Bones: Skull connections and special cavities Flashcards
Foramen rotundum connects what to what?
Middle cranial fossa to pterrygopalatine fossa
Cribriform plate connects what to what?
Anterior cranial fossa to the nasal cavity
Anterior ethmoidal foramen connects what to what?
Connects the anterior cranial fossa to the ethmoidal air cells and orbit
Foramen ovale connects what to what?
Connects the middle cranial fossa to infratemporal fossa
Foramen spinosum connects what to what?
Middle cranial cavity to infratemporal fossa
Carotid canal connects what to what?
The middle cranial fossa to the external base of skull
Foramen lacerum connects what to what?
Middle cranial fossa to the external skull base
Sphenopetrosal fissure connects what to what?
Middle cranial fossa to the external skull base
Hiatus/canal for the greater petrosal nerve connects what to what?
Middle cranial fossa to facial canal
- g.p. nerve arises from facial nerve at geniculate ganglion
The canal and hiatus for the lesser petrosal nerve connect what to what?
Tympanic cavity to middle cranial fossa
- l. p. nerve then courses forward and exits via foramen ovale to infratemporal fossa
Foramen magnum connects what to what?
The posterior cranial fossa to the Vertebral canal and spinal cord
Internal acoustic meatus connects what to what?
posterior cranial fossa to the facial canal
Jugular foramen connects what to what?
Posterior cranial fossa to the external skull base
Hypoglossal canal connects what to what?
Posterior cranial fossa to the external surface
The optic canal connects what to what?
orbital cavity to the middle cranial fossa
The superior orbital fissure connects what to what?
The orbit to the middle cranial fossa
The inferior orbital fissure connects what to what?
The orbit to the pterygopalatine fossa
The posterior ethmoidal foramen connects what to what?
anterior cranial fossa to the posterior ethmoidal air cells to orbit
The nasolacrimal canal connects what to what?
Orbit to the inferior nasal meatus
infraorbital canal connects what to what?
orbit to the canine fossa
- starts in the orbit at the infraorbital groove and transcends the maxilla, ending on the anterior surface of maxilla at the infraorbital foramen
The supraorbital foramen connects what to what?
the orbit to the frontal region
Frontal notch connects what to what?
Orbit to the frontal region
Zygomaticotemporal foramen connects what to what?
The orbit (via the zygomatico-orbit foramen) to the temporal surface of the zygomatic bone
Zygomaticofacial foramen connects what to what?
The orbit (via the zygomatico-orbit foramen) to the lateral surface of the face
Sphenopalatine foramen connects what to what?
pterygopalatine fossa to the nasal cavity (COMMON nasal meatus)
Incisive foramen connects what to what?
The nasal cavity to the oral cavity
The lesser and greater palatine foramen connects what to what?
The pterygopalatine fossa to the posterior oral cavity
The sphenoid/greater wing has how many surfaces/facets? What are their names?
5 Facets or Surfaces
- Cerebral
- Infratemporal
- Temporal
- Orbital
- Pterygomaxillar or Anterior
External acoustic meatus connects what to what?
tympanic region of the temporal bone to the tympanic membrane
Cochlear canaliculus
external skull base to the inner ear
- tiny, practically invisible opening medial to carotid canal and anterior to jugular fossa
Stylomastoid foramen
External base of skull to facial canal and eventually out internal acoustic meatus to posterior cranial fossa
Choana connects what to what?
the opening between the nasal cavity and the nasopharynx.
Foramen caecum connects what to what?
Nowhere. It is a blind foramen
Musculotubal canal connects what to what?
What are its two divisions?
External skull base to tympanic cavity
- divided into semicanal for tensor tympani and semicanal for eustachian tube
- begins near apex of petrous portion of the temporal bone and runs posterolaterally to tympanic cavity
Describe the route of the facial canal from inside to outside the skull.
know the cross section of the internal acoustic meatus
Include any significant branches off the facial canal to other exits.
- Begins in the posterior cranial fossa at the anterior superior opening of the internal acoustic meatus
- Briefly runs perpendicular to the axis of the petrous part of the temporal bone
- After bending at the geniculum, runs posterolaterally parallel to axis of the petrous part
- Finally courses inferiorly out the stylomastoid foramen to the external base of the skull
- includes a small branch off the final inferiorly-coursing part containing the chorda tympani which exits from the petrotympanic (Glaserian) fissure
What are the 6 connections of the pterygopalatine fossa?
Where do they go?
- foramen rotundum (scala media)
- **pterygoid canal **(ext. base of skull)
- **sphenopalatine foramen **(nasal cavity)
- **inferior orbital fissure **(orbit)
- **greater and lesser palatine foramen **(oral cavity)
- **pterygomaxillary fissure **(lateral surface of skull)
What are the 5 connections to the infratemporal fossa?
Where do they go?
- **inferior orbital fissure **(orbit)
- **foramen ovale **(scala media)
- **foramen spinosum **(scala media)
- **pterygomaxillary fissure **(pterygopalatine fossa)
- **petrotympanic fissure **(facial canal)
What are the 6 connections of the posterior scala?
Where do they go?
- **foramen magnum **(ext. base)
- **jugular foramen **(ext. base)
- **hypoglossal canal **(ext. base)
- **internal acoustic meatus **(stylomastoid foramen via facial canal)
- **vestibular aqueduct **(tympanic cavity)
- **mastoid foramen **(ext. base, post. to mastoid process)
What is the area where most of the sinuses empty into the nasal cavity?
What three sets of sinus connect there?
Semilunar Hiatus
- beneath middle nasal concha just inferior to ethmoid bulla
- **maxillary **(empties into posterior)
- anterior ethmoid sinus (empties into center)
- **frontal sinus **(empties anteriorly via infundible or frontonasal duct)
For the 5… what structures can narrow the semilunar hiatus and hamper sinus flow?
- ethmoidal bulla
- uncinate process
Which sinus empties into somewhere other than the semilunar hiatus? And where does it empty?
Sphenoid Sinus empties into the sphenoethmoidal recess at the top of the common nasal meatus
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What is it? Where is it? What emptes into it?
Sphenoethmoidal Recess
- at top of common nasal meatus
- sphenoid sinus empties into it
What are the four sets of paranasal sinuses?
- Maxillary
- Frontal
- Sphenoid
- Ethmoid Air Cells
What is the “base” of the orbit and the “apex”?
the aditus orbitae (anterior opening) is the base
the optic canal is the apex
the tympanic canalcus is located where and connects what to what?
it connects from the inferior surface of the petrous portion to the floor of the tympanic cavity.
Located in the wedge of bone separating the jugular canal and carotid canal, it transmits the tympanic branch of the glossopharyngeal nerve.
the mastoid canaliculus is where?
and connects what to what?
- extends from the lateral portion of the jugular fossa **laterally through the mastoid process to the tympano-mastoid fissure.
- transmits the auricular branch of the vagus
the musculotubarius canal is where and connects what to what?
what are its two parts?
external base of the skull to the tympanic cavity/inner ear
divided by a septum into two semi-canals:
- Semicanal for the pharyngotympanic (Eustachian or auditory) tube
- Semicanal for the tensor tympani muscle
the nasolacrimal canal connects what to what?
orbit to the nasal cavity
ethmoidal infundibulum connects what to what? is located where?
connects the frontal nasal sinus to the middle nasal meatus, under the middle nasal concha.
the opening to the infundibulum is the most anterior and superior part of the semilunar hiatus
the chorda tympani connects what to what?
branches off of the facial canal near the tympanic cavity, transends the tympanic cavity, and exits through the petrotympanic fissure
stapedius canaliculus connects what to what?
goes from the tympanic cavity to the facial canal
supraorbital foramen, where to where
orbit to the forehead/supraorbital region of the frontal bone
the condylar canal, where to where?
posterior cranial fossa to the external base of the skull
what is the basic cross section of the internal acoustic meatus?
Superior-anterior: facial canal
Other portion: the vestibular-cochlear canal
(shown below as the right internal acoustic meatus)
What are the 9 connections of the orbit?
Where do they go?
- optic canal (m. cranial fossa)
- sup. orbital fissure (m. cranial fossa)
- inf. orbital fissure (infratemp. fossa and pterygopal. fossa)
- ant. ethmoid foramen (ethmoid air cells + ant. cranial fossa via cranioorbital foramen)
- post. ethmoid foramen (ethmoid air cells)
- infraorbital canal (infraorbital foramen/face/canine fossa)
- nasolacrimal canal (inferior nasal meatus)
- supraorbital foramen/frontal notch (forehead)
- zygomatico-orbital foramen (z-facial and z-temporal foramina)
What are the superior, anterior, posterior, medial and lateral walls/borders of the pterygopalatine fossa?
- Anterior - maxilla/maxillary tuberosity
- Posterior - pterygoid processes
- Medial - perpendicular process of palatine
- Lateral - pterygomaxillary fissure
- Superior - body/greater wing of sphenoid
