Posterior Cranial Fossa Flashcards

Examine the posterior cranial fossa, including its bony boundaries, brainstem and cerebellar relationships, foramina, venous sinuses, and clinical anatomy.

Card 1 of 30Question

What is the posterior cranial fossa?

The deepest and most posterior depression of the internal cranial base.

In This Section

1. What is the posterior cranial fossa?

The deepest and most posterior depression of the internal cranial base.

2. Which bones form the posterior cranial fossa?

Primarily the occipital and temporal bones, with a contribution from the sphenoid bone.

3. Which major brain structures occupy the posterior cranial fossa?

The cerebellum, pons, and medulla oblongata.

4. What forms the anterior boundary of the posterior cranial fossa?

The dorsum sellae and superior borders of the petrous temporal bones.

5. Which bone forms most of the floor and posterior wall of the posterior cranial fossa?

The occipital bone.

6. Which dural fold forms the roof over much of the posterior cranial fossa?

The tentorium cerebelli.

7. What is the tentorial notch?

An anterior opening in the tentorium cerebelli through which the brainstem passes.

8. What is the clivus?

A sloping bony surface formed by the sphenoid body and basilar occipital bone.

9. Which part of the brainstem lies directly against the clivus?

The pons, with the medulla oblongata lying inferiorly.

10. What is the largest opening in the posterior cranial fossa?

The foramen magnum.

11. Which major neural structure passes through the foramen magnum?

The medulla oblongata, continuing inferiorly as the spinal cord.

12. Which arteries pass through the foramen magnum?

The vertebral arteries and anterior and posterior spinal arteries.

13. Which cranial nerve roots enter the cranial cavity through the foramen magnum?

The spinal roots of the accessory nerve (cranial nerve XI).

14. Which cranial nerves enter the internal acoustic meatus?

The facial nerve (VII) and vestibulocochlear nerve (VIII).

15. Which artery accompanies cranial nerves VII and VIII into the internal acoustic meatus?

The labyrinthine artery, usually a branch of the anterior inferior cerebellar artery.

16. Which cranial nerves pass through the jugular foramen?

The glossopharyngeal (IX), vagus (X), and accessory (XI) nerves.

17. Which bones form the jugular foramen?

The petrous part of the temporal bone and the occipital bone.

18. Which major venous sinus continues as the internal jugular vein at the jugular foramen?

The sigmoid sinus.

19. Which additional dural venous sinus drains through the jugular foramen?

The inferior petrosal sinus.

20. Which cranial nerve passes through the hypoglossal canal?

The hypoglossal nerve (cranial nerve XII).

21. Where is the hypoglossal canal located?

In the occipital bone, superior to the occipital condyle and anterolateral to the foramen magnum.

22. Which dural venous sinus runs along the superior border of the petrous temporal bone?

The superior petrosal sinus.

23. Which dural venous sinus occupies the sigmoid sulcus?

The sigmoid sinus, which continues toward the jugular foramen.

24. What is the internal occipital protuberance?

A midline bony prominence on the inner occipital surface near the confluence of the dural venous sinuses.

25. Which dural fold attaches to the internal occipital crest?

The falx cerebelli.

26. Which part of the ventricular system lies between the brainstem and cerebellum?

The fourth ventricle.

27. Which median opening allows cerebrospinal fluid to leave the fourth ventricle?

The median aperture, also called the foramen of Magendie.

28. Which paired openings connect the fourth ventricle with the subarachnoid space?

The lateral apertures, also called the foramina of Luschka.

29. What is the cerebellopontine angle?

A region between the cerebellum, pons, and petrous temporal bone containing important cranial nerves and vessels.

30. Why are expanding lesions of the posterior cranial fossa particularly dangerous?

The confined space allows compression of the brainstem and obstruction of cerebrospinal fluid pathways.