lihasliittymä

Lihasliittymä refers to the neuromuscular junction, the specialized synapse where a motor neuron communicates with a muscle fiber. This is the critical site for voluntary muscle contraction. When an electrical impulse, or action potential, arrives at the axon terminal of the motor neuron, it triggers the release of neurotransmitters, primarily acetylcholine, into the synaptic cleft. Acetylcholine then diffuses across the cleft and binds to receptors on the sarcolemma, the muscle cell membrane. This binding causes a change in the membrane potential of the muscle fiber, leading to depolarization and the initiation of an action potential that propagates along the muscle fiber. This electrical signal ultimately triggers the release of calcium ions within the muscle cell, which in turn initiates the sliding of actin and myosin filaments, resulting in muscle contraction. The neuromuscular junction is a highly efficient system, ensuring rapid and precise transmission of signals from the nervous system to the muscles. Disruptions at this junction can lead to various neuromuscular disorders.