Finding limitations in Naturalism

[Michael]

Considering I've actually worked in an electrophysiology lab studying neurons, your really barking up the wrong tree pretending to understand these things I've worked with professionally when you and Michael are more clueless than the average undergrad.

That's all nice talk and all, but so far you've presented nothing in the way of evidence to support your case. In fact however, every reference I have cited talked about voltage differences and charged particle movement (AKA CURRENT). So far all we've seen from you is attitude.

 

[Michael]

Perhaps you can explain why a nerve impulse moves at 100 m/s while an electrical current moves at speeds orders of magnitude higher than that.

Currents move at *lots* of speeds. Not all current is in the form of electrons either! Any moving charged particle is a form of "current".

 

[kellhus]

That's all nice talk and all, but so far you've presented nothing in the way of evidence to support your case. In fact however, every reference I have cited talked about voltage differences and charged particle movement (AKA CURRENT). So far all we've seen from you is attitude.

Charged particle movement ACROSS a cell membrane, not down the length of it. Is this really too complicated for you to grasp? Do you know what the words "cell" and "membrane" mean?

 

[Loudmouth]

That's all nice talk and all, but so far you've presented nothing in the way of evidence to support your case. In fact however, every reference I have cited talked about voltage differences and charged particle movement (AKA CURRENT). So far all we've seen from you is attitude.

So far, you can't seem to explain why a nerve impulse moves at 100 m/s while electrical currents in conductors can move at nearly 299,792,458 m/s.

 

[Loudmouth]

Currents move at *lots* of speeds.

Not at 100 m/s. A nerve impulse is a wave of proteins changing their tertiary structure. It is not a current.

 

[Michael]

Charged particle movement ACROSS a cell membrane, not down the length of it. Is this really too complicated for you to grasp? Do you know what the words "cell" and "membrane" mean?

When the charged particle moves *anywhere* inside the brain due to voltage differences, is becomes a form of *current*. It's happening all over the brain. Whine and moan all you like, but that's the bottom line.

 

[Michael]

Not at 100 m/s. A nerve impulse is a wave of proteins changing their tertiary structure. It is not a current.

Everyone else called it a current, including WIKI, and including your own link! Neither of you have presented any evidence to the contrary in fact.

 

[Loudmouth]

When the charged particle moves *anywhere* inside the brain due to voltage differences, is becomes a form of *current*. It's happening all over the brain. Whine and moan all you like, but that's the bottom line.

But a nerve impulse is not a current. Whine and moan all you like, but that's the bottom line.

Even more, the astronomical structures you point at do not have anything analogous to nerve impulses.

 

[Loudmouth]

Everyone else called it a current,

No, they call it an action potential.

"In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and endocrine cells, as well as in some plant cells."

http://en.wikipedia.org/wiki/Action_potential

 

[kellhus]

Everyone else called it a current, including WIKI, and including your own link! Neither of you have presented any evidence to the contrary in fact.

Dear god, you look so ridiculous pretending Wikipedia is some authoritative source. The conventional phrase is ion flux or flow. Nobody pretends that ions moving in an action potential is an electrical current.

 

[Michael]

No, they call it an action potential.

Nope. Your own reference says and I quote:

"A nerve impulse is an electrical current....."

 

[kellhus]

Nope. Your own reference says and I quote:

"A nerve impulse is an electrical current....."

Then loudmouths source is wrong. Because that is about the first true false question on every introductory undergrad neuro class midterm, and the correct answer is false.

 

[Michael]

Dear god, you look so ridiculous pretending Wikipedia is some authoritative source.

If you had a 'better' one, I'd consider it. You look pretty ridiculous to me waving your hand around and providing no references to support your claims too.

Animation: The Nerve Impulse

Oh look, McGraw-Hill called it a current too.

The conventional phrase is ion flux or flow. Nobody pretends that ions moving in an action potential is an electrical current.

As far as I know only you and LM "pretend" that moving ions are not a form of current. Every other references that has been cited in this thread called it a *current*, not just me! In fact you've yet to produce any reference that says *it's not a current*.

 

[Justatruthseeker]

You mean the net movement of electrons through a conductor? Nothing like that occurs in nerves. Nerves are not copper wires, and they are certain not plasma. Nothing analogous to nerve impulses occur in the structures that Michael is pointing to.



Then show it to me.



And in the case of the nerve cell, this voltage difference does not exist at the ends of the nerve. The nerve impulse is much more like a row of dominoes than an electrical current. This is why it moves at a near crawl compared to electrical currents.

This is an electrolyte:
electrolyte - definition of electrolyte by the Free Online Dictionary, Thesaurus and Encyclopedia.

1. A chemical compound that ionizes when dissolved or molten to produce an electrically conductive medium.
2. Physiology Any of various ions, such as sodium, potassium, or chloride, required by cells to regulate the electric charge and flow of water molecules across the cell membrane.

I shouldn't need to say anymore.

As I said you misinterpret what electricity is.

How fast do electrons travel when moving as an electrical current through copper wire?

The average drift speed of electrons in a wire is comparatively slow, they do not move at the speed of c through the wire. The EM field generated by them moves at c.

Electroencephalography - Wikipedia, the free encyclopedia
The brain's electrical charge is maintained by billions of neurons. Neurons are electrically charged (or "polarized") by membrane transport proteins that pump ions across their membranes. Neurons are constantly exchanging ions with the extracellular milieu, for example to maintain resting potential and to propagate action potentials. Ions of similar charge repel each other, and when many ions are pushed out of many neurons at the same time, they can push their neighbours, who push their neighbours, and so on, in a wave. This process is known as volume conduction. When the wave of ions reaches the electrodes on the scalp, they can push or pull electrons on the metal on the electrodes. Since metal conducts the push and pull of electrons easily, the difference in push or pull voltages between any two electrodes can be measured by a voltmeter. Recording these voltages over time gives us the EEG[/quote]

Just check it out my man.

Scientists record the first video of thoughts forming in the brain

How Do Neurons Communicate?

Neurons communicate by sending electrical signals throughout the body....The responsibility of the axon is to transmit the signal from one neuron and then pass it to another neuron....If enough of the receptors are activated, the dendrite is activated and an electrical impulse is sent down through the dendrite to the body of the neuron containing the information.

Synapse - Wikipedia, the free encyclopedia

n an electrical synapse, the presynaptic and postsynaptic cell membranes are connected by special channels called gap junctions that are capable of passing electric current, causing voltage changes in the presynaptic cell to induce voltage changes in the postsynaptic cell. The main advantage of an electrical synapse is the rapid transfer of signals from one cell to the next.
When neurons receive or send messages, they transmit electrical impulses along their axons, which can range in length from a tiny fraction of an inch (or centimeter) to three feet (about one meter) or more. Many axons are covered with a layered myelin sheath, which accelerates the transmission of electrical signals along the axon. This sheath is made by specialized cells called glia.

Glia, the natural insulation of the brain similar to that we put on electric wires.
Neuroglia - Wikipedia, the free encyclopedia

 

[Loudmouth]

Nope. Your own reference says and I quote:

"A nerve impulse is an electrical current....."

"In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory"
Action potential - Wikipedia, the free encyclopedia

 

[Michael]

Then loudmouths source is wrong.

So WIKI is wrong, and McGraw-Hill is wrong, but you can't come up with any single external reference that supports your (rather absurd) claim that no currents flow in the human brain?

 

[Loudmouth]

This is an electrolyte:
electrolyte - definition of electrolyte by the Free Online Dictionary, Thesaurus and Encyclopedia.

Nerve impulses are waves of changes in the tertiary structure of proteins. It is much more analogous to a line of dominoes being tipped over, and then having them stood back up behind the moving pulse. Nerve impulses are not a current from one end of the nerve to the other, nor are they loosely spaced plasma in space.

As I said you misinterpret what electricity is.

You misinterpret what a nerve impulse is.

The average drift speed of electrons in a wire is comparatively slow, they do not move at the speed of c through the wire. The EM field generated by them moves at c.

Electroencephalography - Wikipedia, the free encyclopedia
The brain's electrical charge is maintained by billions of neurons. Neurons are electrically charged (or "polarized") by membrane transport proteins that pump ions across their membranes. Neurons are constantly exchanging ions with the extracellular milieu, for example to maintain resting potential and to propagate action potentials. Ions of similar charge repel each other, and when many ions are pushed out of many neurons at the same time, they can push their neighbours, who push their neighbours, and so on, in a wave. This process is known as volume conduction. When the wave of ions reaches the electrodes on the scalp, they can push or pull electrons on the metal on the electrodes. Since metal conducts the push and pull of electrons easily, the difference in push or pull voltages between any two electrodes can be measured by a voltmeter. Recording these voltages over time gives us the EEG

That is not a nerve impulse.

Glia, the natural insulation of the brain similar to that we put on electric wires.
Neuroglia - Wikipedia, the free encyclopedia

A massive oversimplification. Can you show me the equivalent of Nodes of Ranvier on an insulated conductor?

Myelin sheath gap - Wikipedia, the free encyclopedia

 

[Michael]

"In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory"
Action potential - Wikipedia, the free encyclopedia

Do you even read your own links?

Currents produced by the opening of voltage-gated channels in the course of an action potential are typically significantly larger than the initial stimulating current. Thus, the amplitude, duration, and shape of the action potential are determined largely by the properties of the excitable membrane and not the amplitude or duration of the stimulus. This all-or-nothing property of the action potential sets it apart from graded potentials such as receptor potentials, electrotonic potentials, and synaptic potentials, which scale with the magnitude of the stimulus. A variety of action potential types exist in many cell types and cell compartments as determined by the types of voltage-gated channels, leak channels, channel distributions, ionic concentrations, membrane capacitance, temperature, and other factors.

 

[Loudmouth]

Do you even read your own links?

Do you? The nerve impulse is not the movement of current from one end of the nerve to the other. The only movement of ions occurs across the membrane to the outside of the cell at a right angle to the actual nerve impulse. Like I said in other posts, it is much more analogous to a row of dominoes being tipped over.

 

[kellhus]

I don't quite understand why Michael and justatruth have such a desperate obsession with having ion flux across a membrane at Nodes of Ranvier called an electrical current.