Isthmus of thyroid gland lies against following tracheal rings
High-Yield Explanation
The thyroid gland lies against veebrae C5, C6, C7 and T1 embracing the upper pa of the trachea Each lobe extends from the middle of thyroid cailage to the fouh to fifth tracheal ring The isthmus extends from the second to fouh tracheal ring. Ref BDC volume 3,Sixth edition pg 141