Question

When do muscle fibres contract?

Answer 1

Muscle fibres:

1. The muscle tissues of the body form the contractile tissue and are made of muscle cells.
2. The cells are elongated and large-sized, so they are called muscle fibres.
3. The contraction of muscles is caused due to stimulation.

Contraction of muscle:

1. Muscle contraction is triggered when an action potential travels along a nerve to the muscle
2. Muscle contraction begins when the nervous system sends out a signal. The signal, an impulse called an action potential, travels through a type of nerve cell called a motor neuron.
3. The neuromuscular junction is the name for where the motor neuron reaches the muscle cell. Skeletal muscle tissue is made up of cells called muscle fibers. When a signal from the nervous system reaches the neuromuscular junction, a chemical message is emitted by the motor neuron.
4. The chemical messenger, a neurotransmitter called acetylcholine, binds to receptors on the outside of the muscle fiber. This causes a chemical reaction in the muscle.
5. Acetylcholine is released and binds to receptors on muscle membranes
6. Muscle fibers relax when signals from the nervous system are gone