Morphological description of the alimentary canal and adnexal glands in Amazilia tzacatl, Amazilia saucerottei, Amazilia amabilis and Anthrachotorax nigricollis species.

The hummingbird family (Trochilidae) includes the smallest and most metabolically active vertebrates. They have a high energy demand because of their extraordinarily high metabolic rates during hovering while looking for food. The morphology of the digestive apparatus is related to the feeding habits of the species. The anatomy and histology of the digestive apparatus in these birds have not been thoroughly described except for their tongue. Therefore, this study aimed to describe the gross anatomy and histology of the alimentary canal and adnexal glands in four species from the hummingbird family: Amazilia tzacatl (n = 2), Amazilia saucerottei (n = 1), Amazilia amabilis (n = 1) and Anthracothorax nigricollis (n = 1). The alimentary canal was found to be very short. The epithelium of the oesophagus and crop showed variable degrees of keratinization and parakeratotic areas as normal conditions. A dorsal crop was observed as a differential characteristic of these birds. Like other birds, the ventricular mucosa in hummingbirds was covered and protected by the cuticle and showed a tunica muscularis constituted by three muscle layers. There was no isthmus between the proventriculus and ventriculus. The intestine presents a well-differentiated duodenum and jejunum. However, no ileum nor caeca were identified. The intestinal villi length, base width, crypt depth and area showed differences among the specimens studied among the small and large intestines. In addition, variations in thickness were observed in the smooth muscle tunica along the intestine. In all the studied species, the liver was composed of two lobes (right and left), and no gall bladder was observed during gross inspection or in histological sections. Finally, the pancreas was observed as a diffused organ forming islets related to all the small intestines. Some anatomical differences were observed among the studied species, mainly concerning Anthracothorax nigricollis. Hummingbirds showed very interesting and distinctive morphological characteristics. Hummingbirds possess unique and intriguing morphological characteristics. Future comparative studies related to the anatomy, histology and function of the digestive apparatus of hummingbirds are required. Expanding our understanding of the digestive morphophysiology in these bird species is crucial. However, it is necessary to conduct more comprehensive studies encompassing a wider range of hummingbird species and including a larger number of individuals to obtain more conclusive findings.

Lumbar vertebral pattern variation in the common opossum (Didelphis marsupialis Linnaeus, 1758): implication on lumbar nerve distribution.

The lumbar nerve distribution can differ depending on vertebral count variations among individuals of the same species. The variation in the lumbar vertebra formula and the lumbar nerve distribution in twenty adult common opossums (eight female and twelve males) was studied. Radiographs were taken to confirm vertebral identification and count. Two vertebral patterns were recognized: three specimens presented five lumbar vertebrae (5VP) and seventeen individuals presented six lumbar vertebrae (6VP). All the 6VP specimens had the same innervation pattern; however, the 5PV had three different innervation patterns (5PVa, 5VPB, and 5PVc). 5VPa and 6VP differed only in the origin of the lateral femoral cutaneous nerve (L2-L3 and L3, respectively). The differences among 5PVa, 5PVb, and 5VPc were seen in the iliohypogastric nerve, which was formed by L1 in 5VPa and 5VPb, and T13 in 5VPc. The ilioinguinal nerve was formed by L1-L2 in 5VPa and 5VPb, while it was formed by T13-L1 in 5VPc. The genitofemoral nerve was formed by L2-L3 in 5VPa, L2 in 5VPb, and L1-L2 in 5VPc. The cutaneous femoris lateralis was formed by L2-L3 in 5VPa and 5VPc, while it is formed only by L2 in 5VPb. The femoral and obturator nerves were formed by L3-L4 in 5VPa, and L2-L3 in 5VPb and 5VPc. The lumbosacral trunk originated from L4-L5-S1 in 5VP and L5-L6-S1 in 6VP. The data provided in this study may help understand the relationship between the spine and lumbosacral plexus variations and may find application in veterinary spine surgery.

Description of the arterial supply and venous drainage of the abdominal viscera in the puma (Puma concolor) (Linnaeus, 1771).

Detailed descriptions of the abdominal vasculature have not been reported on Puma concolor; thus, herein we provided a thorough description. Our findings include the following: a celiac artery branching into the hepatic and gastrolienal arteries, and this latter further branched into the left gastric, the left gastroepiploic, the lienal and three more arteries that supplied the greater omentum. We also found a cystic artery that derived from the right gastroduodenal artery; a right gastric artery that derived from the right hepatic artery; and an antimesenteric ileal artery that derived from the lateral cecal artery. The right gastric vein did not form the gastroduodenal vein as in other species, but it drained directly into the portal vein. Also, a middle pancreaticoduodenal vein was identified as the last branch of the cranial mesenteric vein. Finally, the left caudal phrenic vein drained into the left renal vein. The abdominal blood supply described herein corresponds to a single individual; further reviews are desirable to corroborate our observations and to detect potential intraspecific anatomical variations.

Anatomical description of the origin and distribution of the brachial plexus to the antebrachium in one puma (Puma concolor) (Linnaeus, 1771).

The knowledge of the anatomy of the brachial plexus in animals is of great importance due to its applicability in clinical, diagnostic and surgical procedures. The objective of the present study was to describe the anatomy of the brachial plexus in the puma. The results demonstrate a broad anatomical similarity with other felines; however, some differences were found. The formation of the brachial plexus in the puma occurred from the ventral interconnections of the last three cervical nerve segments and the first thoracic (C6, C7, C8 and T1). The N. suprascapularis emerges from C6, innervating the M. supraspinatus, the M. infraspinatus, and also the M. cleidobrachialis, the latter by a smaller branch. We found an independent branch emerging from C6 that innervates the M. serratus ventralis cervicis, not reported in other species. The innervation territory of the N. axillary includes the M. cleidobrachialis. The M. teres major was not innervated by the axillary nerve, but by an entirely independent branch that came from C6 and C7, and that also innervated the most caudal part of the M. subscapularis.

Anatomical description of the origin and distribution of the lumbosacral plexus in one puma (Puma concolor).

Wild felids often suffer spinal and limb disorders; however, their nervous system anatomy is poorly studied. Herein, the lumbosacral plexus (Plexus lumbosacralis) of an adult puma and the motor and sensitive innervation of the pelvic limb is described. We found anatomical similarities to other felids, but also some differences. Branches L4-S3 form the lumbosacral plexus (Plexus lumbosacralis) in the puma. The femoral nerve (N. femoris) arises from the union of L4-L5, while in other felids, it is formed by L5-L6. Unlike in the cat, the sartorius muscle receives branches from the saphenous (N. saphenous) and femoral nerves (N. femoris), and the lateral head of the gastrocnemius and superficial digital flexor muscles are innervated by a branch of the soleus muscle.

Body Painting of the Horse and Cow to Learn Surface Anatomy.

Gross anatomy is considered one of the most challenging subjects in teaching veterinary medicine. The use of body painting is reported in teaching surface human anatomy, but such reports are scarce in veterinary medicine. The aim of this study was to describe a practical session for teaching surface anatomy using body painting with second-semester students of veterinary medicine. Two practical sessions using live animals (equine and bovine) were offered with a focus on the locomotor and nervous systems and splanchnology. Students believed that the body painting sessions helped them to understand the localization of structures, promoting long-term retention and integration of knowledge, and to approach large animals with more self-confidence. Forty-nine students took three short theoretical and practical exams: a pre-test on splanchnology (Q1), an immediate post-test on splanchnology (Q2), and a post-test after 7 weeks on the locomotor and nervous systems (Q3). Correct answers for theoretical Q1 and Q2 were statistically different (2.04 and 3.11 out of 5, respectively; p < .001), and higher scores were found for Q3 compared with Q1 (2.49 and 1.02 out of 5, respectively). The most common error observed in practical Q1 was underestimation of the real size of organs such as lungs, rumen in cattle, and cecum in horses. The results showed that body painting sessions improved learning of anatomical concepts and could serve as a bridge between cadaver anatomy and living animal anatomy. More body painting sessions could be included in other semesters of the veterinary medicine curriculum to better integrate anatomy knowledge.

Didactic model of the chicken embryo development using modified Dawson's diaphanization and staining technique / Modelo didáctico del desarrollo embrionario del pollo usando la técnica modificada de Dawson para transparentación y tinción / Modelo didático do desenvolvimento embrionário do frango usando a técnica modificada de Dawson para diafanização e coloração

Background: didactic models are a very useful tool for pedagogy in Agrarian Science careers (i.e. Veterinary Medicine and Animal Science). Objective: the aim of this work was to create a didactic model of the chicken embryo development using modified Dawson's diaphanization and staining technique, which allows the centers of ossification to be viewed. Methods: chick embryos from day 5 to day 21 were diaphanized with KOH, stained with Alizarin Red, and stored in glycerol. Results: growth of primary ossification centers during embryonic development was easily visualized. Conclusion: to our knowledge, this is the first literature report showing an anatomical model of all embryonic stages of chicken development. Impact of this model in pedagogy must be evaluated in future works.

Antecedentes: los modelos didácticos son una muy buena herramienta para el proceso de enseñanza-aprendizaje en los cursos de Ciencias Agrarias (Medicina Veterinaria y Zootecnia, entre otros). Objetivo: hacer un modelo didáctico del desarrollo embrionario del pollo usando la técnica modificada de Dawson para transparentación y tinción, que permite visualizar los centros de osificación. Métodos: embriones de pollo del día 5 al 21 fueron transparentados con KOH, teñidos con Rojo de Alizarina y almacenados en glicerina. Resultados: se pudo visualizar el crecimiento de los centros primarios de osificación durante el desarrollo embrionario. Conclusión: este es el primer reporte en literatura que muestra un modelo anatómico de todas las etapas del desarrollo embrionario del pollo. En futuras investigaciones se debe evaluar el impacto que tiene este modelo en el proceso enseñanza-aprendizaje.

Antecedentes: os modelos didáticos são uma boa ferramenta para o processo ensino-aprendizado nos cursos de Ciências Agrárias (Medicina Veterinária, Zootecnia, entre outros). Objetivo: fazer um modelo didático do desenvolvimento do frango usando a técnica modificada de Dawson para diafanização e coloração, que permite visualizar os centros de ossificação. Métodos: Embriões de frango do dia 5 ao 21 foram transparentados com KOH, corados com Vermelho de Alizarina e armazenados em glicerina. Resultados: foi possível visualizar o crescimento dos centros primários de ossificação durante o desenvolvimento embrionário. Conclusão: este é o primeiro reporte na literatura de um modelo anatômico do desenvolvimento embrionário do frango. Futuras pesquisas devem ser focadas no impacto que tem este modelo no processo ensino-aprendizado.

Ultrastructural morphology and morphometry of the normal corneal endothelium of adult crossbred pig / Morfologia ultraestrutural e morfometria do endotélio corneal normal de suínos adultos mestiços

Corneal endothelium constitutes a monolayer of polygonal cells. The integrity and health of this layer are essential for the maintenance of normal corneal transparency. This study reported by the first time in a detailed way the ultrastructural morphology and morphometry of the corneal endothelium in normal adult crossbred pigs by using scanning electron microscopy (SEM). A regular pattern of polygonal cells, with predominantly hexagonal cells and clear cell borders, was observed. An oval nucleus that bulges in the centre of the cell, cilia (2-4) in a few peripheral cells, openings of the pinocytotic vesicles, microvilli, borders bars and interdigitated cell borders were observed. The mean endothelial cell area was significantly higher (P<0.05) in the centre than in periphery, with a lower variation coefficient in the former. The mean cell density in periphery was significantly higher (P<0.05) than in centre and 43.9 percent higher than data formerly reported by other authors using specular microscopy, showing the significant shrinkage caused by sample processing for SEM. The mean value of cell sides (pleomorfism) was 5.9, ie. predominant hexagonal shape. The percentage of hexagonal cells was significantly higher in central region (P<0.01), determining a more homogeneous structure. The parameters obtained in this study will be a basement for future investigations about the effect on pig corneal endothelium of drugs, intracamerular surgeries and storage solutions for transplants.

O endotélio corneal é uma monocamada de células poligonais. A integridade e saúde dessa camada são essenciais para a manutenção da transparência corneal normal. Este estudo reportou pela primeira vez, de forma detalhada, a morfologia ultra-estrutural e a morfometria do endotélio corneal de suínos adultos mestiços à microscopia eletrônica de varredura (MEV). A superfície endothelial corneal apresentou um padrão regular de células poligonais, com predomínio da forma hexagonal e de bordas celulares nítidas. O núcleo foi observado como protuberância arredondada no centro da célula. Também foram observados os cílios (2-4) em apenas algumas células da região periférica da córnea, as aberturas das vesículas pinocitóticas na proximidade dos cílios, as microvilosidades, as varas da borda e as bordas celulares em formato de zigzag. A área celular média foi significativamente maior (P<0,05) no centro da córnea do que na periferia, com um coeficiente de variação menor no centro da córnea. A densidade celular média foi significativamente maior na periferia (P<0,05) e 43,9 por cento maior que os dados reportados por outros autores na microscopia especular, o que demonstra o efeito da retração celular durante o processamento das amostras. O valor médio do número de lados das células (pleomorfismo) foi de 5,9, o que evidencia um predomínio do formato hexagonal. A percentagem de células hexagonais foi significativamente maior no centro (P<0,001). Os parâmetros obtidos nesta pesquisa servirão de base para estudos futuros sobre o efeito de medicamentos, cirurgias intracamerulares ou soluções para armazenamento de córneas para transplantes no endotélio corneal do suíno.

Linfosarcoma mediastínico en un perro de raza pitbull / Mediastinic lymphosarcoma in a pitbull dog

En el presente artículo se describe el caso de un linfosarcoma mediastínico en un perro de raza pitbull, diagnosticado con base en radiografías, resonancia magnética e histopatología. Se resalta enel artículo la importancia de la resonancia magnética para el diagnóstico y ubicación de neoplasias torácicas en caninos.