Bone Anatomy of the Thoracic Limb in the Common Hippopotamus (Hippopotamus amphibius) and White Rhinoceros (Ceratotherium simum)

SUMMARY: Although megaherbivores do not belong to the Brazilian fauna, they can be found in national zoos, which makes it important to know the anatomy of the locomotor apparatus to contribute to the clinical routine of zoos and veterinary rehabilitation centers. Thus, the aim of this study was to describe the anatomical structures of the thoracic limb bones in the common hippopotamus (Hippopotamus amphibius) and white rhinoceros (Ceratotherium simum) and to compare them with the bone structures described for other ungulates. The scapula had a triangular appearance in the common hippopotamus, whereas in the white rhinoceros it had a rectangular appearance. The acromion was observed only in the common hippopotamus scapula. The hippopotamus humerus did not have the intermediate tubercle, only the greater and lesser tubercles, unlike the rhinoceros which also has the intermediate tubercle. The two megamammals studied had an ulna not incorporated to the radius and seven carpal bones distributed in two bone rows. The common hippopotamus had four digits and four metacarpal bones, while the white rhino had three digits, hence three metacarpal bones. Although with some species-specific differences, the bone anatomy found in the studied megaherbivores was similar to that described for domestic ungulates, such as horses and cattle. The fact that the bones studied belong to articulated skeletons of the collection of the Museum of Anatomy made it difficult to identify some anatomical structures. This study can help veterinarians in bone health care, animal welfare and comfort of such species present in Brazilian zoological parks.

Aunque los megaherbívoros no pertenecen a la fauna brasileña, se pueden encontrar en zoológicos nacionales, lo que hace importante conocer la anatomía del aparato locomotor para contribuir a la rutina clínica de los zoológicos y de los centros de rehabilitación veterinaria. Por tanto, el objetivo de este estudio fue describir las estructuras anatómicas de los huesos de los miembros torácicos en el hipopótamo común (Hippopotamus amphibius) y el rinoceronte blanco (Ceratotherium simum) y compararlas con las estructuras óseas descritas para otros ungulados. La escápula tenía una apariencia triangular en el hipopótamo común, mientras que en el rinoceronte blanco tenía una apariencia rectangular. El acromion se observó sólo en la escápula del hipopótamo común. El húmero del hipopótamo no tenía el tubérculo intermedio, sólo los tubérculos mayor y menor, a diferencia del rinoceronte que también tiene el tubérculo intermedio. Los dos ejemplares de megamamíferos estudiados tenían una ulna no incorporada al radio y siete huesos del carpo distribuidos en dos filas óseas. En el hipopótamo común se observaron cuatro dedos y cuatro huesos metacarpianos, mientras que en el rinoceronte blanco se encontraron tres dedos, por lo tanto, tres huesos metacarpianos.A pesar de algunas diferencias específicas de cada especie, la anatomía ósea encontrada en los megaherbívoros estudiados fue similar a la descrita para los ungulados domésticos, tal como los caballos y el ganado. El hecho de que los huesos estudiados pertenezcan a esqueletos articulados de la colección del Museo de Anatomía dificultó la identificación de algunas estructuras anatómicas. Este estudio puede ayudar a los veterinarios en el cuidado de la salud ósea, el bienestar animal y el confort de las especies presentes en los parques zoológicos brasileños.

Morphological description of extrinsic muscles of the thoracic limb in a specimen of pudu (Pudu puda) / Descripción morfológica de la musculatura extrínseca del miembro torácico de un espécimen de pudú (Pudu puda)

SUMMARY: The pudu (Pudu puda) is classified as an artiodactyl of the Cervidae family. It is a native species found in Argentina and Chile. It is estimated that its population has been substantially reduced due to several causes, such as loss of forests, predation, hunting, and vehicle accident. Therefore, this species is protected due to its vulnerable conservation status. The extrinsic muscles of the thoracic limb have great importance in the biomechanical functionality of the suspension of the limb, neck, and head, as well as participating in the movement of the thoracic wall and thoracic limb. The objective of the present study is to describe the extrinsic musculature of the thoracic limb of a specimen of pudu, comparing the results with those described for domestic ruminants in the classical anatomical bibliography. Basic procedures: All extrinsic muscles were analyzed, describing shape, distribution, origin, and insertion. The results indicate that the pudu specimen has anatomical characteristics similar to domestic ruminants; however, some differences should be considered. Main findings: The brachiocephalicus muscle has an evident clavicular intersection that separates it into cleidobrachialis, cervicalis, and mastoideus pars. The pectoralis superficialis muscle has two distinct and independent pars, and the pectoralis profundus muscle has a partial fusion with the latissimus dorsi and cutaneous trunci muscles. The subclavius muscle is small and has an elongated shape and goes deep into the cephalic vein, just at the point it is a tributary of the external jugular vein. The results of this study present specific anatomical features of Pudu puda providing novel reference information and expanding scientific knowledge of this scarcely studied wild species.

RESUMEN: El pudu (Pudu puda) se clasifica como un artiodáctilo de la familia Cervidae. Es una especie nativa que se encuentra en Argentina y Chile y se estima que su población se ha reducido sustancialmente debido a varias causas, tal como la pérdida de bosques, depredación, caza y accidentes de vehículo. Debido a lo anterior esta especie está protegida por su estado de conservación vulnerable. Los músculos extrínsecos del miembro torácico tienen gran importancia en la funcionalidad biomecánica de la suspensión del miembro, el cuello y la cabeza, además de participar en el movimiento de la pared torácica y el miembro torácico. El objetivo del presente estudio es describir la musculatura extrínseca del miembro torácico de un ejemplar de pudu, comparando los resultados con los descritos para rumiantes domésticos en la bibliografía anatómica clásica. Se analizaron todos los músculos extrínsecos, describiendo la forma, distribución, origen e inserción. Los resultados indican que el espécimen de pudu tiene características anatómicas similares a las de los rumiantes domésticos; sin embargo, deben tenerse en cuenta algunas diferencias. Hallazgos principales: El músculo braquiocefálico tiene una interección clavicular evidente que lo separa en pars cleidobraquial, cervical y mastoideo. El músculo pectoral superficial tiene dos porciones distintas e independientes, y el músculo pectoral profundo tiene una fusión parcial con los músculos latissimus dorsi y cutáneo del tronco. El músculo subclavio es pequeño y tiene una forma alargada y se ubica profundamente a la vena cefálica, justo en el punto en el que es un afluente de la vena yugular externa. Los resultados de este estudio presentan características anatómicas específicas de Pudu puda proporcionando información de referencia novedosa y ampliando el conocimiento científico de esta especie silvestre escasamente estudiada.

Descripción morfológica y morfométrica de la miología intrínseca del miembro torácico en un ejemplar de pudú (Pudu puda) / Morphological and morphometric description of thoracic limb intrinsic myology in a specimen of pudu (Pudu puda)

El pudú (Pudu puda) se clasifica como un artiodáctilo de la familia Cervidae y es el ciervo más pequeño. Se estima que su población se ha reducido, esto debido a varias causas, como son la pérdida de los bosques, depredación, caza y atropellos. El objetivo del presente estudio es describir la musculatura intrínseca del miembro torácico de un ejemplar de pudú, comparando los resultados observados con lo descrito para rumiantes domésticos en la bibliografía anatómica clásica. Se estudió la musculatura desde proximal hacia distal, dividiendo al miembro en cuatro regiones topográficas: región escapular, braquial, antebraquial y de la mano. Además, se realizó un estudio morfométrico indicando el largo, ancho y grosor de los músculos. Los resultados indican que el ejemplar de pudú posee características anatómicas similares a rumiantes domésticos, sin embargo, se deben considerar algunas diferencias, tales como: la porción escapular del m. deltoides se une de manera aponeurótica con el m. infraespinoso; las dos cabezas del m. flexor ulnar del carpo se encuentran altamente fusionadas; no se observó el tercer tendón del m. bíceps braquial; el m. tríceps braquial es bien desarrollado y presenta cuatro cabezas musculares bien diferenciadas; el m. ancóneo permanece de manera independiente de la cabeza lateral del m. tríceps; el m. flexor digital profundo presenta cuatro cabezas y el m. interóseo es macroscópicamente tendinoso. La información entregada en este estudio corresponde a un aporte anatómico que permite ampliar el conocimiento científico de esta especie que se encuentra poco estudiada, protegida y vulnerable.

The pudú (Pudu puda) is classified as an artiodactyl and is the smallest deer of the Cervidae family. It is estimated that its population has been reduced for a number of reasons, such as loss of forests, predation and hunting. The objective of this study is to describe the intrinsic musculature of the thoracic limb of a Pudu specimen, comparing the results with those described for domestic ruminants in anatomical literature. Musculature was studied from proximal to distal, dividing the limb into four topographic regions: scapular, brachial, antebrachial and hand regions. In addition, a morphometric study was conducted indicating the length, width and thickness of the muscles. The results indicate that the Pudu species has anatomical characteristics similar to those of domestic ruminants. However, some differences should be considered, such as the scapular portion of M. deltoides joins aponeurotically with M. infraspinatus; the two heads of M. carpis ulnaris are highly fused; the third tendon of M. biceps brachii; the M. triceps brachii is well developed and has four distinct muscle heads; the M. Anconeus remains independent of the lateral head of M. triceps brachii; the M. digitorum profundus features four heads and the M. interosseous is macroscopically tendinous. The information provided in this study corresponds to an anatomical contribution that allows furthering scientific knowledge of this protected and vulnerable species, which is scarcely studied.

Gross anatomy of the intrinsic muscles of the scapular and humeral joint regions in crab-eating fox (Cerdocyon thous, Linnaeus 1776) / Anatomia macroscópica dos músculos intrínsecos das regiões escapular e da articulação do úmero de cachorro-do-mato (Cerdocyon thous, Linnaeus 1776)

The crab-eating fox (Cerdocyon thous) is a wild canid with a wide distribution in South America that is susceptible to traumas due to road kills - an event in which some specimens can survive. Therefore, anatomical studies in their thoracic limbs may be a base for rehabilitation. Six dead specimens were donated by Wildlife Rescue Centre of CORPOCALDAS (Environmental Authority of the Department of Caldas in Colombia), which were then filled with silicone rubber via the common carotid artery, and later fixed with formaldehyde through the external jugular vein. One male was dissected in fresh, and after a week, the others were dissected on the scapular and humeral joint regions. The intrinsic muscles of these regions in the crab-eating fox were homologous to domestic dog, with similar characteristics in terms of shape, origin, insertion, innervation and arterial blood supply. However, the crab-eating fox did have some differences, such as its supraspinatus muscle being conformed by two bellies and attached into the articular capsule of the humeral joint in same manner as the subscapularis muscle, thus conferring greater stability to the humeral. However, the clinical and surgical approaches that must be performed in this region may be homologous to the domestic dog.

Cachorro-do-mato (Cerdocyon thous) é um canideo selvagem amplamente distribuído na América do Sul, susceptível a traumatismos por atropelamentos em rodovias, eventos nos quais alguns animais podem sobreviver. Portanto, estudos anatômicos em seus membros torácicos podem servir como base para sua reabilitação. Seis espécimes mortos foram doados pelo Centro de Resgate de Vida Selvagem da Corporación Autónoma Regional para el Desarrollo de Caldas - CORPOCALDAS, os quais foram preenchidos com borracha de silicone pela artéria carótida comum, e depois fixados com formaldeído através da veia jugular externa. Um macho foi dissecado a fresco e após uma semana, os outros foram dissecados nas regiões da articulação escapular e umeral. Os músculos intrínsecos dessa região no cachorro-do-mato eram homólogos às dos cães domésticos, com características semelhantes na forma, origem, inserção, inervação e suprimento de sangue arterial. No entanto, o cachorro-do-mato apresenta algumas diferenças, como músculo supraespinhal conformado por duas cabeças e unidos na cápsula articular da articulação umeral, da mesma forma que o músculo subescapular, características essas que devem conferir maior estabilidade à articulação do úmero. Apesar disso, as abordagens clínicas e cirúrgicas realizadas nesta região podem ser homólogas ao cão doméstico.

Descripción anatómica de la musculatura intrínseca del miembro torácico de león (Panthera leo) / Anatomical description of the intrinsic muscle of thoracic limb of lion (Panthera leo)

El presente estudio tuvo como objetivo el describir la musculatura intrínseca del miembro torácico del león africano (Panthera leo). Para tal efecto se utilizó un ejemplar hembra, donado por el Zoológico Metropolitano de Santiago-Chile, fijado y conservado. La disección se llevó a cabo, de proximal a distal, considerando las cuatro regiones topográficas de dicho miembro: Cintura Escapular, Brazo, Antebrazo y Mano. Se discuten y comparan los hallazgos anatómicos observados, con lo descrito para el gato doméstico y trabajos realizados por otros autores en Ocelote (Leopardus pardalis), Puma (Puma concolor) y en la propia especie en estudio. La finalidad del presente trabajo fue aportar al conocimiento de la anatomía de especies exóticas, con proyección médico quirúrgica.

The objective of this study was to describe the intrinsic muscles of the thoracic limb of the African lion (Panthera leo). For this purpose a fixed and preserved female specimen donated by the Metropolitan Zoo in Santiago, Chile, was used. The dissection was carried out, from proximal to distal, considering the four topographical regions of that limb: Scapular girdle, arm, forearm and hand. Anatomical findings observed are discusses and compared to those described for the domestic cat and works by other authors in ocelot (Leopardus pardalis), puma (Puma concolor) and the species under study. The purpose of this work was to contribute to the knowledge of the anatomy of this exotic species, with medical and surgical projections.

Origem e distribuição das principais artérias do membro torácico de Cuniculus paca (Linnaeus, 1766) / Origin and distribution of the main arteries of the thoracic limb of Cuniculus paca (Linnaeus, 1766)

Objetivou-se descrever as artérias do membro torácico da paca (Cuniculos paca Linanaeus, 1766), mediante a dissecação da região. Para tanto, foram utilizadas 10 pacas adultas, machos ou fêmeas, pesando entre cinco e 10 kg do plantel de pacas do setor de Animais Silvestres da FCAV, Unesp, Jaboticabal-SP. Nos animais, injetou-se látex pela artéria carótida comum esquerda para preencher e corar todo o sistema arterial, seguido pela fixação em formaldeído a 10% e conservação em solução salina a 30% para dissecação anatômica das principais artérias do arco aórtico, braço e antebraço, identificando-se a origem e distribuição destes vasos. Os resultados foram foto documentados e discutidos com base na literatura sobre os animais domésticos, e roedores selvagens. De forma geral, as artérias do membro torácico da paca, assemelham-se com as dos carnívoros domésticos, do rato e da cobaia.(AU)

The aim of this study is to describe the arteries of the thoracic limb of paca (Cuniculos paca Linanaeus, 1766) by dissecting the region. We used 10 adult paca, males and females, weighting between five to 10 kg obtained from the breeding group at the Wild Animals Sector of FCAV, Unesp, Jaboticabal-SP. The animals were injected with latex by the left common carotid artery to fill and stain all the arterial system, followed by the fixation in 10% formaldehyde and preservation in 30% saline solution for anatomical dissection of the main arteries of the aortic arch, arm, forearm, identifying the origin and distribution of these vessels. The results were photodocumented and discussed based on literature about domestic animals and wild rodent. In general, the arteries of the thoracic limb of paca are similar to the domestic carnivores, rat and guinea pig.(AU)

Origin and distribution of the brachial plexus in wild boar (Sus scrofa Linnaeus, 1758) / Origem e distribuição do plexo braquial de javali (Sus scrofa Linnaeus, 1758)

The origin and distribution of the brachial plexus in wild boar (Sus scrofa), a mammal belonging to the Suidae family were studied. Twelve specimens of wild boar, which were fixed in 10% formalin solution through different points of subcutaneous, intravenous, intramuscular, and intracavitary injections, following by immersing the specimens in the same solution were used. In present study, the brachial plexus of wild boar was a set of nerve fibers formed by the ventral branches from the fifth (C5) to eighth (C8) cervical and the first (T1) thoracic spinal nerves. The subclavian nerve was originated from C5, while the suprascapular nerve had its origin from C5 to C7. The cranial and caudal subscapular nerves were predominantly originated from C6 and C7, as well was the axillary nerve. The origin of the cranial and caudal pectoral nerves was from C7-C8 and C8-T1, respectively. The musculocutaneous nerve was mostly originated from C6 and C7, while the median and radial nerves had origin from C7 to T1. The origin of the ulnar, thoracodorsal, and lateral thoracic nerves was mostly from C8 and T1, while the long thoracic nerve was predominantly originated from C7 and C8. All nerves were responsible for the innervation of scapular girdle structures, arm, forearm, thorax and abdomen. In conclusion, the origin and distribution of the brachial plexus nerves in wild boar (Sus scrofa) are similar to domestic swine rather than to other wild species described in the literature.

O javali (Sus scrofa) é um mamífero que pertencem família Suidae. Estudou-se a origem e distribuição do plexo braquial de javali. Utilizou-se 12 exemplares destes animais, que foram fixados em solução aquosa de formaldeído a 10% mediante diferentes pontos de injeção subcutânea, intravenosas, intramuscular e intracavitária, seguindo-se a imersão dos espécimes em recipientes contendo a mesma solução. O plexo braquial de javali é um conjunto de nervos formados por fibras dos ramos ventrais do quinto ao oitavo nervos espinhais cervicais e do primeiro nervo espinhal torácico. O nervo subclávio originou-se de C5, subescapulares cranial e caudal de C6 a C7, supraescapular de C5 a C7, peitorais cranial e caudal de C7 a C8, axilar de C7 a C8, musculocutâneo de C6 a C7, mediano de C7 a T1, radial de C7 a T1, ulnar de C8 a T1, toracodorsal de C8 a T1, torácico lateral de C8 a T1, torácico longo de C7 a C8 e subclávio de C5, os quais foram responsáveis pela inervação de estruturas do cíngulo escapular, braço, antebraço, tórax e abdome. Em conclusão, a origem e distribuição dos nervos do plexo braquial de javali (Sus scrofa) são mais similares aos suínos domésticos do que com outras espécimes silvestres descritas na literatura.

Formação do plexo braquial e sistematização dos territórios nervosos em membros torácicos de lobos marinhos / Arctocephalus australis Brachial plexus formation and the nervous territories on thoracic limb of Arctocephalus australis

Para a realização do estudo acerca do plexo braquial (PB) e dos territórios nervosos do membro torácico de lobosmarinhos (Arctocephalus australis) foram utilizados dois animais. A pele foi retirada e procedeu-se a identificação da musculatura do membro torácico e região peitoral. Em seguida foram aplicadas compressas de solução de ácido acético glacial 3% na musculatura, com o intuito de facilitar a dissecação realizada macroscopicamente. Nos espécimes analisados notou-se a emergência do plexo braquial a partir do sexto nervo cervical até o primeiro nervo torácico. Destas quatro raízes se formam os troncos de nervos de mesmo número, cujos ramos ventrais constituirão seu arranjo e distribuição territorial. Destes quatro troncos surgem os 12 nervos componentes do PB, sendo encontrados nervos que se formam a partir de apenas um segmento (supra-escapular, peitoral cranial, torácico lateral, toracodorsal e torácico longo) e também nervos que surgem a partir de mais de um segmento, sendo assim denominados plurissegmentares (subescapular, músculo-cutâneo, axilar, mediano, peitoral caudal, ulnar e radial). Nesse sentido, foi observada uma constância na inervação da musculatura, articulações e ossos do membro torácico, de onde podemos assim inferir que existe um padrão claramente definido na delimitação dos territórios nervosos.

For the study concerning the brachial plexus (BP) and the nervous territories of the thoracic limb of South American Fur Seal (Arctocephalus australis), two animals had been used. Their skin was removed and the musculature of the thoracic limb and pectoral region was identified. After that compresses of glacial acetic acid solution of 3% had been applied in the musculature, in order to facilitate the carried through dissection. In analyzed specimens it was observed the emergency of BP from the sixth cervical nerve until the first thoracic nerve. From these four roots trunks of nerves of the same number are formed, whose ventral branches will constitute its arrangement and territorial distribution. From these four trunks emerge the 12 component nerves of the BP, some of them come from only one segment (supra scapular, cranial pectoral, lateral thoracic, thoraco-dorsal and long thoracic), while others come from more than a segment (sub scapular, muscle-cutaneous, axillary, median, caudal pectoral, ulnar and radial). In this direction,this observed constancy in the innervation of the musculature, joints and bones of the thoracic limb, led us to infer that a definite pattern in the delimitation of the nervous territories clearly exists.

The suspensory apparatus and digital flexor muscles of the llama (Lama glama) 1: The thoracic limb / El aparato suspensorio y los músculos flexores digitales de la llama (Lama glama) 1: El miembro torácico

The digital flexor muscles of the thoracic limb of four llamas were dissected and illustrated to provide data about the suspensory (support) apparatus and weight bearing structures. An extensive literature search was performed and yielded incomplete information about these anatomical structures. The popularity of the llama world wide as a domesticated animal used for show and fiber has increased in the recent years. It is helpful to describe the anatomy fully to aid in understanding of the species and treatment of pathologic conditions. The description of the anatomical structures and the original illustrations demonstrate genuine peculiarities and differences between the llama and domestic ruminants. In llamas, the three heads of the deep digital flexor muscle (DDF) originate and connect with each other in a very peculiar combination, with one tendon receiving an attachment from the flexor carpi ulnaris muscle (FCU). The superficial digital flexor muscle (SDF) has a thin tendon which is fused with the palmar fascia and then broadens. There are no interflexor muscles. Additionally, unexpected lumbricalis muscles are found in the distal limb and vary in number between the fore and hind limb. The anatomy of the suspensory apparatus in the thoracic limb is evaluated in this paper.

Fueron disecados e ilustrados los músculos flexores digitales del miembro torácico de cuatro llamas con la finalidad de aportar datos sobre el aparato suspensor (de apoyo) que soportan estas estructuras. Se realizó una extensa búsqueda bibliográfica dada la incompleta información existente de estas estructuras anatómicas. La popularidad de la llama en todo el mundo como uno de los animales domésticos utilizados ha aumentado en los últimos años. Es importante describir detalladamente la anatomía de esta especie para su tratamiento en condiciones patológicas. La descripción de las estructuras anatómicas y las ilustraciones originales demuestran peculariedades genuinas y diferencias entre la llama y los rumiantes domésticos. En llamas, las tres cabezas del músculo flexor profundo de los dedos se originan y se conectan entre ellas en una muy peculiar combinación, con uno de los tendones recibiendo un fascículo del músculo flexor ulnar del carpo. El músculo flexor superficial de los dedos tiene un tendón delgado el cual se fusiona con la fascia palmar y luego se amplía. No existen músculos interflexores. Adicionalmente, fueron encontrados músculos lumbricales en la extremidad distal y variaban en número entre los miembros. Finalmente, en este trabajo se evalúa el aparato suspensorio del miembro torácico.