1. Diego really had a strain, but mistook it for a sprain. He thought he had a sprain, which is a stretch and/or tear of a ligament that joins the end of one bone with another in a joint. However, he had an injury of his muscle and/or tendon, which are fibrous cords of tissue that attach muscles to bone. That is why he was confused, saying that his joints were not in pain.
2. When a muscle is worked against what it is not accustomed to do, which in this case would be lifting heavy weights, it will begin to adapt to the resistance. There are two possibilities. Hypertrophy could have happened; it is where individual muscle fibers become bigger, making the whole muscle bigger. Also, hyperplasia could have occurred, which is the dividing of a muscle fiber. When the fibers divide, the entire muscle also becomes larger.
3. When an organism dies, its muscles are in a contracted state, also known as rigor mortis, for a brief period of time. This happens because ATP is no longer produced to break bonds between the thick and thin filaments, which allow the natural movement of muscle tissue. After about 3 days, rigor mortis is past its peak, so the coroner would not have as much difficulty.
4. Chemical A would be the better muscle relaxant. Since muscle relies on Ach as a stimulant, chemical A would hinder communication between the muscle cell and neuron. The muscle would not be able to contract. Chemical B would cause further contraction of the muscle because calcium is needed to