4.3
What term refers to a smooth, sustained contraction? muscle twitch isometric contraction complete tetanus isotonic contraction
complete tetanus
What enzyme breaks down acetylcholine into acetic acid and choline to prevent continued contraction of the muscle fiber? acetylcholinesterase potassium ions calcium ions cross bridges sarcoplasmic reticulum
acetylcholinesterase
A smooth, sustained contraction, with no evidence of relaxation, is called ________. fused, or complete, tetanus summing of contractions a twitch unfused, or incomplete, tetanus
fused, or complete, tetanus
Skeletal muscle, as a whole, can generate different amounts of force, and different degrees of shortening, in response to stimuli. What is this concept called? fused, or complete, tetanus graded response action potential twitch incomplete, or unfused, tetanus
graded response
What term describes the ability of a muscle to vary its degree of shortening to generate the strength needed to lift a 5 lb weight, a 7 lb weight, and finally a 10 lb weight? twitch isometric contractions isotonic contractions graded responses
graded responses
A skeletal muscle twitch differs from a tetanic contraction in that ________. the tetanic contraction is considered abnormal, while the twitch is a normal muscle response the muscle twitch is prolonged and continuous while a tetanic contraction is brief and "jerky" the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous the muscle twitch occurs only in small muscles while a tetanic contraction occurs in large muscle groups the tetanic contraction is caused by a single stimulus, while the twitch is caused by very rapid multiple stimuli
the muscle twitch is a brief and "jerky" movement, while the tetanic contraction is prolonged and continuous