Spinal cord is about 45 cm in males and 43 cm in females, cylindrical in shape and lies in the vertebral canal.
What we feel at the centre of our back, the backbone, is the vertebral column and has spinal cord inside it.
Spinal cord is covered by membranous sheath called Meninges.
Meninges are Dura matter, Pia matter and Arachnoid matter and these continue to cover the brain as well.
The Brain and the Spinal cord constitute the Central Nervous system.
The spinal cord has 12 pairs of cranial nerves and 31 pairs of spinal nerves.
The 12 cranial nerves are,
1. Olfactory Nerve
2. Optic Nerve
3. Oculomotor Nerve
4. Trochlear Nerve
5. Trigeminal Nerve
6. Abducens Nerve
7. Facial Nerve
8. Auditory Nerve
9. Glossopharyngeal
10. Vagus Nerve
11. Spinal Accessory Nerve
12. Hypoglossal Nerve
![parts of meningis](https://www.irastoworldhealth.com/wp-content/uploads/2015/12/meningis.webp)
It is surrounded by vertebrae, which include
• Cervical — C1 to C7
• Thoracic – T1 to T12
• Lumbar – L1 to L5
• Sacral — S1 to S5
Lumbar Puncture is done between L3 to L4 to draw CSF (Cerebro-Spinal Fluid) fluid for diagnostic purposes or for drug administration during anesthesia.