motor endplate

(redirected from sole-plate ending)

mo·tor end·plate

the large and complex end formation by which the axon of a motor neuron establishes synaptic contact with a skeletal muscle fiber (cell); several terminal branches of a motor axon end in irregular, club-shaped synaptic end formations, each of which is bedded in its own troughlike depression of the muscle fiber's surface; the postsynaptic membrane, the sarcolemma that forms the bottom of the trough, is greatly increased in surface area by deep infoldings protruding into the underlying cytoplasm of the muscle fiber; the subsynaptic interval between the plasma membrane of the axon terminals and the sarcolemma is filled with an amorphous substance; the trough is closed off toward the surface by the Schwann sheath, which peels away from the axons as the latter enter the trough and thus forms a lid over the trough; the slight bulge of this closure plate corresponds to Doyère eminence.
Synonym(s): sole-plate ending

motor endplate

a large special synaptic contact between motor axons and each skeletal muscle fiber. Each muscle fiber forms one endplate. See also end plate.

mo·tor end·plate

(mō'tŏr end'plāt)
The large and complex end-formation by which the axon of a motor neuron establishes synaptic contact with a striated muscle fiber (cell).

motor endplate

The point of junction of a motor nerve fibre and a muscle fibre. The motor endplate is a modified area of the muscle fibre membrane at which a synapse occurs. A motor nerve axon ending may have up to 50 synaptic knobs (boutons) but a single muscle fibre has only one endplate. The neurotransmitter is acetylcholine.

motor endplate

see ENDPLATE, MOTOR.

motor endplate

term used variously to refer to the specialized region of skeletal muscle fibre membrane lying directly under the terminal of a motor nerve (the nerve's 'footprint' on the muscle, rich in receptors for acetylcholine, to which it responds by depolarization), or to the terminal arborization of the motor nerve. Now most frequently refers to both of these combined in the mammalian form of a neuromuscular junction. See also motor unit.

myoneural junction

; motor endplate synapse of motor neurone terminal fibres with striated muscle fibres

mo·tor end·plate

(mō'tŏr end'plāt)
The large and complex end-formation by which the axon of a motor neuron establishes synaptic contact with a striated muscle fiber (cell).