Posterior Cranial Fossa Flashcards Preview

Spinal Anatomy I - Exam 3 > Posterior Cranial Fossa > Flashcards

Flashcards in Posterior Cranial Fossa Deck (30)
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1
Q

What is the anterior boundary for the posterior cranial fossa?

A
  • posterior clinoid processes (sphenoid)
  • dorsum sella (sphenoid)
  • apex of the petrous portion of the temporal bone
2
Q

What is the posterior boundary for the posterior cranial fossa?

A

squamous part of the occipital bone

3
Q

What forms the roof of the posterior cranial fossa?

A

tentorium cerebelli

4
Q

What part of the cerebrum occupies the posterior cranial fossa?

A

none: the tentorium cerebelli separates the cerebrum into a space above the posterior cranial fossa

5
Q

What part of the cranial nerve system occupies the posterior cranial fossa?

A
  • cerebellum
  • pons
  • medulla oblongata
6
Q

What bony feature is prominent in the median plane of the posterior cranial fossa?

A

the clivus or basilar part of the occipital bone

7
Q

Which cranial nerves exit posterior cranial fossa ostia?

A
  • VII (facial)
  • VIII (vestibulocochlear/auditory)
  • IX (glossopharyngeal)
  • X (vagus)
  • XI (spinal accessory)
  • XII (hypoglossal)
8
Q

Which ostia will allow exit from the posterior cranial fossa?

A
  • foramen magnum
  • internal acoustic meatus
  • jugular foramen
  • hypoglossal canal
  • condylar canal
9
Q

Which single opening will allow the exit of the greatest number of cranial nerves from the posterior cranial fossa?

A

jugular foramen

10
Q

What feature is unique to the foramen magnum?

A

it is the largest unpaired foramen of the skull

11
Q

What will the foramen magnum communicate with?

A
  • posterior cranial fossa

- spinal canal

12
Q

What part of the central nervous system is traditionally said to be present in the foramen magnum?

A

the junction between the brain and spinal cord

13
Q

What are the contents of the foramen magnum?

A
  • medulla oblongata
  • spinal roots of the spinal accessory nerve
  • meningeal branches from the C1-C3 spinal nerves
  • the vertebral arteries
  • anterior and posterior spinal arteries and veins
  • meningeal coverings of the CNS
14
Q

Which arteries arise in the posterior cranial fossa and descend through the foramen magnum to supply the spinal cord?

A

anterior and posterior spinal arteries

15
Q

Which arteries ascend through the foramen magnum to supply the brain?

A

vertebral arteries

16
Q

What will the internal acoustic meatus communicate with?

A
  • posterior cranial fossa

- facial canal of the temporal bone

17
Q

What are the contents of the internal acoustic meatus?

A
  • cranial nerve VII (facial nerve)
  • cranial nerve VIII (vestibulocochlear/auditory nerve)
  • the nervus intermedius/nerve of Wrisberg/sensory root of VII
  • motor root of VII
  • the vestibular and cochlear roots of VIII
  • internal auditory/internal labyrinthine artery and vein
18
Q

Which ostium exiting the cranial fossae will not also exit the skull?

A

internal acoustic meatus

19
Q

What will the jugular foramen communicate with?

A
  • posterior cranial fossa

- neck

20
Q

What bones converge to form the jugular foramen?

A
  • temporal

- occipital

21
Q

What are the contents of the jugular foramen?

A
  • jugular bulb
  • inferior petrosal sinus
  • tympanic/jugular body/glomus
  • cranial nerve IX (glossopharyngeal nerve)
  • cranial nerve X (vagus)
  • cranial nerve XI (spinal accessory)
22
Q

What is the jugular bulb?

A

the venous expansion between the sigmoid dural venous sinus and the internal jugular vein

23
Q

What is the jugular/tympanic body/glomus?

A

a chemoreceptive organ located in the wall of the jugular bulb

24
Q

What is the function of the jugular/tympanic body/glomus?

A

a chemoreceptive organ that monitors hypoxia, hypercapnia, and increases in the hydrogen ion

25
Q

What bone forms the hypoglossal canal?

A

occipital bone

26
Q

What will the hypoglossal canal communicate with?

A
  • posterior cranial fossa

- neck

27
Q

What are the contents of the hypoglossal canal?

A

cranial nerve XII (hypoglossal)

28
Q

What bone forms the condylar canal?

A

occipital bone

29
Q

What will the condylar canal communicate with?

A
  • posterior cranial fossa

- neck

30
Q

What are the contents of the condylar canal?

A

an emissary vein connecting the sigmoid dural venous sinus and the vertebral venous plexus

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