PhysioEx Activity 2 fully solved graded A+ 2023

PhysioEx Activity 2 fully solved graded A+ 20231. Define the terms skeletal muscle fiber, motor unit, skeletal muscle twitch, electrical stimulus, and latent period - correct answer Skeletal muscle fibers: a long cylindrical cell with multiple oval nuclei just beneath its sarcolemma. Motor unit: consists of a motor neuron and all of the muscle cells it stimulates. Skeletal muscle twitch: a single stimulated contraction of whole skeletal muscle. Electrical stimulus: the elicitatin of muscle contraction using electrical impulses. Latent period: the period of time that elapses between the generation of an action potential in a muscle cell and the start of muscle contraction 2. What is the role of acetylcholine in a skeletal muscle contraction? - correct answer Acetylcholine binds to receptors in the motor end plate, initiating a change in ion permeability that results in the end-plate potential. 3. Describe the process of excitation-contraction coupling in skeletal muscle fibers. - correct answer Excitation-contraction coupling is the release of calcium which binds to troponin, removing the blocking action of tropomyosin so that myosin can bind to actin. 4. Describe the three phases of a skeletal muscle twitch. - correct answer Latent period is the time preparing for contraction. Contraction is when muscle tension peaks. The relaxation period is at the end of muscle contraction.