Complex sentence: The subcommissural organ (SCO) is a small secretory organ located near the anterior entrance of the Sylvian Aqueduct and at the midline roof of the 3rd Ventricle.
Split into simpler sentences: The subcommissural organ (SCO) is a small secretory organ located near the anterior entrance of the Sylvian Aqueduct. It is also placed at the midline roof of the 3rd Ventricle.