Answer:
Binding of <u>ACh (acetylcholine) </u> to receptors (ligand-gated) on the sarcolemma at the neuromuscular junction is vital for depolarization of the muscle fiber.
Explanation:
It allows acetylcholine to be released into this synapse when an action potential hits a neuromuscular junction. Acetylcholine attaches to the nicotinic receptors localized on the post-synaptic membrane of the muscle fibre's motor end plate, a specialized region.
Hence , the answer is <u>ACh (acetylcholine) .</u>
The quadratus lumborum can perform four actions: Lateral flexion<span> of vertebral column, with ipsilateral contraction. </span>
The endosymbiotic hypothesis concerns the origin of mitochondria and chloroplasts, two organelles contained within various eukaryotic cells. According to this hypothesis, these organelles originated as separate prokaryotic organisms that were taken inside a primordial eukaryotic cell.