Arrange the sequence of the Central Nervous System:
A. Dura mater
B. Sub-arachnoid space
C. Cerebrospinal Fluid
D. Arachnoid membrane
Choose the correct answer from the options given below:

Correct option is B

The correct sequence of the meninges and related structures from outermost to innermost is:
1. Dura mater (A) - The tough, outermost membrane
2. Arachnoid membrane (D) - The middle layer, web-like membrane
3. Sub-arachnoid space (B) - The space between arachnoid and pia mater
4. Cerebrospinal Fluid (C) - Found within the sub-arachnoid space

Information Booster: Key Points about CNS Protection

• Three-Layer Protection: The meninges consist of dura mater, arachnoid membrane, and pia mater (innermost, not listed in options)
• CSF Circulation: Cerebrospinal fluid circulates through the sub-arachnoid space, providing cushioning and nutrient transport
• Barrier Function: Each layer serves specific protective and metabolic functions for the brain and spinal cord
• Clinical Significance: Understanding this sequence is crucial for procedures like lumbar puncture and diagnosing meningitis
• Anatomical Continuity: These structures surround both the brain and spinal cord throughout the central nervous system
• Pathological Conditions: Disorders can affect specific layers (subdural hematoma, subarachnoid hemorrhage)