Describe all of the events in excitation-contraction coupling in the following paragraphs; before you can see other answers, you must write your own post; make sure you write your answer in your own words:
A. Excitation, part 1: Explain what happens at the neuromuscular junction (NMJ). (see figure 10.10, 4 pts)
- What is the role of the motor neuron?
- What is the role of calcium in the motor neuron?
- What membrane transport processes happen?
- What is the role of the acetylcholine (ACh) receptor in the skeletal muscle cell?
B. Excitation, part 2: What happens in a muscle cell after the events in the NMJ? (see figure 10.11, 4 pts)
- What immediately happens as a result of ACh binding to the ACh receptor?
- Revisiting the discussion board from chapter 12 – what is the electrical event that occurs – what was the term we used in chapter 12? Explain how it works.
- Explain how the sarcolemma is similar to an axon. What happens along the surface of the sarcolemma?
- What happens to the sarcoplasmic reticulum that allows it to release Ca++ into the cytosol?
C. What happens at a sarcomere after Ca++ becomes available? Describe the steps of the contraction cycle and include the functions of all proteins in the thin and thick filaments. (see figure 10.13, 7 pts)
Write 3 separate paragraphs for parts A, B & C (one paragraph per question block).
Check your word count – you should be in the ballpark of 400 words. If you are significantly under that number, you probably need to add more details.
