What triggers the opening of Na+/K+ channels in the motor end plate?
Understand the Problem
The question is inquiring about the activation mechanism of Na+/K+ channels specifically at the motor end plate, which is related to neurophysiology. It requires knowledge of the physiological processes involved in muscle contraction and neurotransmission.
Answer
Acetylcholine binds to receptors, triggering Na+/K+ channel opening.
The opening of Na+/K+ channels in the motor end plate is triggered by the binding of the neurotransmitter acetylcholine (ACh) to receptors on the muscle surface.
Answer for screen readers
The opening of Na+/K+ channels in the motor end plate is triggered by the binding of the neurotransmitter acetylcholine (ACh) to receptors on the muscle surface.
More Information
When acetylcholine is released into the synaptic cleft, it binds to nicotinic acetylcholine receptors on the motor end plate. This causes a conformational change in the receptor, allowing the channel to open and Na+ ions to flow into the muscle cell and K+ ions to flow out, depolarizing the membrane.
Tips
A common mistake is assuming direct electrical stimulation opens these channels, rather than neurotransmitter binding.
Sources
- Neural Stimulation of Muscle Contraction | Biology for Majors II - courses.lumenlearning.com
- Physiology, Action Potential - StatPearls - NCBI Bookshelf - ncbi.nlm.nih.gov
- Synaptic Transmission at the Skeletal Neuromuscular Junction - nba.uth.tmc.edu
