Lab 7: Exercise 11

motor neuron/nerve

a skeletal muscle is stimulated to contract by what structure

acetylcholine (ACh)

chemical that crosses the synapse, causing a muscle to contract

sacroplasmic reticulum

where calcium is released inside the muscle fiber to cause muscle contraction

actin and myosin

two types of myofilaments found in muscle cells that cause muscle contraction

single muscle fiber

contracts by an all or none response

lag phase

first phase after a muscle in a muscle contraction

subthreshold stimulus

type of stimulus that will not elicit a response in the muscle

increase

what happens to the strength of contraction during wave stimulation

tetanus

repeated muscle contracts sent to muscle

maximum recruitment

lowest voltage stimulus to which all of the muscle fibers are stimulated

tetanus is more reflective of human muscle contraction due to temporal sumation

how does the tetanus and twitch, correlate to human muscle contraction, which is more reflective of human muscle response

spontaneous muscle fibers

muscle spasm in terms of recruitment of muscle fibers

comparing favored arm with weak arm in terms of electrical activity

favored arm shows greater electrical activity and greater motor unit recruitment

difference in muscle response to weight when first contracting verus to when it is fatigued

Muscle contractions are smoother when first contracting. When the muscle is fatigued, the contraction becomes 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

more rapid response reaction which increase response and force, muscles contract faster and more forcefully

increases

what happens to the strength of contraction during wave stimulation

tetanus

continuous smooth contraction of muscle brought about by rapid, sequential stimuli

muscle spasm

spontaneous recruitment of numerous muscle fibers

lag phase

phase immediately follows the stimulus in a muscle twitch