The document summarizes key aspects of the central nervous system, including: 1. The meninges (dura mater, arachnoid, pia mater) surround and protect the brain and spinal cord. Cerebrospinal fluid is produced and circulated within the subarachnoid space. 2. The spinal cord contains gray matter for processing sensory and motor functions and white matter tracts for ascending and descending signals. It extends from the brainstem down through the vertebral column. 3. Spinal nerves emerge from the spinal cord to innervate the body, carrying sensory information to the cord and motor commands away from it. Reflexes are automatic responses mediated by spinal cord circuits.

3. The meninges

5. Hydrocephalus?

6. Arachnoid granulations: This is where the CSF produced in the choroid plexuses of the ventricles and which has circulated into the subarachnoid space is reabsorbed. Longitudinal fissure

10. Cervical Enlargement Gray matter expanded to incorporate more sensory input from limbs and more cell bodies for motor control of limbs

11. Lumbar Enlargement See fig 14-1

12. Spinal Meninges 3) Pia mater 2) Arachnoid 1) Dura mater Three membranes surround all of CNS 1) Dura mater - "tough mother", strong. Note the Epidural Space. 2) Arachnoid - spidery looking, carries blood vessels, etc. Note the Subarachnoid space which contains CSF 3) Pia mater - "delicate mother", adheres tightly to surface of spinal cord 2a) Subarachnoid Space

13. Transverse Section Fig 13.30 Compare the spinal roots with the model of the vertebral column in the lab. Note that the dura covers both the dorsal and ventral roots.

15. Sectional anatomy of spinal cord Outer white part; inner gray butterfly

16. Lumbar Puncture (= Spinal Tap) For clinical examination of CSF or administration of radiopaque dyes, drugs and anesthetics However: mostly “epidurals” for anesthetics L3 S1

21. Ascending and Descending Tracts