As an anesthesiologist, Dr. Richard Rust of Indianapolis, Indiana, draws on 20 years of professional experience. Dr. Richard Rust comes to his work with a detailed knowledge of anesthetic drugs and how they work.
Designed to numb sensation in a particular area, local anesthetic interrupts the transmission of pain signals to the brain. It does this by interfering with the function of the sodium channel, an ion transmission channel in the nerve cell membrane.
A nerve cell has selective ion permeability, meaning that a series of channels pass through the lipid membrane, each allowing a certain type of protein ion to pass. At rest, the potassium channels are open while the gates for sodium are closed, leading to a negative charge inside the cell.
When a pain stimulus causes excitement of the nerve cell the sodium channels open, allowing for sodium ions to pass through it and to change its charge to positive. This in turn causes an action potential to pass along the nerve fibre which, when it reaches the brain, makes the patient feel pain. Medical scientists believe that local anesthetic blocks the sodium channel and prevents the passage of positive ions, thus interrupting this action potential. Therefore, although there is a pain stimulus, such as that of localized surgery, the patient does not feel any discomfort.
Designed to numb sensation in a particular area, local anesthetic interrupts the transmission of pain signals to the brain. It does this by interfering with the function of the sodium channel, an ion transmission channel in the nerve cell membrane.
A nerve cell has selective ion permeability, meaning that a series of channels pass through the lipid membrane, each allowing a certain type of protein ion to pass. At rest, the potassium channels are open while the gates for sodium are closed, leading to a negative charge inside the cell.
When a pain stimulus causes excitement of the nerve cell the sodium channels open, allowing for sodium ions to pass through it and to change its charge to positive. This in turn causes an action potential to pass along the nerve fibre which, when it reaches the brain, makes the patient feel pain. Medical scientists believe that local anesthetic blocks the sodium channel and prevents the passage of positive ions, thus interrupting this action potential. Therefore, although there is a pain stimulus, such as that of localized surgery, the patient does not feel any discomfort.