Latent Period, Contraction Phase And Relaxation Phase Of Single Muscle Twitch Flashcards
What are the three main phases of a single muscle twitch?
The latent period, contraction phase, and relaxation phase.
True or False: The latent period is the time between the stimulus and the beginning of muscle contraction.
True.
What occurs during the contraction phase of a muscle twitch?
Muscle fibers shorten and generate force.
Fill in the blank: The __________ period is characterized by the muscle returning to its resting state.
relaxation
How long does the latent period typically last?
A few milliseconds.
What physiological processes occur during the latent period?
Calcium ions are released and cross-bridge cycling is initiated.
What is the primary change in muscle length during the contraction phase?
Muscle length decreases as it contracts.
True or False: The relaxation phase involves the reuptake of calcium ions into the sarcoplasmic reticulum.
True.
What is the effect of muscle fatigue on the phases of a muscle twitch?
Muscle fatigue can prolong the relaxation phase and reduce contraction strength.
Multiple Choice: Which phase follows the contraction phase? A) Latent B) Relaxation C) Excitation
B) Relaxation.
What is the role of ATP during the relaxation phase?
ATP is required for the active transport of calcium back into the sarcoplasmic reticulum.
Fill in the blank: The duration of the contraction phase is generally __________ than the latent period.
longer
True or False: The speed of contraction varies between different muscle types.
True.
What happens to muscle tension during the relaxation phase?
Muscle tension decreases as the muscle fibers lengthen.
Define ‘twitch’ in the context of muscle physiology.
A twitch is a single, quick contraction and relaxation of a muscle fiber.
What initiates the contraction phase of a muscle twitch?
The binding of calcium ions to troponin, exposing myosin binding sites.
Multiple Choice: Which phase has the longest duration? A) Latent B) Contraction C) Relaxation
C) Relaxation.
What is the typical duration of the contraction phase in skeletal muscle?
15 to 100 milliseconds.
Fill in the blank: During the relaxation phase, the muscle returns to its __________ length.
resting
True or False: The latent period is influenced by the speed of the stimulus.
True.
What is the significance of the latent period in muscle contraction?
It allows time for calcium release and cross-bridge formation before contraction begins.
Describe how the relaxation phase affects muscle responsiveness.
It allows the muscle to recover and become responsive to subsequent stimuli.
What happens to the muscle fibers during the contraction phase at the molecular level?
Myosin heads bind to actin and pull, causing the filaments to slide past each other.
Multiple Choice: Which of the following is NOT a phase of a muscle twitch? A) Latent B) Contraction C) Refractory
C) Refractory.
What role does the sarcoplasmic reticulum play during the contraction and relaxation phases?
It stores and releases calcium ions essential for muscle contraction and relaxation.
