Muscle Innervation

1
Muscle Innervation

• Skeletal muscles are acted upon by somatic motor
  neurons (neurons that take thought)
• Motor unit axon terminal branches of the neuron
  and the muscle fibers that they act on
• Motor units can be small or large depending on
  type of movement, gross, fine

2
Neuromuscular Junction

• Synapse the connection between nerve and target
  cell (neuromuscular junction)
• Synaptic knob end of neuron that rests next to
  muscle fiber
• Synaptic cleft the gap between the knob and
  muscle fiber
• Acetylcholine (ACh) A chemical produced by
  neuron, acts as neurotransmitter

3
Neuromuscular Junction

• Synaptic vesicles organelle sacks that store ACh
• ACh receptors bind to ACh
• Basal lamina a thin layer of collagen and
  proteins at cover fiber and fills synaptic cleft
• Acetylcholinesterase (AChE) produced by lamina
  in cleft. Brakes down ACh so muscles can relax