Latent period:
- It is the period from the point of stimulus to the point of onset of contraction.
Contraction period:
- It is the period between the point of onset of contraction to the point that corresponds to the peak of contraction.
Relaxation period:
- It is the period from the peak of contraction to the end of relaxation.
Q.1 What is the cause for Latent Period?
The latent period is due to a chain of events
- The time taken by the APs to travel from the point of stimulation to the motor endplates.
- Release of acetylcholine, sodium influx, and generation of muscle action potential which leads to contraction.
- Viscosity of the muscle.
- Inertia of the lever system which has to be overcome before contraction can be recorded.
Q.2 What are the factors that determine the height of the
simple muscle curve?
- Strength of stimulus
- Initial length of muscle fibers (preload)
- Type of load
- Temperature
- Type of muscle fibers in the muscle
- Inertia of the lever system
- Magnification of the lever