Which of the following statements accurately describes the pattern of recruitment in a muscle when performing a maximal force contraction? A. A few small and medium motor units will be recruited; if that's not enough, then all of them will be. B. Small motor units are recruited first, then medium, and then the largest to reach maximum force.

2. We discussed how muscle spindles allow for precision of movement as a muscle lengthens, and particular muscles which require more precise movements will contain more spindles. In addition to this precision control over muscle length, there are other differences between muscles which enable more precision in how much force is generated. Consider the two graphs below which depict force generated by two different muscles as additional motor units are recruited. Force Muscle A Load Force Muscle B Load a) Describe why the first steps for a low force contraction in both muscles are smaller than the later ones in the context of motor units and force production.

Put the following events of excitation-contraction coupling in the order in which they occur.1. Excitation2. Sarcomere shortening3. Generation of muscle tension4. Neural control5. Contraction cycle begins6. Release of calcium ions Group of answer choices 1,2,5,6,3,4 4,1,5,2,6,3 6,1,4,2,5,3 4,1,6,5,2,3 1,4,6,2,5,3

With regard to muscle contraction, which of the following is an INCORRECT statement with regard to the interactions of filaments that occur in the sarcomere? A. When muscles are relaxed tropomyosin blocks binding sites on actin subunits, which keeps cross-bridges from forming. B. The myosin heads conduct a power stroke motion to slide when bound to actin, to move the "thin" filaments towards the center of the sarcomere. C. During contraction, actin subunits are removed from the ends of the "thin" filaments to shorten actin polymers, thus reducing the length of the sarcomere. D. "Thick" filaments are anchored at the M-line, while "thin" filaments are anchored at the Z-line. E. Numerous myosin heads engage with the actin filaments simultaneously, such that there is no back-slipping during the contraction process.