Question

Epidural blocks are the injection of an anesthetic agent into the _______ space above the dura mater?

1) Subdural
2) Subarachnoid
3) Epidural
4) Intrathecal

Answer 1

Epidural blocks involve administering anesthetic into the epidural space, which is option 3) Epidural. This space is located above the dura mater and outside of the subarachnoid space that contains CSF.

Step-by-step explanation:

Epidural blocks are the injection of an anesthetic agent into the epidural space above the dura mater. The correct answer to the question is option 3) Epidural.

The epidural space is the area between the dura mater and the inside of the vertebral canal. This space is outside of the dura mater, a tough membrane that encloses the spinal cord and cerebrospinal fluid (CSF).

In contrast, the subdural and subarachnoid spaces are interior to the dura mater, with the subarachnoid space containing circulating CSF and serving as a liquid cushion for the central nervous system (CNS). The intrathecal space is effectively another term for the subarachnoid space, as 'intrathecal' means within the sheath, referring to the injection or occurrence within the subarachnoid or subdural space.