General Anesthesia

[Deslaar]

I have a few questions. [:)]

Could someone explain to me the pharmacological and biological mechanisms involved in general anesthesia?

It would appear that under general anesthesia consciousness is completely "turned off". To what extent is brain function reduced. Do general anesthetics target particular areas of the brain?

Thanks in advance.

BTW and on a philosophical note, is being under a general anesthetic indistinguishable from and, in a temporal sense, equivalent to death?

[spacemanspiff]

so what i gleamed from various sources it that it is not an extemly well understood thing. at least not at the cellular level.

I read of some theory that it affects the proteins in neurons and that is what changes your level of consciousness.

under anesthesia, individual protein molecules in the brain somehow become larger than normal and that shrinking them rouses a person awake again.

[nevagil]

It's been a decade since my neurology class but I have been hit on the head with a 2x4 since then.

I'm waiting for an someone in that field to reply but I suspect that under gen. A that some of the brain is still workin like some of the brain sending the vagus nerve impluses to keep the heart beating.
Other involuntary body functions probably function too, although maybe a respirator is needed for the lungs, I don't know.
Therefore I don't think general anest. is much like being dead.

Maybe the nerve connections that deliver pain, temperature, etc are interrupted.

gilnv of www.surrealcity.com

[Deslaar]

Thanks for the replies but I think you'll agree that my questions haven't really been answered. Anyone else? Please....I'm intrigued.

[Another God]

i have no idea really, but I do know that ppll are researching snake venoms in the hope of finding more effective anaesthetics. perhaps searching for explanations on how venoms work will help explain how anaesthetics work.

[damgo]

There are different levels of anaesthesia -- at the deepest, most brain function is blocked, to the extent that respiration must be artificially maintained; at the lightest, a patient might be conscious enough to talk back to doctors, though long-term memory is typically one of the first things to go.

Not sure how they work, or even if they all work in the same way -- IIRC traditional anaesthetics like ether work quite differently from some of the new stuff, like benzodiazepine-opioid anaesthesia.

[Tyger]

but don't quote me on this. GA's are usually simple oil soluble molecules like ether or cyclopropane and they work by by being absorbed into the mylin sheath of the nerve cells which generate impulses by transfering ions. The GA make the sheath permeable to ions, reducing the nerve cell function.

[Ivan Seeking]

Here is one explanation:

Sci Am ask the experts - General Anesthesia (http://www.sciam.com/article.cfm?articleID=0006AD71-56C7-1C75-9B81809EC588EF21&pageNumber=1&catID=4)