Anesthesia Technician Practice Exam

What is the primary depolarizing muscle relaxant used in anesthesia?

1. Rocuronium

2. Vecuronium

3. Succinylcholine

4. Atacurium

The correct answer is: Succinylcholine

Succinylcholine is recognized as the primary depolarizing muscle relaxant used in anesthesia due to its unique mechanism of action. It simulates the action of acetylcholine, binding to the neuromuscular receptors at the motor end plate and causing an initial depolarization of the muscle membrane. This leads to a brief period of muscle contraction followed by relaxation. The rapid onset and short duration of action make succinylcholine particularly valuable in situations that require quick intubation or relaxation of skeletal muscles for surgical procedures. Other muscle relaxants listed, such as rocuronium, vecuronium, and atracurium, are classified as non-depolarizing agents. These substances work by competitively blocking the binding of acetylcholine to the receptors, preventing muscle contraction. They do not cause the initial depolarization or fasciculation associated with succinylcholine and have varied durations of action and onset times that are typically longer than that of succinylcholine. Therefore, while these alternatives are important and commonly used in practice, they do not provide the same immediate effect that is characteristic of the depolarizing muscle relaxant, succinylcholine.