Morfometría y vascularización de la glándula tiroides en conejo (Oryctolagus cuniculus) / Morphometry and vascularization of the thyroid glands in rabbits (Oryctolagus cuniculus)

Las glándulas tiroides consisten en dos partes denominadas lobos que se encuentran en ambos lados de la laringe. El objetivo de este estudio fue caracterizar las medidas, topografía y vascularización de la glándula tiroides de conejos Nueva Zelanda. Las disecciones anatómicas se realizaron en 36 cadáveres adultos, 17 machos y 19 hembras, con masa corporal media de 2,5 kg y longitud cara-sacral media de 40 cm. Los cadáveres fueron obtenidos del sector de necropsia de la Universidad. Los especímenes tuvieron la arteria aorta torácica canalada, por la cual se inyectó solución de formaldehído al 10 %, seguida de látex coloreado. En los machos, el lobo izquierdo de la glándula tiroidea midió 1,40 x 0,40 x 0,01 cm y el derecho 1,36 x 0,56 x 0,01 cm; en las hembras, el lobo izquierdo midió 1,50 x 0,49 x 0,01 cm y el derecho 1,37 x 0,48 x 0,01cm. No hubo diferencia significativa (p> 0,05) entre las medias de las medidas entre machos y hembras, pero la extensión del lóbulo izquierdo de las hembras y la anchura del lóbulo derecho de los machos fueran significativamente mayores (p <0,05). La extremidad craneal de los lobos tiroideos se encontraba al nivel del cartílago cricoide en casi todos los especímenes. El extremo caudal presentó topografía más variable, desde el tercer hasta el décimo anillo traqueal, habiendo predominado al nivel del quinto anillo. Invariablemente, la irrigación arterial fue determinada por las arterias tiroideas izquierda y derecha, originadas de la arteria carótida común. Las anastomosis entre las arterias tiroideas fueron comunes. La constancia en las dimensiones y irrigación de la glándula tiroidea puede ser ventajosa en la elección del Coelho como modelo experimental para el estudio de esta glándula.

The thyroid glands consist of two parts called lobes located on both sides of the larynx. The aim of this study was to characterize the measures, topography and arterial irrigation of New Zealand´s rabbits thyroid glands. The anatomical dissections were performed in 36 adult cadavers, 17 males and 19 females, with a mean body mass of 2.5 kg and a mean cranium-sacral length of 40 cm. The specimens were obtained from the necropsy unit of the University. The cadavers had the thoracic aorta artery cannulated, through which 10 % formaldehyde solution was injected, followed by injection colored latex. In males, the left lobe of the thyroid gland measured 1.40x0.40x0.01cm and the right 1.36x0.56x0.01cm; in females, the left lobe measured 1.50x0.49x0.01cm and the right one was 1.37x0.48x0.01cm. There was no significant difference (p> 0.05) between the means of the measurements between males and females, but the left lobe length of the females and the right lobe width of the males were significantly higher (p <0.05). The cranial extremity of the thyroid lobes was at the level of the cricoid cartilage in almost all specimens. The caudal end showed more variable topography, from the third to the tenth tracheal ring in few specimens, but predominated at the level of the fifth ring. Invariably, arterial irrigation was determined by the left and right thyroid arteries, originating from the common carotid artery. Anastomoses between the thyroid arteries were common. The constancy in dimensions and irrigation of the thyroid gland may be advantageous in choosing the rabbit as an experimental model for the study of this gland.

Origem e principais ramificações da artéria celíaca em avestruz (Struthio camelus, Linnaeus, 1758) / Origin and main ramifications of the celiac artery of the ostrich(Struthio camelus, Linnaeus, 1758)

Foram estudados os arranjos da artéria celíaca em 30 filhotes de avestruzes (15 machos e 15 fêmeas). O comprimento médio da artéria celíaca foi 0,33±0,08cm nos machos e 0,32±0,14cm nas fêmeas, não havendo diferença nesta medida entre sexos. Não houve correlação entre o comprimento rostrossacral e o comprimento da artéria celíaca em ambos os sexos. Sua origem ocorreu ao nível do sétimo espaço intercostal na maioria dos casos, ainda que a esqueletopia tenha variado independentemente do sexo.Seu território de irrigação incluiu o esôfago, pró-ventrículo, ventrículo, baço, fígado, pâncreas, duodeno, jejuno, íleo e cecos. A artéria celíaca origina-se da aorta descendente e fornece as artérias pró-ventricular dorsal e esplênica para posteriormente se dividir em ramos esquerdo e direito. Na maioria dos avestruzes, o ramo esquerdo ofereceu ramos para o esôfago, pró-ventrículo e ventrículo em padrões variados. O ramo direito irrigou inicialmente o pâncreas, emitiu uma artéria hepática direita para o fígado,uma artéria gástrica direita para o ventrículo e terminou como artéria pancreatico duodenal para o pâncreas e porções do duodeno.Finalmente, esta artéria emitiu numerosos ramos ileocecais para o íleo e cecos direito e esquerdo. Artérias duodenojejunais e jejunais surgiram apenas em 10% e 3,33% dos animais, respectivamente. Todos apresentaram a artéria marginalis intestini tenuispercorrendo a margem mesentérica do intestino delgado. Anastomoses de ramos da artéria celíaca com os oriundos da mesentérica cranial ocorreram em 20% dos casos.

The arrangement formed by the celiac artery in 30 ostrich chicks, 15 males and 15 females were studied. The average length of the celiac artery was 0.33±0.08 cm for male and 0.32±0.14cm in females, even though there was no difference of this measurement between genders. There was also no correlation between rostrossacral length and the length of the celiac artery in both sexes. Its origin was at the level of seventh intercostal space in most cases, despite a varied skeletopy which was independent of gender. Its territory of irrigation included esophagus, proventriculus, gizzard, liver, spleen, pancreas, duodenum, jejunum, ileum and bothcecum. The celiac artery leaves the aorta and originates pro-ventricular dorsal artery and splenic artery and thus splits into two other branches: left and right. In most ostriches, left branch offered branches to the esophagus, proventriculus and gizzard in severaldifferent patterns. The right branch irrigated first the pancreas and formed a right hepatic artery to the liver, a right gastric artery to the gizzard and finished as pancreatic duodenalis artery to supply the pancreas and the ascendens and descendens portions from duodenum. Finally, this artery has formed numerous ileocecal branches to ileum and to right and left cecum. Duodenojejunal and jejunal arteries were present only in 10% and 3.33% of the ostriches, respectively. All animals showed intestini tenuis marginalisartery transiting the mesenteric border of the small intestine. Anastomoses of the intestinal celiac branches with those from cranial mesenteric artery were found in 20% of cases.