Intermediate Cerebrospinal Fluid Quiz

Q1. Why is the lumbar cistern a useful site for obtaining CSF in adults?

• It provides access to CSF below the usual end of the spinal cord
• It lies outside the meninges
• The spinal cord normally extends to the coccyx
• It contains no nerve roots

Q2. At which vertebral levels is lumbar puncture commonly performed in adults?

• L3-L4 or L4-L5
• T6-T7
• C1-C2
• T1-T2

Q3. Why are cauda equina roots relatively mobile during lumbar puncture?

• They are fixed to vertebral bodies
• They are suspended in CSF within the lumbar cistern
• They are enclosed in bone
• They lie outside the dural sac

Q4. Which structure bridges the CSF-filled subarachnoid space between arachnoid and pia?

• Interspinous ligaments
• Annulus fibrosus
• Ligamenta flava
• Arachnoid trabeculae

Q5. How does CSF contribute to buoyancy of the central nervous system?

• It replaces blood flow
• It reduces the effective weight of neural tissue
• It rigidly fixes the cord to bone
• It increases the density of neural tissue

Q6. Where is most CSF produced?

• Choroid plexuses of the cerebral ventricles
• Denticulate ligaments
• Spinal epidural fat
• Dorsal root ganglia

Q7. Through which opening is cranial subarachnoid CSF continuous with the spinal subarachnoid space?

• Optic canal
• Foramen magnum
• Internal acoustic meatus
• Foramen ovale

Q8. What distinguishes an intrathecal injection from an epidural injection?

• Intrathecal injection enters the subarachnoid space
• Intrathecal injection remains outside the dura
• Both injections enter the epidural space
• Epidural injection enters the spinal cord

Q9. Which structure forms the superficial boundary of the CSF-filled spinal subarachnoid space?

• Pia mater
• Arachnoid mater
• Ligamentum flavum
• Vertebral periosteum

Q10. What is the relationship of CSF to the conus medullaris?

• CSF continues below the conus within the lumbar cistern
• CSF ends exactly at the conus
• CSF is absent around the cauda equina
• CSF becomes epidural fat below the conus