Question

Correct the following statement by changing the underlined word.
The outermost layer of Meninges is the Pia mater.

Answer 1

Hint: A thick membrane composed of dense irregular connective tissue that covers the brain and spinal cord is the outermost layer of Meninges. The arachnoid substance is enveloped by this membrane. This region derives its name from the Latin word meaning “tough mother”.

Complete step by step answer:
Meninges refer to the brain and spinal cord membranes. Three layers, namely dura mater, arachnoid mater, and pia mater, constitute the meninges that are present around the brain. Dura mater is referred to as the outermost layer of the meninges. The pia mater is the innermost layer of the meninges. The middle layer of the meninges, located immediately under the dura mater, is the arachnoid mater.
Directly under the bones of the skull and vertebral column lies the dura mater. It's tough, thick, and inextensible.

The dura comprises two connective tissue sheets inside the cranial cavity:
- The periosteal layer lines the inner surface of the cranium bones.
- Meningeal layer- deep into the periosteal layer within the cranial cavity. In the vertebral column, it is the only layer present.
The dura covers the spinal cord and the brain. The arachnoid material, which is responsible for holding the cerebrospinal fluid, is enveloped. It is derived predominantly from the population of neural crest cells, with the paraxial mesoderm making postnatal contributions.
So, the correct answer is, ‘Dura mater’.

Note: There are two main roles in the coverings of meninges. They are:  
- Provide the cerebral and cranial vasculature with a supporting structure.
- Acting with cerebrospinal fluid to avoid mechanical damage to the CNS.
Meninges, as a common site of infection (meningitis) and intracranial bleeding, is also involved in cerebral pathology.