13Papillae in tongueLingual taste buds sit on lateral borders of raised papillae. They are classified as:Fungiform: at tip & sides of tongueCircumvallate: just in front of terminal sulcusFoliate: at posterior lateral margins of tongueFiliform: centre of tongue, have no taste buds
21Lower Limit of Nasopharynx Lower border of soft palate or Junction b/w hard & soft palateOropharynxTip of epiglottis or Body of hyoid bone or Base of valleculaHypopharynxLower border of cricoid orLower border of C6 vertebra
25Nasopharyngeal Isthmus Separates nasopharynx from oropharynxBounded anteriorly by soft palate & posteriorlyby mucosal ridge on nasopharyngeal wall calledPassavant’s ridge (due to palatopharyngeus)Closure of this isthmus prevents nasalregurgitation & nasal intonation
31Waldeyer's tonsillar ring Vertically oriented, sub-epithelial lymphoid tissue ring located in pharynx, thought to function as a barrier to infection in first few years of life. Named after nineteenth century German anatomist Heinrich Wilhelm Gottfried von Waldeyer-Hartz.
43Killian’s DehiscenceTriangular weak area between thyropharyngeus & cricopharyngeus part of inferior constrictorMucosa herniates through it to form hypo-pharyngeal pouch (Zenker’s diverticulum)Perforation occurs here during forceful oesophagoscopy (gateway of tears)
70Fibrous coat (adventitia) Layer of loose, supportive fibrous tissueConducts major vessels & nerves longitudinallyA serosa formed by visceral peritoneum replaces adventitia of intra-abdominal segment of oesophagus