Lactate Threshold Vs. Anaerobic Threshold

     Hi all.  I thought I knew all of this stuff by now, but I was teaching someone and realized that I still don't fully understand it.  I train by Lactate threshold heart rate (as determined by the 30 minute time trials outlined on this site).  So far it has worked great, no complaints!  I was wondering though, is there a difference between lactate threshold and anaerobic threshold?  Or...are they just two different words for the same thing? 

     The way I have viewed it is that anaerobic threshold is the point of exertion where your muscles begin breaking down glucose anaerobically (without oxygen) and lactic acid begins to accumulate.  This would make the lactate threshold the point at which your body can no longer handle the lactic acid and extreme fatigue sets in (muscles no longer contract smoothly because of the acidic environment, etc.). 

     If I am right, then would anaerobic threshold be the upper end of zone 2 (about 85-91% of your lactate threshold HR)?  This number will change as your lactate threshold HR increases right?  Here is what I am thinking: you can increase your anaerobic threshold by training in zone 2 to increase it and you can increase your lactate threshold HR by training at it or slightly below which teaches your body to deal with the lactic acid for a longer period of time. 

     Please correct me if I am wrong!  This can be kind of confusing stuff and I am trying to teach somwone else the basics of which zones to train in for certain results.  Any thoughts?  Thanks ahead of time.