Nicotinic receptors are a type of protein found in the nervous system that respond to the neurotransmitter acetylcholine. They play a crucial role in transmitting signals between nerve cells and muscle cells, facilitating communication throughout the body. These receptors are named after nicotine, a compound found in tobacco, which can activate them. These receptors are located in various areas, including the brain and at the neuromuscular junction, where they help control muscle movement. When acetylcholine binds to nicotinic receptors, it triggers a series of events that lead to muscle contraction or the activation of other neurons, influencing many bodily functions.