Terminals
Axons from multipolar, motor neurons terminate on effector structures, such as another neuron, a muscle or a gland. Axons seen here are terminating on skeletal muscle fibers as neuromuscular junctions. Release of the neurotransmitter acetylcholine from these terminals, results in contraction of the muscle fibers. 300x
Neuromuscular junctions >
Contraction of skeletal muscle is initiated by depolarization of the sarcolemma at the neuromuscular junction (NMJ) or motor end plate. NMJs are specialized synapses between axon terminals of multipolar motor neurons and the sarcolemma beneath them. Here, several axons are terminating in NMJs on skeletal muscle fibers. The motor neuron plus all the skeletal muscle fibers it innervates is a motor unit.
Skeletal muscle fibers
Contraction of skeletal muscle is initiated by depolarization of the sarcolemma at the neuromuscular junction (NMJ) or motor end plate. NMJs are specialized synapses between axon terminals of multipolar motor neurons and the sarcolemma beneath them. Here, several axons are terminating in NMJs on skeletal muscle fibers. The motor neuron plus all the skeletal muscle fibers it innervates is a motor unit.
Axons
Contraction of skeletal muscle is initiated by depolarization of the sarcolemma at the neuromuscular junction (NMJ) or motor end plate. NMJs are specialized synapses between axon terminals of multipolar motor neurons and the sarcolemma beneath them. Here, several axons are terminating in NMJs on skeletal muscle fibers. The motor neuron plus all the skeletal muscle fibers it innervates is a motor unit.