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Author Topic: Where does our bodies get electricity from?  (Read 2875 times)

Offline GlentoranMark

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Where does our bodies get electricity from?
« on: 14/11/2010 13:11:20 »
I read that the brain works by electrical impulses but where does our bodies generate the electric? Have we a built in battery?


 

SteveFish

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Where does our bodies get electricity from?
« Reply #1 on: 14/11/2010 18:29:10 »
The inside of all the cells in your body is electrically negative relative to the extracellular space, so each cell is a sort of battery. Actually the cell membrane becomes charged up like a capacitor. The mechanism by which the membrane maintains its charge is complicated, but the main power for this comes from membrane molecular machines that pump potassium out of cells and sodium in. Three quarters of the food energy that your brain cells use is for running these pumps.
 

Offline ammara_khan

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Where does our bodies get electricity from?
« Reply #2 on: 10/12/2010 17:52:31 »
It's basically charged ions that flow through our body. An electric current can be defined as a flow of electrons or charged particles :)
 

Offline CliffordK

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Where does our bodies get electricity from?
« Reply #3 on: 10/12/2010 23:40:21 »
but the main power for this comes from membrane molecular machines that pump potassium out of cells and sodium in. Three quarters of the food energy that your brain cells use is for running these pumps.

Isn't it the other way around.
Potassium (K+) is pumped into the cells.
Sodium (Na+) is pumped out.

That is why an IV injection of Potassium (K+) could potentially be lethal by breaking down this gradient too fast.

The action potentials are propagated by opening Sodium Channels, and allowing Sodium to enter the cells from the extracellular space.  Then, after the action potential, the cells resume pumping the Sodium back out.
 

SteveFish

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Where does our bodies get electricity from?
« Reply #4 on: 11/12/2010 01:16:04 »
Clifford:

You are correct. Yet another embarrassment. Below is the summary slide I made for when I was lecturing this.

Steve

 

Offline CliffordK

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Where does our bodies get electricity from?
« Reply #5 on: 11/12/2010 04:40:56 »
You are correct. Yet another embarrassment.

Ahhh...  it happens to everyone. 
Even the Prof?

Nice diagram...  it takes a few seconds to get oriented...  so the pump runs at a 3:2 ratio...  which I assume is made up for by the Sodium Channels.

Now you need to add the diagrams of the axons and dendrites.

Anyway, often my fingers type faster than my brain ticks  :-\
 

SteveFish

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Where does our bodies get electricity from?
« Reply #6 on: 11/12/2010 17:46:06 »
Although the Na+/K+ pump does produce a minor charge on cellular membranes because it is moving more positive ions out of the cell than in, it is not really directly responsible for the electrical properties of cells. These pumps are in all cells of the body and the Na+ and K+ gradients they produce are used as an energy source for all kinds of important functions such as maintaining cellular osmotic balance and powering hundreds of types of secondary membrane pumps. Such pumps use the flow down the concentration gradient of Na+ and K+ to separately, sort of, drag molecules through the membrane (symporter) or cause a molecule to be moved across the membrane in the opposite direction (antiporter). For example, there is a Na+/glucose symporter that links import of one Na+ molecule, down its concentration gradient into the cell, to pumping one glucose molecule into the cell. This symporter is in the membrane of an absorptive cell (enterocyte) that, among many other tasks, retrieves glucose from the lumen of the small intestine for use by the body.

As for electrical activity, a K+ leak channel creates most of the membrane potential in all cells, and especially in neurons. The K+ gradient out of the cell leaks a few K+ ions out of the cell and thus leaves an excess of negative ions inside. Both the Na+ and K+ gradients are a primary component of electrical signaling, but this gets very complicated because the nature of excitable membranes and the action potential are not very intuitive from everyday experience, or even a good understanding electricity.
« Last Edit: 11/12/2010 17:51:26 by SteveFish »
 

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Where does our bodies get electricity from?
« Reply #6 on: 11/12/2010 17:46:06 »

 

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