 2 structures form the bony processes of the temporomandibular joint?

mandibular fossa and condylar process

What fossa conjoins with the condylar process of the mandible? 

mandibular fossa

The mandibular process is the site of articulation with what bone? What joint does this form?

condylar process of the mandible

temporomandibular joint

The internal petrosal portion of the temporal bone provides what canal, meatus, fossa, and foramen?

canal for trigeminal n. (CN V)

internal acoustic meatus

cerebellar fossa

jugular foramen

The apex of the petrosal portion of the temporal bone is directed in what direction?

rostrally

The internal acoustic meatus houses what structures?

facial n. (CV VII)

vestibulocochlear n. (CN VIII)

The cerebellar fossa houses what structure?

parafollicular lobe of cerebellum

The jugular foramen houses what structures?

CN IX, X, and XI

The external petrosal portion of the temporal bone has what process and foramen?

mastoid process

stylomastoid foramen

What is the significance of the mastoid process?

point of insertion of some neck muscles

What structures pass through the stylomastoid foramen?

facial n. (CN VII)

The tympanic portion of the temporal bone is contains a bulla, meatus, and foramen. What are they?

tympanic bulla

external acoustic meatus

retroarticular foramen

The retroarticular foramen provides passage for what structure?

retroarticular vein

tympanic bulla

hemispherical bony structure, encapsulates air-filled, ventral expansion of middle ear cavity 

The external acoustic meatus leads into what area? What is this structure?

cavity of the middle ear

short, bony canal where the tympanic membrane attaches

What structure serves as the landmark between the middle and external ear?

external acoustic meatus

The basisphenoid bone contains a fissure, 4 foramen, a fossa, and a tiny prominence. What are they?

orbital fissure

round, oval, caudal alar, and rostral alar foramen

hypophyseal fossa

dorsum sellae

The orbital fissure allows passage of what structures?

oculomotor n. (CN III)

trochlear n. (CN IV)

abducens n. (CN VI)

ophthalmic n. (CN V-1)

The trigeminal nerve has 3 branches. What are they?

ophthalmic n. (CN V-1)

maxillary n. (CN V-2)

mandibular n. (CN V-3)

The round foramen allows passage of what structure?

maxillary n. (CN V-2)

The oval foramen allows passage of what structure?

mandibular n. (CN V-3)

The hypophyseal fossa houses what structure? In what depression is it located?

hypophysis (pituitary gland)

sella turcica

What is the name of the caudal-most bony prominence of the sella turcica?

dorsum sellae

The caudal alar foramen allows passage for what structure?

maxillary a.

The rostral alar foramen allows passage for what structures?

maxillary n.

maxillary a.

The alar canal is located between what two foramen?

caudal alar and rostral alar foramen

The presphenoid bone contains what structures?

optic canals

chiasmatic groove

The optic canals allow passage of what structure?

optic n. (CN II)

chiasmatic groove

bony groove for optic chiasm

corresponds to the optic nn. crossover

What structure forms the rostral part of the temporal fossa?

temporal surface/face

What structure forms the medial surface of the orbit?

orbital part of the frontal bone

The frontal bone is what type of bone? What does this mean?

pneumatic bone

it contains air filled spaces or sinuses connected with the nasal cavity

How many sinuses are there normally in the frontal bone? The cavity of some of these (particularly the most rostral) are occupied by what?

3

ectoturbinate bone structures (part of ethmoid bone)

ectoturbinate

bony formations from the ethmoidal bone located in the most rostral areas of the frontal sinus

What structures make up the nasal septum?

perpendicular plate of the ethmoid bone

nasal septum cartilage

vomer

The vomer articulates with what structures?

perpendicular plate of the ethmoid bone

nasal septum cartilage

cribriform plate

bony wall between the cranial and nasal cavities

The cribriform plate allows passage of what structures?

olfactory nn. (CN I)

vomeronasal nn.

The lacrimal bone contains what fossa?

fossa for the lacrimal sac

The maxilla contains 2 foramen with a canal in-between, as well as a fossa and two more foramen. What are their names?

infraorbital foramen

maxillary foramen

infraorbital canal

pterygopalatine fossa

sphenopalatine foramen

caudal palatine foramen

The infraorbital canal is located between what two foramen?

infraorbital foramen

maxillary foramen

The infraorbital foramen allows passage of what structures?

branches of the maxillary n. (CN V-2)

The maxillary foramen allows passage of what structures? In what view can it not be seen?

maxillary n. (CN V-2)

lateral

Where can the infraorbital foramen be accessed?

through buccal vestibule, at level of 3rd and 4th superior premolars

sphenopalatine foramen

communication between the pterygopalatine fossa and nasal cavity

vessels and nerves toward nasal conchae and its mucosa

caudal palatine foramen

communication between pterygopalatine fossa and hard palate

vessels and nerves toward hard palate bones and mucosa

Both the sphenopalatine and caudal palatine foramen allow passage of what structures?

branches of maxillary n. (CN V-2)

The palatine portion of the maxilla contains a process and two foramen. What are they?

palatine process of maxilla

major palatine foramen

minor palatine foramen

The major palatine foramen allows passage for what structures?

branch of maxillary n. (CN V-2)

vessels and nerves toward the hard palate mucosa

The minor palatine foramen allows passage for what structures? Where is it normally located?

branch of maxillary n. (CN V-2)

vessels and nerves toward rheumatoid arthritis hard palate mucosa

between maxilla and palatine bones

The palatine bone contains one foramen and 2 laminate. What are their names?

minor palatine foramen

horizontal laminate of palatine bone

perpendicular laminate of palatine bone

The mandible contains a canal in between 2 foramen. What are their names?

mandibular canal

mandibular foramen

mental foramina

The mandibular foramen is the caudal opening of what canal? What passes through here?

mandibular canal

branch of mandibular n. (CN V-3)

The mental foramina is the rostral opening of what canal? What passes through here?

mandibular canal

branches of mandibular n. (CN V-3)

Name the structure(s) indicated by a and b. 

zygomatic process

zygomatic arch

Name the structure(s) indicated by a. 

mandibular fossa

Name the structure(s) indicated by a and b.

mastoid process

stylomastoid foramen

Name the structure(s) indicated by a, b, c, and d.

retroarticular process

retroarticular foramen

tympanic bulla

external acoustic meatus

Name the structure(s) indicated by a, b, and c. 

stylomastoid foramen

facial n. 

entrance into tympanic cavity

Name the structure(s) indicated by d, e, and f.

retroarticular foramen

retroarticular v.

tympanic bulla

Name the structure(s) indicated by a and b. 

external acoustic meatus

tympanic bulla

Name the structure(s) indicated by a, b, and c. 

sphenoid bone

presphenoid

basisphenoid

Name the structure(s) indicated by a, b, and c.

orbital fissure

round foramen

oval foramen

Name the structure(s) indicated by d and e.

hypophyseal fossa

dorsum sellae

Name the structure(s) indicated by a and b.

dorsum sellae

hypophyseal fossa

Name the structure(s) indicated by a, b and c.

orbital fissure

mandibular fossa

oval foramen

Name the structure(s) indicated by d, e, and f.

caudal alar foramen

rostral alar foramen

alar canal

Name the structure(s) indicated by a, b, and c.

ethmoidal labyrinth (ethmoturbinates bones)

perpendicular plate

cribriform plate

Name the structure(s) indicated by a, b, and c.

palatine process of maxilla

major palatine foramen

minor palatine foramen

Name the structure(s) indicated by a, b, and c.

messeteric fossa

mandibular foramen

mental foramina

Name the structure(s) indicated by a, b, and c.

foramen magnum

basilar part of occipital bone

muscular tubercles

Name the structure(s) indicated by a, b, and c.

hypoglossal canal

jugular process

tympana-occipital fissure