<prompt> Isthmus of thyroid gland overlies the:1st tracheal cailage1st and 2nd tracheal cailage2nd and 3rd and 4th tracheal cailage3rd and 4th tracheal cailage  <response>: THYROID GLAND Normal weight of thyroid gland: 20-25 gms Isthmus that is located just inferior to the cricoid cailage, usually anterior to 2nd and 3rd mainly 4th tracheal rings. A pyramidal lobe is present in about 50 of patients. Thyroid capsule is condensed into the posterior suspensory or Berrys ligament near the cricoid cailage upper tracheal rings. External laryngeal nerve runs close to the superior thyroid aery and the recurrent laryngeal nerve runs close to the inferior thyroid aery. 