This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
Killian Dehiscence is in 
Select and explain. 
A. Superior constrictor, B. Inferior constrictor, C. Middle constrictor, D. None
B: Inferior constrictor
Answer: B: Inferior constrictor 
Explanation: In the posterior wall of pharynx, the lower pa of the thyropharyngeus is a single sheet of muscle, not overlapped internally by the superior and middle constrictors. This weak pa lies below the level of the vocal folds or upper border of the cricoid lamina and is limited inferiorly by the thick cricopharyngeal sphincter. This area is known as Killian's dehiscence.Pharyngeal diveicula are formed by outpouching of the dehiscence. Ref BDC volume3,sixth edition pg 234