You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is In direct laryngoscopy which of the following cannot be visualized and explain in detail?
Following structures are examined serially: Base of tongue, right and left valleculae, epiglottis, (its tip, lingual and laryngeal surfaces), right and left pyriform sinuses,aryepiglottic folds, arytenoids, postcricoid region, both false cords, anterior and posterior commissure, right and left ventricles, right and left vocal cords and subglottic area. Mobility of vocal cords should also be observed. Ref: Dhingra 7e pg 481.