1. The adrenal medulla stems from embryonic neuro-ectoderm.
2. Comprising rounded clusters of large granular cells known as chromaffin cells, it consists of modified post-ganglionic cells from the sympathetic nervous system.
3. These cells maintain connections with preganglionic fibers of the sympathetic nervous system.
4. Consequently, the adrenal medulla serves as a continuation of the sympathetic nervous system.
5. In this manner, the adrenal medulla and sympathetic nervous system operate as a tightly integrated system.