Extends between adjacent verterbrae, fuses with connective tissue around spinal nerves. Epidural block affects only nearby nerves, temporary, motor paralysis. Spinal tap needle into lower lumbar subarachnoid because no spinal cord. Pia mater Meshwork of collagen and elastic fibers interwoven with subarachnoid space Blood vessels for spinal cord in pia mater. Firmly bound to neural tissue underneath Denticulate ligaments from pia mater, arachnoid, dura mater, on either side of spinal cord to keep meninges in place.
Meninges pass thru intervertebral foramina, continuous with connective tissue around spinal nerves.
Sensory nuclei receive and relay info from peripheral receptors Motor nuclei sends commands to peripheral effectors. Very precise arrangment of nuclei for muscles of limbs, flexors separate from extensors If damaged, predict problem from where damage is. MS attacks white matter of lateral and posterior columns or along tracts to brain. Paralysis from physical damage, tracts seldom repair. Endoneurium - delicate connective tissue around individual axons.