Vascularização arterial, forma, topografia e morfometria da glândula tireóide em fetos de bovinos com sangue europeu

Abstract

The aim of this study was to analyze some morphometric, morphologic and topographic parameters of the arterial blood supply for the thyroid gland in 30 bovine fetuses (Bos taurus taurus), 15 male and 15 female, coming from Novilho do Valle Slaughterhouse, Jaboticabal, SP, Brazil. The thoracic aorta was canulated, latex neoprene colored solution was injected and specimens were fixed in a 10% formol solution. It was found that the mean length and width were, respectively, 15.45 mm and 15.16 mm for the right side, 18.61 mm and 16.14 mm for the left side, and 11.52 mm and 5.91 mm for the isthmus. The right side was found at level of the 2nd (80%), 3rd (10%), 4th (6.67%) or 6th (3.33%) traqueal rings. The left side was found at level of the 2nd (66.67%), 3rd (20%), 4th (3.33%) or 5th (10%) traqueal rings. The right side received the cranial and caudal thyroidea arteries in 73.34% of cases and only the cranial thyroidea artery in 26.66% of cases. The left side received the cranial and caudal thyroidea arteries in 60% of cases and only the cranial thyroidea artery in 40% of cases. The right cranial thyroidea artery gave off branches ranging from 1 to 12 twigs, with the highest frequency (3 branches) in 30% of the samples. For the left side, the range was from 2 to 9 branches, with the highest frequency (3 branches) in 36.67% of the cases. It was also found that the cranial thyroidea artery was double in 3.33% of the cases, in both the right and left sides, even so in different specimens. The caudal thyroidea artery gave off branches ranging from 2 to 5 twigs, with the highest frequency (2 branches) in 30% of the samples. For the left side, the range was from 2 to 6 branches, with the highest frequency (2 branches) in 23.34% of the cases. It was also found that the right caudal thyroidea artery was double in 6.66% of the cases while the left one was double in 3.33% of the studied specimens. Morphologically, the thyroid gland ranged from oval to the triangular shape, with the highest frequency (90% of the cases) in oval shape on both sides