Right lobe of thyroid gland

The right lobe of the thyroid gland is one of the two lateral lobes that compose the thyroid gland, a butterfly-shaped endocrine organ located in the lower anterior neck between the levels of C5 and T1. The right lobe lies on the right side of the trachea, connected to the left lobe by a midline bridge of tissue called the isthmus. Each lobe is roughly half the size of a plum, with an average length of 50-60 mm, and the entire gland typically weighs approximately 25-30 grams.

Anatomical relations: The right lobe is enveloped by the visceral fascia and is covered anteriorly and laterally by the strap muscles (sternothyroid, sternohyoid, and superior belly of the omohyoid). Posterolaterally, the common carotid artery, internal jugular vein, and vagus nerve run within the carotid sheath. The lobe is attached to the cricoid cartilage and the first two tracheal rings by the ligament of Berry (posterior suspensory ligament), and the recurrent laryngeal nerve courses in close proximity to this ligament a relationship of critical surgical importance.

Blood supply to the right lobe is provided by the superior thyroid artery (a branch of the external carotid artery) and the inferior thyroid artery (from the thyrocervical trunk).

Functional and morphological asymmetry: Studies using ultrasonography have consistently demonstrated that the right lobe is typically larger than the left lobe. The asymmetry in lobe volume has also been associated with handedness and the position of the esophagus, with subjects whose esophagus deviates to the left tending to have a larger right lobe.