Here is some more information to help you understand why a, c, and e are the correct answers, and why b and d are incorrect. a. The basic neural adaptation is increasing the activation of the agonist muscle. Calling more motor units of that muscle into play results in increased force production. As your nervous system "learns," it's able to recruit more motor units that can contribute to the specific movement. c. Research in animals has shown that the area of the neuromuscular junction can increase, meaning that there are more receptors for acetylcholine on the sarcolemma. This interesting adaptation means that the signal to the muscle cell can be improved. e. Synergist muscles are the agonist's helper muscles. The force the synergists generate works in the same direction as the agonist. Thus, there is an additive effect. The nervous system adapts by calling more motor units in the synergist muscles into play to increase total force output. b. Remember that synchronicity means that all of the fibers will fire at the same time. Asynchronicity is the opposite. The more motor units firing at the same time, the more force; therefore, one neural adaptation is to have synchronous firing of motor units. This is another neural adaptation. d. Keep in mind that the antagonist works in opposition to the agonist. To figure out the total force applied to an external resistance such as a weight, you must subtract the force generated by the antagonist from the force generated by the agonist and synergist muscles. Fortunately, the nervous system adapts to resistance training by decreasing antagonist activity, resulting in a greater sum of forces from the agonist and synergist muscles. Click Next to continue.