part of part of connects connects organ part lobe of thyroid gland isthmus of thyroid gland neuronames:2643 thyroid isthmus Wikipedia:Thyroid_isthmus UBERON:0001609 MA:0000727 EHDAA2:0002031 isthmus EMAPA:18195 thyroid gland isthmus A narrow median bridge that joins together the lower thirds of the two lateral (right and left) lobes of the thyroid gland and usually covers the second and the third tracheal rings; the thyroid isthmus is variable in presence and size, can change shape and size, and can encompass a cranially extending pyramid lobe (lobus pyramidalis or processus pyramidalis), remnant of the thyroglossal duct. EHDAA:5777 NCIT:C32887 FMA:49178 VHOG:0000739 SCTID:245539003 thyroid gland midbrain-hindbrain boundary