has part has part has_part characteristic of has modifier abnormal thyroid gland morphology decreased thyroid gland lobe number absent thyroid gland lobe a reduction in the number of the conical shaped sections of the thyroid gland; in most mammals, the thyroid gland consists of two lobes (left and right) connected by an isthmus portion crossing the upper trachea MP:0013937 The thyroid gland varies greatly in different mammals. In dogs and cats, the gland consists of separate masses connected by an isthmus. In horse, paired lobes are highly dissociated but connected by an insubstantial isthmus. In yet other species, the thyroid has a more compact form and exhibits relatively large median (pyramidal) lobe in addition to lateral lobes. This arrangement is found in pigs and human. absent lobe of thyroid gland abnormal decreased amount lobe of thyroid gland