Base of Skull Flashcards

Explore the cranial base, including its fossae, contributing bones, foramina, neurovascular passages, articulations, and clinical landmarks.

Card 1 of 30Question

What is the base of the skull?

The inferior portion of the cranium that supports the brain and contains openings for neurovascular structures.

In This Section

1. What is the base of the skull?

The inferior portion of the cranium that supports the brain and contains openings for neurovascular structures.

2. What are the three major depressions on the internal surface of the cranial base?

The anterior, middle, and posterior cranial fossae.

3. Which bones contribute to the anterior cranial fossa?

The frontal, ethmoid, and sphenoid bones.

4. Which parts of the brain occupy the anterior cranial fossa?

The frontal lobes of the cerebral hemispheres.

5. Which bony landmarks mark the posterior boundary of the anterior cranial fossa?

The posterior margins of the lesser wings of the sphenoid and the anterior clinoid processes.

6. What is the crista galli?

A vertical projection of the ethmoid bone that provides attachment for the falx cerebri.

7. Which nerve fibers pass through the cribriform plate of the ethmoid bone?

Olfactory nerve fibers (cranial nerve I).

8. Which bones form most of the middle cranial fossa?

The sphenoid and temporal bones.

9. Which parts of the brain occupy the lateral portions of the middle cranial fossa?

The temporal lobes of the cerebral hemispheres.

10. What is the sella turcica?

A saddle-shaped depression on the superior surface of the sphenoid body containing the hypophyseal fossa.

11. Which endocrine structure occupies the hypophyseal fossa?

The pituitary gland.

12. Which structures pass through the optic canal?

The optic nerve (cranial nerve II) and ophthalmic artery.

13. Which cranial nerves pass through the superior orbital fissure?

The oculomotor (III), trochlear (IV), ophthalmic (V1), and abducens (VI) nerves.

14. Which cranial nerve passes through the foramen rotundum?

The maxillary nerve (V2), the second division of the trigeminal nerve.

15. Which cranial nerve passes through the foramen ovale?

The mandibular nerve (V3), the third division of the trigeminal nerve.

16. Which major artery enters the cranial cavity through the foramen spinosum?

The middle meningeal artery.

17. What is the relationship of the internal carotid artery to the foramen lacerum?

It passes across the superior aspect of the foramen after emerging from the carotid canal, rather than traversing it vertically.

18. Which bones primarily form the posterior cranial fossa?

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

19. Which major parts of the brain occupy the posterior cranial fossa?

The cerebellum, pons, and medulla oblongata.

20. What forms the clivus of the cranial base?

The sloping surface formed by the sphenoid body and basilar part of the occipital bone.

21. What is the largest opening in the cranial base?

The foramen magnum of the occipital bone.

22. Which major structures pass through the foramen magnum?

The medulla-spinal cord junction, vertebral arteries, spinal accessory nerve roots, and anterior and posterior spinal arteries.

23. Which cranial nerves enter the internal acoustic meatus?

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

24. Which cranial nerves pass through the jugular foramen?

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

25. Which major venous sinus drains through the jugular foramen into the internal jugular vein?

The sigmoid sinus.

26. Which cranial nerve passes through the hypoglossal canal?

The hypoglossal nerve (cranial nerve XII).

27. Which bony structures articulate with the atlas to form the atlanto-occipital joints?

The occipital condyles, located on either side of the foramen magnum.

28. What is the petro-occipital fissure?

The junction between the petrous temporal bone and the occipital bone on the cranial base.

29. Which fracture-related complication can result from injury to the cribriform plate?

Cerebrospinal fluid rhinorrhea, sometimes accompanied by olfactory nerve injury.

30. What is Battle's sign in a suspected skull base fracture?

Postauricular ecchymosis over the mastoid region, associated with a possible basilar skull fracture.