Isthmus of thyroid gland overlies the:
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 Berry's 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.
1st tracheal cailage
1st and 2nd tracheal cailage
2nd and 3rd and 4th tracheal cailage
3rd and 4th tracheal cailage
Thyroid