nervous system

Debate and discussion of any biological questions not pertaining to a particular topic.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
melgo
Garter
Garter
Posts: 1
Joined: Tue Oct 25, 2005 2:10 am

nervous system

Post by melgo » Tue Oct 25, 2005 2:15 am

Why can a nervous impulse only be sent in one direction?

User avatar
mith
Inland Taipan
Inland Taipan
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN
Contact:

Post by mith » Tue Oct 25, 2005 4:55 am

because the receptors cannont send signals.
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr

vinaya
Death Adder
Death Adder
Posts: 78
Joined: Tue Sep 06, 2005 2:17 pm

Post by vinaya » Tue Oct 25, 2005 3:30 pm

the dendrites bring impulses towards the cell body, i.e. the cell with cytoplam and nucleus.
the axon transmits impulses away from the cell body towards another neuron's dendrites.thus the movement is unidirectional because the axon cannot transmit impulses towards the cell body & similarly the dendrites also cant transmit impulses away from the cell :wink:

User avatar
canalon
Inland Taipan
Inland Taipan
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Post by canalon » Tue Oct 25, 2005 3:40 pm

vinaya wrote:the dendrites bring impulses towards the cell body, i.e. the cell with cytoplam and nucleus.
the axon transmits impulses away from the cell body towards another neuron's dendrites.thus the movement is unidirectional because the axon cannot transmit impulses towards the cell body & similarly the dendrites also cant transmit impulses away from the cell :wink:


But if you put an electrode in an axon (or a dendrite) and give an impulse you will see that it propagates in both directions :twisted:
So the directionnality of the nerve impulse do not come from a particularity of the axons or dendrites ability to directionnaly transfer impulses. It all comes from the synapse! In the synaptic junction, dendrites have receptors only for neurotransmitters, and axones just a way to pass those molecules, hence the directionnality.

Patrick

User avatar
MrMistery
Inland Taipan
Inland Taipan
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)
Contact:

Post by MrMistery » Tue Oct 25, 2005 6:47 pm

True, but something has been missed: electrical synapses. In these synapses, that do not have any neurotransmitter, the impulse moves both ways... This is a good proof of what Patrick pointed out...
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

baikuza
Coral
Coral
Posts: 429
Joined: Tue Aug 30, 2005 10:09 am
Location: Yogyakarta, indonesia, south-east asia
Contact:

Post by baikuza » Wed Oct 26, 2005 3:41 am

hei..
i think it is so un..comfortable if two kind of information are pass at same time and same place...
_______
awake from the day
knowing u r talking together
i just wanna to join the fun

User avatar
victor
King Cobra
King Cobra
Posts: 2668
Joined: Sat Apr 30, 2005 12:01 pm
Location: Yogyakarta, Indonesia..
Contact:

Post by victor » Wed Oct 26, 2005 12:03 pm

Do you know a case named simultaneous action? (take a look at your physics book: general relativity)...you have to know that there're no 2 actions that happen together and our bodies' response is very highly accurate to it so they know what will they response..(at least that's the conclusion that I made)
Q: Why are chemists great for solving problems?
A: They have all the solutions.

baikuza
Coral
Coral
Posts: 429
Joined: Tue Aug 30, 2005 10:09 am
Location: Yogyakarta, indonesia, south-east asia
Contact:

Post by baikuza » Thu Oct 27, 2005 1:19 pm

hei so that i think if it was it sould make a... dizy syndroma(.. it's okay if i said 'Syndroma')

Post Reply

Who is online

Users browsing this forum: Google Adsense [Bot] and 6 guests