Rami communicantes are a series of nerve fibers that connect the spinal nerves to the sympathetic ganglia. These nerve fibers are important for the sympathetic division of the autonomic nervous system. Synonyms for the term rami communicantes include communicating branches, sympathetic roots, and nerve loops. These terms refer to the same set of nerve fibers that transfer information between the spinal nerves and the sympathetic ganglia. Rami communicantes are responsible for the regulation of many involuntary processes in the body, such as heart rate, breathing, and digestion. Understanding the importance of these nerve fibers is crucial for the treatment of many medical conditions.