Question

The innermost layer of meninges is
A. Dura Mater
B. Piamater
C. Arachnoidmater
D. Cortex

Answer 1

Hint: The brain is soft and mushy, and needs structural support to maintain a normal shape. The bone of the skull and spine safeguards and structurally supports the central nervous system (CNS).

Complete answer:
The meninges are the membranes that encapsulate the brain and spinal cord and keep them safe from the walls of the skull and vertebral column. Based on their location, meninges are
> The cranial meninges which cover the brain.
> The spinal meninges which cover the spinal cord.
Each meninge consist of the three meningeal layers:
> Dura mater (pachymeninx)
> Arachnoid mater
> Pia mater
 Meningeal spaces – It is the space between the meningeal layers:
> the epidural
> subdural
> subarachnoid spaces.
The main function of the meninges is:
> Protect the brain and spinal cord from mechanical trauma.
> To support the blood vessels.
> To form a continuous cavity that makes the passage for the cerebrospinal fluid (CSF).
To be precise, the CSF passes between the arachnoid and pia mater. Together they are called the leptomeninges.

So, the correct answer is (B) Piamater.

Note:
Every organ in the body has some protective mechanism that shields it from external trauma or injury. Either bones protect them or thick capsules around serve their protection. Others are covered by both of them. The same is true for the central nervous system. Both the brain and spinal cord are protected by a thick bony framework of the skull and vertebral column, respectively. Also, both these structures have additional protection provided by capsule-like thick membranes called meninges. Meninges not only protect from physical injury and trauma to the brain and spinal cord but also perform several other functions that are essential for the survival of these organs. The meninges of the brain and spinal cord include three layers; dura mater, arachnoid mater and pia mater.