Keys for ANATOMY MCQs: THYROID GLAND is provided in this post.
 1: b

2: c

3: b

4: c

5: d

6: a (Superior thyroid artery is usually the first branch of external carotid artery)

7: d (Thyrocervical trunk is the branch of first part of subclavian artery)

8: c

9: c

10: c

11: a

12: a (Superior laryngeal nerve, a branch of Vagus nerve, gives rise to internal and external laryngeal nerve. External laryngeal nerve supplies the Cricothyroid muscle which is the intrinsic muscle of larynx. The muscle is responsible for stretching/tension/elongation of the vocal cord.)

13: b (Close to the apex, the nerve runs away from the artery and passes deep to the gland. So ligating the artery near the apex prevents the injury to the nerve unlike ‘away from the apex’ which may lead to nerve injury due to its close relationship with the artery.)

14: c (Recurrent laryngeal nerve is the direct branch of Vagus nerve. On the right side, the nerve arises at the root of the neck whereas on the left side it arises inside the thoracic cavity and in both cases the nerve turns upward and runs in the groove between trachea and oesophagus. The recurrent laryngeal nerve supplies the intrinsic muscles of the larynx except cricothyroid. It also provides the sensory innervation to laryngeal mucosa below the level of vocal cord.)

15: a (Reason is same as explained for question # 13. Close to the base or inferior pole the nerve and artery are closely related. So it is safe to ligate the artery away from the base of the gland in a surgical procedure requiring the removal of thyroid gland.)