MEDICAL PHYSIOLOGY

Detailed explanation-1: -The neurotransmitter acetylcholine diffuses across the synaptic cleft, causing the depolarization of the sarcolemma. The depolarization of the sarcolemma stimulates the sarcoplasmic reticulum to release Ca2+, which causes the muscle to contract.

Detailed explanation-2: -The axon terminal rests within a primary depression of sarcolemma, the primary cleft, and contains numerous small vesicles that contain acetylcholine (ACh), the neurotransmitter for excitation of skeletal myofibers.

Detailed explanation-3: -Binding with receptors can have different effects depending on the area of the nervous system that acetylcholine is affecting. Acetylcholine can cause an action potential, or it could activate a secondary messenger system.

Detailed explanation-4: -The chemical message, a neurotransmitter called acetylcholine, binds to receptors on the outside of the muscle fiber. That starts a chemical reaction within the muscle.

Detailed explanation-5: -As ACh binds at the motor end plate, this depolarization is called an end-plate potential. The depolarization then spreads along the sarcolemma, creating an action potential as sodium channels adjacent to the initial depolarization site sense the change in voltage and open.