RE: [HAPS-L] Cauda Equina

["Druzinsky, Robert" <R-DRUZINSKY@xxxxxxxxx>]

I agree.  The dorsal and ventral roots, which merge to form the spinal nerves, are parts of the peripheral nervous system.  The junctions of the CNS and PNS are the entry and exit zones of the roots. (See British Gray's for a reference.)  The axons of all of the myelinated fibers in these, both motor and sensory, are associated with Schwann cells.

 

The distinction between the CNS and PNS is, perhaps, clearer in "primitive" chordates, in which the dorsal and ventral roots remain separate, never merging to form mixed spinal nerves.

 

Hope this helps,

 

Robert

 

Robert Druzinsky, Ph.D.

Associate Professor of Anatomy and Neuroscience

Governors State University

1 University Parkway

University Park, IL 60466 USA

 

Phone:  708-235-2147

Fax:      708-534-1647

Cell:      224-436-0602

 

Email:  r-druzinsky@xxxxxxxxx

 

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From: Ken Saladin
Sent: Wed 3/21/2007 8:20 PM
To: HAPS-L@xxxxxxxxxxx
Subject: RE: [HAPS-L] Cauda Equina

Spinal nerves, as well as the dorsal and ventral roots of the spinal nerves, are not typically considered to be part of the CNS, even though the proximal portions of the ventral and dorsal roots are covered by meninges. So, even through there is no clear cut definition in the sources I can find, my vote would be that the cauda equina is NOT part of the CNS

Bob Tallitsch

Mine too.

Ken