Most frequent site of branchial cyst is at:
Upper third of posterior border of sternocleidomastoid
Lower third of anterior border of sternocleidomastoid
Upper third of anteromedial border of sternocleidomastoid
Question 1 Explanation:
A branchial cleft cyst is a congenital epithelial cyst that arises on the lateral part of the neck due to failure of obliteration of the second branchial cleft (or failure of fusion of the second and third branchial arches) in embryonic development. First branchial cleft fistulae typically originate in the angle of the mandible and extend to the external auditory canal. They are often associated with the facial nerve. Rare ~5%. Second branchial cleft fistulae are most common (~95%). They are found along the anterior border of the Sternocleidomastoid muscle, pass through the carotid bifurcation and into the tonsillar pillar. Third and fourth branchial cleft fistulae are rare. The external opening occurs about 2/3 of the way down the SCM anteriorly, similar to second branchial cleft cysts. The tract ascends along the carotid sheath posteriorly to the internal carotid artery, under the glossopharyngeal nerve, and over the vagus nerve and hypoglossal nerve to open into the piriform sinus.
Mandibular nerve supplies:
Adenocarcinoma of esophagus develops in
Long standing achalasia
Question 3 Explanation:
Most esophageal cancers fall into one of two classes: squamous cell carcinomas, which are similar to head and neck cancer in their appearance and association with tobacco and alcohol consumption, and adenocarcinomas, which are often associated with a history of gastroesophageal reflux disease and Barrett's esophagus.
Endolymph is formed in
Question 4 Explanation:
Endolymph is formed in stria vascularis which forms the outer wall of scala media. It is absorbed through endolymphatic sac.
Ototoxic effects are reversible in all the following drugs if drug administration is stopped, except