General Anesthesia. How far down does the tube go into the throat? Will I get knocked out right away?

With general anesthesia, patients can be given in endotracheal tube which is placed below the vocal cords, or a laryngeal mask airway( LMA) and that is placed above the vocal cords. Patients are initially put to sleep through the IV,  and once patients are completely asleep then the tube is inserted. With general anesthesia there's no recollection of the placement of the tube or the surgery itself. Make sure that you have a board-certified physician anesthesiologist to perform your anesthesia. In addition make sure the surgery center where the procedure is performed is licensed, accredited or certified. 

I recommend you don't focus on the tube.  One of the main goals of anesthesiologists is for you to have a quality total experience.  In general, you will most likely get some medication (often through your IV) to make you very relaxed and forgetful.  That way, when the tube goes in and when it comes out are periods of your treatment that you won't remember.  The tube goes in just far enough to protect your airway while you are "asleep".  Your anesthesiologist will do multiple checks to ensure that it is in the right place and keeps you safe.  Wish you all the best.Garrett Wirth, MD, MS, FACS