Local anesthetics inhibit nerve conduction in a reversible manner without altering the nerve. The inhibition appears rapidly and for a longer or shorter duration depending on the products and the concentrations used. The extent of the territory rendered insensitive to pain depends on the modes of administration of the local anesthetic, either at the level of the nerve endings, or at the level of a nervous trunk, for example.
They act at the level of the neuronal membrane by interfering with the process of excitation and conduction. The anesthetic crosses the axon membrane, rich in lipids, in the form of base before taking up a cationic form on the internal face of the neuron where the pH is more acidic.
At this level, there is a blockage of nerve conduction by decreasing the membrane permeability to sodium ions that occurs during the depolarization phase. As the progression of the anesthetic action along the nerve increases, the threshold of excitability increases and the conduction time increases. This is completely blocked from a certain concentration of local anesthetic.
The nerve fibers are unequally sensitive to the action of local anesthetics: they disappear in order: the painful, thermal, tactile sensations.
It's the same reasoning as why insurance gives better deals to people of greater age.. They are seen to have more experience and be more "mature " to drive safer if you have more years driving your insurance goes down.. same concept
Answer:
A
Explanation:
Exercise is important for your body to function and will make you much healthier when you are older
