Chapter 2 : Meningen and Cerebrospinal Fluid (2)

Question 1

1. Which one of the following is only a potential space?
   (A) Subarachnoid space
   (B) Subarachnoid cistern
   (C) Spinal epidural space
   (D) Cerebral aqueduct
   (E) Cranial epidural space

Answer 1

l-E. The cranial epidural space and the subdural space are normally potential spaces.
Hemorrhage of a meningeal artery creates an epidural space between the periosteal and
meningeal layers of the dura (epidural hematoma). Laceration of the superior cerebral veins
(“bridging veins”) as they enter the superior sagittal sinus creates a subdural space between
the dura and the arachnoid (subdural hematoma).

Question 2

2. The cranial dura is innervated by the
   (A) ophthalmic nerve
   (B) facial nerve
   (C) intermediate nerve
   (D) glossopharyngeal nerve
   (E) major petrosal nerve

Answer 2

2-A. The cranial dura is innervated by the trigeminal nerve (CN V), the meningeal (recurrent)
branches of the vagal nerve (CN X), and the upper spinal nerves (CI and C2), via the hypoglossal
nerve (CN XII).

Question 3

3. The calcified glomus of the choroid plexus, which is visible on x-ray and computed tomography (CT), is seen in the
   (A) frontal horn
   (B) third ventricle
   (C) occipital horn
   (D) trigone
   (E) fourth ventricle

Answer 3

3-D. The calcified glomus is found in the trigone of the lateral ventricle. It, as well as the calcified
pineal gland, can be seen on x-ray and computed tomography (CT) [but not on magnetic
resonance image (MRI)].

Question 4

4. Which one of the following statements concerning the spinal epidural space is true?
   (A) It contains the denticulate ligaments
   (B) It contains cerebrospinal fluid (CSF)
   (C) It contains the dorsal root ganglia
   (D) It may be injected with an anesthetic to produce a paravertebral nerve block
   (E) It contains the cauda equine

Answer 4

4-D. The spinal epidural space contains loose areolar tissue, venous plexuses, and lymphatics.
It may be injected with an anesthetic to produce a paravertebral nerve block. The denticulate
ligaments are subdural pial structures that extend from the surface of the spinal cord and
attach to the internal surface of the dura. The dorsal root ganglia are located within the intervertebral
foramina. Cerebrospinal fluid (CSF) and the cauda equina are found in the subarachnoid
space.

Question 5

5. The caudate nucleus is a boundary of all of the following structures EXCEPT the
   (A) frontal horn
   (B) body of the lateral ventricle
   (C) occipital horn
   (D) trigone
   (E) temporal horn

Answer 5

5-C. The caudate nucleus forms the lateral wall of the frontal horn, body, trigone of the lateral
ventricle, and the roof of the temporal horn. It does not extend into the occipital horn.

Question 6

6. All of the following statements concerning the pia mater are correct EXCEPT it
   (A) is a delicate, highly vascular layer of connective tissue
   (B) gives rise to the denticulate ligaments
   (C) extends into the sulci and fissures
   (D) is connected to the arachnoid by trabeculae
   (E) is a boundary of the epidural space of the vertebral canal

Answer 6

6-E. The pia mater is a delicate, highly vascular layer of connective tissue, which gives rise to
the denticulate ligaments. It extends into the sulci and fissures of the brain and spinal cord
and is connected via trabeculae to the arachnoid membrane. The spinal epidural space lies
between the dura and the periosteum of the vertebrae; it contains loose areolar tissue and a
venous plexus.

Question 7

7. All of the following statements concerning the arachnoid granulations are correct EXCEPT they
   (A) are found along the superior sagittal sinus
   (B) project into the dural venous sinuses
   (C) play a role in the absorption of cerebrospinal fluid (CSF)
   (D) produce CSF
   (E) consist of arachnoid villi

Answer 7

7-D. Arachnoid granulations are tufts of pia—arachnoid tissue that extends into the venous
 lacunae or directly into the venous dural sinuses. Microscopically, they are arachnoid villi and
 are prominent along the superior sagittal sinus. They play a major role in the absorption of
 cerebrospinal fluid (CSF).

Question 8

8. All of the following statements concerning the dura mater are correct EXCEPT it
   (A) forms the periosteum of the vertebral canal
   (B) forms the walls of the venous sinuses
   (C) forms the roof of the pituitary fossa
   (D) is innervated by two cranial nerves
   (E) is continuous with the sclera of the eyeball

Answer 8

8-A. The dura mater forms the walls of the venous sinuses and the diaphragma sellae, which
form the roof of the hypophyseal fossa. The dura of the anterior and middle cranial fossae is
innervated by the ophthalmic and maxillary divisions of the trigeminal nerve (CN V). The
infratentorial dura of the posterior cranial fossa is innervated by the vagal nerve (CN X) and
the meningeal branches of the upper cervical spinal nerves. The spinal dura consists of one
layer, the meningeal dura; it does not form the periosteum of the vertebrae. The dura is continuous
with the sclera; it forms the outer connective tissue layer of the optic nerve (CN II).

Question 9

9. All of the following statements concerning the cranial epidural space are correct EXCEPT it
   (A) contains a branch of the facial artery
   (B) contains meningeal veins
   (C) usually is associated with arterial hemorrhage
   (D) is bounded by two layers of dura
   (E) is normally a potential space

Answer 9

9-A. The cranial epidural space is actually a potential intradural space that is created only
after trauma and hemorrhage. Epidural hematomas are arterial hemorrhages. The cranial
epidural space lies between tbe periosteal and meningeal dural layers. Meningeal arteries and
veins are found in this space.

Question 10

10. All of the following statements concerning the subarachnoid space are correct EXCEPT it
    (A) communicates via the foramina of Luschka with the fourth ventricle
    (B) is found between the arachnoid and the pia mater
    (C) extends, in the adult, from the conus medullaris to S2
    (D) is lined with ependymal cells
    (E) communicates via the median foramen of Magendie with the fourth ventricle

Answer 10

10-D. The subarachnoid space is found between the arachnoid and the pia. It extends in the
adult from the conus medullaris to S2. The subarachnoid space is lined with leptomeningeal
(mesothelial) cells. The subarachnoid space communicates via the foramina of Luschka and the
median foramen of Magendie with the fourth ventricle. Ependymal cells line the ventricles.

Question 11

11. All of the following statements concerning meningiomas are correct EXCEPT they
    (A) are derived from arachnoid cells
    (B) are characterized by cellular whorls and psammoma bodies
    (C) are more frequent in males
    (D) are benign, slow growing, and well-circumscribed tumors
    (E) comprise approximately 20% of primary intracranial tumors

Answer 11

11-C. Meningiomas occur more frequently in women (60%) than in men.

Question 12

12. Olive

Answer 12

12-E. The olive is a prominent surface structure of the medulla.

Question 13

13. It contains the trochlear nerve (CN IV)

Answer 13

13-D. The ambient cistern contains the trochlear nerve.

Question 14

14. Its stenosis results in hydrocephalus

Answer 14

14-C. Stenosis of the cerebral aqueduct prevents cerebrospinal fluid (CSF) from entering the
fourth ventricle; this results in a noncommunicating hydrocephalus.

Question 15

15. Contains a calcified glomus

Answer 15

15-B. The trigone of the lateral ventricle contains a large tuft of choroid plexus called the glomus.
It is usually calcified and highly visible in computed tomography (CT) images.

Question 16

16. Receives cerebrospinal fluid (CSF) from the arachnoid villi

Answer 16

16-A. The superior sagittal sinus receives cerebrospinal fluid (CSF) via the arachnoid villi.

Question 17

17. Superior cistern

Answer 17

17-C. The superior (quadrigeminal) cistern overlies the dorsal aspect of the midbrain.

Question 18

18. Blockage results in hydrocephalus

Answer 18

18-B. Blockage of the interventricular foramen of Monro (e.g., due to a colloid cyst of the third
ventricle) results in hydrocephalus involving the lateral ventricle.

Question 19

19. Lateral ventricle

Answer 19

19-A. The lateral ventricle is seen between the corpus callosum and the fornix.

Question 20

20. Contains the two foramina of Luschka

Answer 20

20-D. The fourth ventricle contains the two foramina of Luschka that drain into the two cerebellopontine
angle cisterns.

Question 21

21. Receives cerebrospinal fluid (CSF) via the foramen of Magendie

Answer 21

21-E. The cerebellomedullary cistern receives cerebrospinal fluid (CSF) via the foramen of
Magendie.