Nerve liable to get injured on removing the fish bone from pyriform fossa:-
**Core Concept**
The pyriform fossa is a part of the hypopharynx, and its anatomy is closely related to the recurrent laryngeal nerve (RLN). The RLN is a branch of the vagus nerve (CN X) that supplies the intrinsic muscles of the larynx.
**Why the Correct Answer is Right**
During laryngoscopy and removal of a fish bone from the pyriform fossa, the recurrent laryngeal nerve is at risk of injury due to its close proximity to this area. The RLN loops around the subclavian artery on the right side and the ligamentum arteriosum on the left side before ascending to the larynx. In the pyriform fossa, the RLN is positioned close to the thyroid cartilage and the cricoid cartilage. Damage to this nerve can lead to vocal cord paralysis, resulting in hoarseness of voice.
**Why Each Wrong Option is Incorrect**
* **Option A:** The hypoglossal nerve (CN XII) is not directly related to the pyriform fossa and is not at risk during this procedure.
* **Option B:** The superior laryngeal nerve (SLN) is a branch of the vagus nerve but is not as closely associated with the pyriform fossa as the recurrent laryngeal nerve.
* **Option D:** The glossopharyngeal nerve (CN IX) is not directly related to the pyriform fossa and is not at risk during this procedure.
**Clinical Pearl / High-Yield Fact**
The recurrent laryngeal nerve is a common site for injury during laryngoscopy and endotracheal intubation, and its damage can result in significant morbidity, including vocal cord paralysis.
**Correct Answer:** C.