The red nucleus is a small, round structure located in the midbrain, specifically within the mesencephalon. It plays a crucial role in motor coordination and is involved in the control of limb movements. The red nucleus receives input from the cerebellum and the cortex, helping to integrate and relay motor signals to the spinal cord. This nucleus is named for its reddish appearance, which is due to the presence of iron-containing pigments. It is part of the extrapyramidal system, which helps regulate involuntary movements and posture. Dysfunction in the red nucleus can lead to motor disorders, highlighting its importance in the nervous system.