Appendix of the laryngeal ventricle

The appendix of the laryngeal ventricle (also the laryngeal saccule, laryngeal pouch, or Hilton's pouch) is a diverticulum (membranous sac) which extends vertically from the ventricle of the larynx. It runs between the vestibular fold, thyroarytenoid muscle, and thyroid cartilage, and is conical, bending slightly backward. It is covered in roughly 70 mucous glands. The muscles surrounding the appendix compress it till a secretion comes out and lubricates the vocal folds.