Which of the following statements about the mechanism of muscle contraction are correct?
A. Acetylcholine is released when the neural signal reaches the motor end plate.
B. Muscle contraction is initiated by a signal sent by CNS via a sensory neuron.
C. During muscle contraction, the isotropic band gets elongated.
D. Repeated activation of the muscle can lead to accumulation of lactic acid.
Which of the following statements about the mechanism of muscle contraction are correct?
A. Acetylcholine is released when the neural signal reaches the motor end plate.
B. Muscle contraction is initiated by a signal sent by CNS via a sensory neuron.
C. During muscle contraction, the isotropic band gets elongated.
D. Repeated activation of the muscle can lead to accumulation of lactic acid.
The correct option is B A and D are correct.
When an impulse arrives at the end plate of an axon, the vesicles therein release acetylcholine, which diffuses across the nerve-muscle gap, binds to receptors on the sarcolemma and increases the permeability of sarcolemma to sodium ions. This causes depolarisation of the sarcolemma and results in the contraction of the muscle fibre.
Repeated activation of the muscle decreases the supply of oxygen to the muscle tissues, thereby causing accumulation of lactic acid.
During muscle contraction, the isotropic band gets shortened.
A and D are correct.
When an impulse arrives at the end plate of an axon, the vesicles therein release acetylcholine, which diffuses across the nerve-muscle gap, binds to receptors on the sarcolemma and increases the permeability of sarcolemma to sodium ions. This causes depolarisation of the sarcolemma and results in the contraction of the muscle fibre.
Repeated activation of the muscle decreases the supply of oxygen to the muscle tissues, thereby causing accumulation of lactic acid.
During muscle contraction, the isotropic band gets shortened.
