Muscle metabolism Flashcards
one motor neuron and all the muscle fibers it intervates or supples
motor unit
Motor unit’s response to a single action potential of it motor neuron, contracts quickly the relaxes
muscle twitch
No muscle tension, events of e-c coupling
Latent period
tension increases, cross bridge cycling
Contraction
Ca reentry into SR, tension declines
relaxation
Muscle length changes and moves load
isotonic contraction
muscle shortens and does work
concentric contraction
muscle generates force as lengthens
eccentric contraction
Tension to muscle’s peak tension-producing capacity. more load greater than the force the muscle is able to develop
Isometric contraction
Many muscle fibers in motor unit, vary strengths of contraction for different demands, proper control of skeletal movement
Graded muscle responses
Two stimuli are received by muscle in rapid succession
Wave (temporal) summation
Degree of wave summation becomes greater progressing to a sustained contraction- another stimulus applied before muscle relaxes
Unfused (incomplete) tetanus
If stimuli frequency increases, muscle tension reacher max, smooth sustained contraction plateau, no relaxion
Fused (complete) tetanus
Stimulus is sent to more muscle fibers, leading to more precise control
Recruitment (multiple motor unit summation)
No contraction, not strong stimilus
Subthreshold stimulus
First observable contraction, not strong stimulus
Threshold stimulus
Max contractile force, strongest stimulus
Maximal stimulus
glycolysis and lactic acid formation, ATP generated from breakdown of glucose from blood or glycogen stored in muscle, no oxygen, 2 ATP/ glucose
Anaerobic pathway
Glucose broken down into 2 pyruvic acid, releasing ATP
Glycolysis
In mitochondria, requires oxygen, chemical reactions that break bonds of fuel molecules and release energy to make ATP
Aerobic respiration
Length of time muscle contracts using aerobic pathways
Aerobic endurance
Muscle metabolism converts to anaerobic pathway
Anaerobic threshold
