Ex. 11 Muscle Physiology Graded A+

Ex. 11 Muscle Physiology Graded A+ A skeletal muscle is stimulated to contract by what structure? ️️Nerve What chemical crosses the synapse, causing a muscle to contract? ️️Acetylcholine (Ach) Where is calcium released to cause muscle contraction? ️️Sarcoplasmic reticulum What are the two types of myofilaments? ️️Actin and myosin Does a single muscle fiber or an entire muscle contract by a all-or-none response? ️️Single muscle fiber Name the first phase after a stimulus in a muscle contraction ️️Lag phase Define Subthreshold stimulus ️️Type of stimulus that will not elicit a response in the muscle What happens to the strength of contraction during wave summation? ️️The strength of contraction increases greatly Describe Tetanus ️️continuous smooth muscle contraction brought about by rapid, sequential stimuli What is maximus recruitment? ️️Stimulus needed to trigger all muscle fibers in a muscle to contract. How do tetanus and twitch, as demostrated in the lab, correlate to human muscle contraction? Which one is more reflective of human muscle response? why? ️️Human muscles do not normally respond by singular contractions seen as twitches. Human muscle contraction occurs by numerous firings demonstrated as tetanic contractions. Explain a muscle spasm in terms of recruitment of muscle fibers ️️Recruitment of spontaneous muscle fibers How does your favored arm compare with your weak arm in terms of electrical activity? ️️favored arm should show greater electrical activity How does the muscle respond to weight when it is first contracting versus when it is fatigued? ️️muscle shows smooth contraction when first contracting when muscle is fatigued the contractions become more spasmodic. As an athlete "warms up" before exercising, the muscles increase in temperature, What effect does this have on various phases of muscle contraction? ️️Increase in temperature produces more rapid enzymatic reactions, therefore the muscle responds faster and w