Special Tactics Advanced Skills Training, Hurlburt Field, Fla. Advanced skills training is a 12-to-15-month program for newly assigned combat controller operators. AST produces mission-ready operators for the Air Force and U.S. Special Operations Command. The AST schedule is broken down into four phases: water, ground, employment and full mission profile.
Saltatory Conduction. As in un-myelinated axons, the first action potential in myelinated axons takes place at the initial segment of an axon and is generated by a threshold stimulus from the dendrites and cell body. Subsequent action potentials occur at the nodes of Ranvier, where the Na+ voltage-gated channels are located. Therefore, when nerve impulses travel down a myelinated axon, they appear to jump from node to node - in a process called saltatory conduction. Each nodal action potential is triggered by a threshold stimulus created by passive current from the previous node.
Oder sequence of the impulse conduction through the heart SA Node AV node AV Bundle or Bundle of HIS Right and left bundle branches Purkinje fibers.  When the electrical impulse for muscle contraction is generated, it  travels throughout the muscle of each atrium, causing atrial  contraction. the impulse then travels to the atrioventricular (AV)  node.   according to Medical Assisting-administrative and clinical  procedures with anatomy and physiology.