The stellate ganglion is a collection of nerve cells located in the neck, specifically at the level of the sixth and seventh cervical vertebrae. It is part of the sympathetic nervous system, which helps regulate involuntary bodily functions such as heart rate and blood pressure. The stellate ganglion plays a crucial role in the body's response to stress and can influence various physiological processes. This ganglion is formed by the fusion of the inferior cervical ganglion and the first thoracic ganglion. It sends nerve fibers to the head, neck, and upper limbs, affecting blood flow and sweating in these areas. Understanding the function of the stellate ganglion is important in medical fields, particularly in treating conditions like complex regional pain syndrome and Raynaud's phenomenon.