Jim Bob is at the dentist to have a cavity filled. He is worried about pain, but his dentist assures him that he would feel no pain because he is going to administer a shot of lidocaine. Lidocaine is a sodium channel blocker. Define what a sodium blocker does and how it effects the transmission of pain sensations to the brain which would explain why Jim Bob will "feel no pain". What other functions besides sensory might be affected? Think about what happens when you get a local anesthetic at the dentist.