EVERYDAY SCIENCE

Detailed explanation-1: -Acetylcholine is the neurotransmitter at neuromuscular junctions, at synapses in the ganglia of the visceral motor system, and at a variety of sites within the central nervous system.

Detailed explanation-2: -Acetylcholine is a neurotransmitter at various synapses, nerves, and at the motor end plate of vertebrate muscles. When a nerve impulse arrives at the nerve ending, acetylcholine stored in vesicles, is released, and binds to a postsynaptic receptor, causing depolarization.

Detailed explanation-3: -Ca2+ acts as an intracellular messenger tying the electrical signal of presynaptic depolarization to vesicle release. At fast synapses, Ca2+ enters through clusters of channels near docked synaptic vesicles in active zones.

Detailed explanation-4: -Acetylcholine in the brain alters neuronal excitability, influences synaptic transmission, induces synaptic plasticity and coordinates the firing of groups of neurons.

Detailed explanation-5: -In the somatic nervous system, acetylcholine is used at the neuromuscular junctions, triggering the firing of motor neurons and affecting voluntary movements.