Acetylcholine receptors are specialized proteins located on the surface of cells that respond to the neurotransmitter acetylcholine. They play a crucial role in transmitting signals between nerve cells and muscle cells, facilitating communication in the nervous system. There are two main types of acetylcholine receptors: nicotinic and muscarinic, each with distinct functions and locations in the body. Nicotinic receptors are primarily found at the neuromuscular junction, where they help trigger muscle contraction, while muscarinic receptors are involved in various functions, including heart rate regulation and glandular secretions. Both types are essential for maintaining proper physiological processes.