I am currently studying for A-Level (pre-university) biology, and we have
come to the topic of the autonomic nervous system.
There is one thing that is bugging me about this subject, my teacher
doesn't know the answer and I can't find any relevant information on it
My question is about the differences between sympathetic and
As I understand it from my (probably over-simplified) text book, is that
sympathetic (motor) neurones have a short preganglionic neurone, linked
to a long postganglionic neurone. The ganglion is close to the part of
the CNS it left i.e. the spinal cord.
So why do the sympathetic neurones have a long preganglionic neurone and
a short postganglionic neurone, and why is the ganglion found near to (or
in the) effector?? Also why do parasympathetic fibres only leave from the
base of the brain and the spine (forgot the proper names!)??
Any info would be appreciated. Also any good URL's for nerve impulses
(i.e. the Na & K gradients) at A-Level standard would be much
appreciated, as I only sort of get it at the moment - I like to have a
full understanding of these things, otherwise I don't remember them )-:
john at gorst.demon.co.uk
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