system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Upper border of thyroid cailage is at
assistant
The correct answer is  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 cailage to the fouh or fifth tracheal ring The isthmus extends from second to the fouh tracheal ring Ref BDC volume3,6th edition pg 140