<prompt> Retropharyngeal space extends from base of skull to:Hyoid boneBifurcation of tracheaAngle of mandibleCricoid cartilage  <response>: Retropharyngeal space: It lies behind the pharynxbetween the buccopharyngeal fascia covering pharyngeal constrictor muscles and the pre vertebral fascia.It extendsfrom the base of skull to the bifurcation of trachea.Thespace is divided into two lateral compartments spaces ofGillette by a fibrous raphe.Each lateral spacecontains retropharyngeal nodes which usually disappear at3-4 years of age.Parapharyngeal space communicates withthe retropharyngeal space.Infection of retropharyngealspace can pass down behind the oesophagus into themediastinum . 