The term medial nuclear group of the anterior horn refers to a group of cells, posteromedial and anteromedial, in the spinal cord. The posteromedial group is more distinct in the cervical enlargement and the lumbosacral enlargement and may be absent in the sacral segments. The anteromedial group is more distinct in the cervical segments 1, 2 and 4, thoracic segments 1 and 2, lumbar segments 3 and 4, and sacral segments 2 and 3 ( Carpenter-1983 ).