Neuromuscular Transmission: Motor End Plate Structure

Motor End Plate (MEP) Structure

• Consists of a motor nerve, synaptic cleft, and muscle fiber
• Motor Nerve:
  • Loses its myelin sheath and branches into multiple sole foots to increase surface area
  • Sole foots contain mitochondria, acetylcholine vesicles, and dense bars
  • Covered by neurolemma, which continues with the sarcolemma of muscle fibers

Synaptic Cleft:

• Distance of 200-300 Å between the nerve and muscle fiber
• Releases acetylcholine (Ach) from the nerve to stimulate the muscle
• Contains cholinesterase enzyme, which hydrolyzes Ach

Muscle Fiber:

• Membrane has invaginations called synaptic gutters and subneural clefts to increase surface area for Ach effect

Neuromuscular Innervation:

Motor Unit:

• Consists of one anterior horn cell (AHC), its axon, and muscle fibers (3-300) supplied by this axon
• Obeys the all-or-none law

Motor Pool:

• Comprises all AHCs, nerve, and skeletal muscle supplied by it

This quiz covers the structure and function of the motor end plate, including the motor nerve and synaptic cleft. Learn about the formation of the motor end plate and its role in neuromuscular transmission.