[Eileen Field]

Eileen Field  asked the Naked Scientists:
   Dear Dr Chris, I wonder if you or one of your team can help us out. I am the head teacher of a virtual school. We are a secondary school, where youngsters who can't or shouldn't attend a mainstream classroom come along for KS3 and GCSE studies.  

Along side maths and English we teach Science and today, my
Head of Science, Sue Robinson was working with one of our year 11 revision classes on the nervous system  Â and the following question was raised by a group of students from Peterborough PRU as follows.


This may sound random, but it's a semi-genuine question on nervous
system revision from the Peterborough  express posse today.  We were discussing the fact that relay neurones in the spinal cord can mediate reactions without needing to involve the brain directly (is this actually true...?).

If this is the case, they wondered, does that make the spinal cord a
bit like the brain (well, yes, a bit, I suppose...) and - ARE SHORT PEOPLE
THEREFORE MORE STUPID?? Or at least, if you're short does that affect your nerve function in some way?    

I reckon not, cos surely it's the number of cell bodies that matters
and if you have a longer spine then you've just got longer axons and
stuff...And in fact, messages may take longer to reach the brain if you're tall so you are more likely to be slow on the uptake, I'd say...

But now I've got my cat home from the vet, with an amputated tail (lots
of back-boney bits lost there, and nerves...)...so...could maybe test it on him? But he's always been daft as a brush anyway so since he's actually breathing and eating at the same time I assume his loss has not significantly lowered his cognitive function.

Just musing really, but would welcome your views! (ones like "you
really should get out more" or "for god's sake did you REALLY manage
to get any kids through A level biology, ever?" , for example...)

Love and ignorance (but then  I am quite tall...)

As these students sit their Science GCSE next week all help would be most appreciated!

Warmest regards,

Eileen Field

What do you think?

[DrN]

I'm not a neuroscientist, or a neurologist, but I think the nervous impulses that do not involve the brain are reflex reactions. I doubt very much of the length of the spinal cord has anything to do with it, as it seems to be a local response. Moreover, the length of the spinal cord is generally in proportion to the body that it serves, so a longer spinal cord in a taller person is no different to a shorter spinal cord in a shorter person.

Actually, I almost wonder if the opposite could be true - not that taller people are stupider (you don't need the spinal cord to think) - but that for those impulses that are required to be mediated by the brain, they must take longer to reach the brain in taller people? I expect the time difference is so miniscule as to be negligable, but it's an interesting thought. Also this would only apply for the types of impulses that originated in the extremeties, e.g. putting your big toe in a bath of very hot water.

The other thing that would be intersting to find out is the incidence of demylelinating disease in taller people vs shorter people. I would guess taller people have more mylelin in total, as they must surely have longer neurons, so does this make them more susceptible to damage and degeneration?

Ok, sorry, I'm asking more questions than I'm answering!

[JnA]

DrN  is on the money.. you are talking about reflex actions. The 'message' goes from origin site to spinal cord back to site of origin. It's a no brainer.
Reflex actions are there as a 'safety and function mechanism'. They are involuntary actions. The spinal cord is not like the brain.. the brain can function without the spinal cord and the spinal cord has limited function without the brain.
Note that the length of the spinal cord is approximately the same in most people since height is more determined by leg length than torso length.

[Chemistry4me]

Very tall people faint more easily than short people when they stand for a long time, not enough blood to the head, so you can argue they are less intelligent.

[DrN]

So then they must be super intelligent when standing on their heads.  []

[DrN]

It's a no brainer.

 [] [] []

[DrN]

Note that the length of the spinal cord is approximately the same in most people since height is more determined by leg length than torso length.

Yes, this is generally true, but there is considerable variation in torso length too ... you try buying a swimsuit if you're not 'average'.

[Make it Lady]

My husband and children have long torsos and short legs. It is like a hall of mirrors in our house. I love children's questions. They are the best scientists when it comes to questions.

[lyner]

Are giraffes particularly clever?