Origin and Distribution of the Brachial Plexus in Two Procyonids (Procyon cancrivorus and Nasua nasua, Carnivora).

Procyon cancrivorus and Nasua nasua are two procyonids with different evolutionary adaptations to use their thoracic limbs. Therefore, this study aimed to characterize the differences in the brachial plexus between both species. Five P. cancrivorus and five N. nasua cadavers were used to perform this investigation with the permission of the bioethics committee and environmental license. Gross dissections were performed on the cervical, pectoral, and thoracic limb regions to find the origin and distribution of the brachial plexus. The brachial plexus of both species originated in a variant manner from C5-T1, C5-T2, C6-T1, or C6-T2. All brachial plexus nerves were observed and, interestingly, the musculocutaneous sent a communicating branch to the median nerve medially to the axillary artery, forming an ansa axillaris in both species. An ansa pectoralis was also observed medially to the axillary artery. Additionally, in P. cancrivorus, the musculocutaneous nerve innervates the pronator teres and flexor carpi radialis muscles and communicates with the median nerve at the elbow level to continue as a common trunk at the antebrachium. The brachial plexus has differences between both procyonids, although in both species, it could conserve a primitive arrangement present within the infraorder Arctoidea.

Comparative study of the digastric and the stylohyoid muscles between wild boars (Sus scrofa scrofa) and domestic swine (Sus scrofa domesticus): revisiting the gross anatomy.

Considering Suidae Familie as a perfect and viable experimental biomedical model for research applied to human medicine, it has been sought to describe the comparative anatomy of the digastric and the stylohyoid muscles between boars and domestic swine. Heads of Sus scrofa scrofa and Sus scrofa domesticus were dissected. The digastric muscle presented only one muscle belly as anatomical component of a tendinous origin in the jugular process of the occipital bone, and muscle insertion in the midventral edge of the caudal two thirds of the body of the mandible. Thus, its function is fundamentally associated with the lowering and the retracting of the mandible which, by the way, can deliver greater muscle power at lesser energy expense. For the stylohyoid muscle, the tendinous origin was in the laterocaudal edge of the dorsal third of the stylohyoid bone. The muscle insertion - primarily, was in the lateral and caudal edges from the mid third portion up to the ventral extremity of the thyrohyoid bone, and secondarily as a laterolateral aponeurotic blade which would unite, in a bilateral manner, an insertion that was common to the sternohyoid, the geniohyoid, and the mylohyoid muscles in a median ventral region. This morphology were similar to the two specimens studied expanding the information available, which were completely unknown for the suidae until the moment.

Anatomy of the thoracic limb muscles of wild boars (Sus scrofa, Artiodactyla: Suidae).

The study of the muscular anatomy of wild boar (Sus scrofa) is important, because it allows the understanding of the locomotor and evolutionary aspects, besides the improvement of surgical techniques used by veterinarians in swine. Thus, the objective of this study was to describe the morphology and disposition of the shoulder and arm muscles of S. scrofa. Twelve young specimens of hybrid S. scrofa, six males and six females were fixed and dissected following usual anatomy techniques. The bones of two specimens were prepared to analyze the fixation points of the muscles. The shoulder muscles presented fixation at the scapula and humerus, in distinct bone accidents, and were divided on lateral and medial faces. On the lateral face, the deltoid (divided in acromial and scapular parts), supraspinatus, infraspinatus (divided in cranial and caudal parts) and teres minor (deep to the caudal part of the infraspinatus) muscles were found. In the medial face, the subscapular, coracobrachialis and teres major muscles were observed. The arm muscles were arranged essentially around the humerus and were seen largely on its medial face, namely biceps brachii (originated by a single tendon), brachialis, tensor fasciae antebrachii (fused with the long head of the triceps brachii), triceps brachii (divided in lateral, long and medial heads) and anconeus (located mostly on the lateral side) muscles. Thus, it can be concluded that the S. scrofa presented seven muscles in the shoulder region and six muscles in the arm region, all with morphological similarities to domestic and some wild animals. Some differences were found, for the most part, in the shape, division and fixation points of certain muscles.

Morphometry of mental foramina applied to local anesthesia in hoary fox (Lycalopex vetulus Lund, 1842) / Morfometría de forámenes mentales aplicada a la anestesia local en zorro de campo común (Lycalopex vetulus Lund, 1842)

In order to perform local anaesthetic blockade of the mental nerves, it is fundamentally to determine anatomical references, including the precise identification of the mental foramina; however, the literature does not present specific data on such structures in the Hoary Fox. Therefore, the objective was describing the morphometry of the mental foramina of this specie, in order to correlate its topographies with the mandibular anatomical reference points, supporting the effective technique for mental desensitization. For this purpose, four mandibles of adult bodies of Lycalopex vetulus were used. Bilaterally, three mental foramina were observed located on the rostral third of the lateral margin of the mandibular body. One of them is more caudal, positioned ventrally to the lower third premolar tooth; a medium one, is located ventrally to the lower first premolar tooth; and a rostral one, placed ventrally to the lower intermediate incisor tooth. There were no statistically significant differences between the antimeres. Therefore, it is indicated that the local anaesthetic block of the mental nerves in this species should be performed by inserting the needle approximately 4.4 mm in a ventrodorsal direction. It is necessary positioning it perpendicularly to the ventral margin of the mandibular body and juxtaposed to its lateral face, using as anatomical reference the interalveolar space located between the first two lower premolar teeth. Thus, that the point established for anaesthetic injection (caudal limit of the ventral margin of the middle mental foramen), provides greater safety for its realization since, for small animals, the recommendation for blockade is represented by needle penetration on the direction of emergence of the mental nerve and artery from this foramen, which makes these structures more exposed to iatrogenic lesions resulting from the technique.

Para realizar el bloqueo anestésico local de los nervios mentales, es fundamental determinar referencias anatómicas, incluida la identificación precisa de los forámenes mentales; sin embargo, la literatura no presenta datos específicos referente a estas estructuras en el zorro de campo común. Por lo tanto, el objetivo fue describir la morfometría de los forámenes mentales de esta especie, para correlacionar sus topografías con los puntos de referencia anatómicos mandibulares, apoyando la técnica efectiva para la desensibilización mental. Para este propósito, se utilizaron cuatro mandíbulas de Lycalopex vetulus adultos. Bilateralmente, se observaron tres resistencias mentales ubicadas en el tercio rostral del margen lateral del cuerpo mandibular. Uno de ellos es más caudal, posicionado ventralmente hacia el tercer diente premolar inferior; uno mediano, localizado ventralmente hacia el primer diente premolar inferior; y uno rostral, colocado ventralmente al diente incisivo intermedio inferior. No se observaron diferencias estadísticamente significativas entre los antímeros. Por lo tanto, el bloqueo anestésico local de los nervios mentales en esta especie debe realizarse insertando la aguja aproximadamente 4,4 mm en dirección ventrodorsal. Es necesario colocar ésta perpendicularmente al margen ventral del cuerpo mandibular y yuxtapuesto a su cara lateral, utilizando como referencia anatómica, el espacio interalveolar ubicado entre los dos primeros dientes premolares inferiores. De este modo, el punto establecido para la inyección de anestesia (límite caudal del margen ventral del foramen mental medio), proporciona una mayor seguridad para su realización ya que, para los animales pequeños, la recomendación de bloqueo está representada por la penetración de la aguja en la dirección de emergencia del nervio mental y la arteria de este foramen, lo que hace que estas estructuras estén más expuestas a las lesiones iatrogénicas resultantes de la técnica.

Anatomical study of the ventral rami of thoracic spinal nerves in Sapajus apella (Primates: Cebidae).

This study aimed to describe the gross anatomy of the ventral rami of the thoracic spinal nerves in capuchin monkey (Sapajus apella) and compare with humans and other primate species. Eight specimens, prepared in 10% formalin solution and dissected following routine standard techniques, were used. The animals presented 13-14 pairs of thoracic spinal nerves emerging from the intervertebral foramen and divided into dorsal and ventral rami. The ventral rami of the first 12 or 13 pairs represented intercostal nerves and the latter referred to the subcostal nerve. The intercostal and subcostal nerves gave off muscular and cutaneous branches (lateral and ventral), which promote innervation of muscles and skin associated with the chest and abdominal wall. Atypical anatomy was verified for the 1st, 2nd and 7th to 13th intercostal nerves as well as for the subcostal nerve. The morphological characteristics were similar to those observed in humans and some non-human primates, especially in the absence of collateral branches.

Comparative descriptive anatomy of the femoral artery in crab-eating fox, hoary fox and maned wolf / Anatomia descritiva comparativa da artéria femoral de cachorro-do-mato, raposa-do-campo e lobo-guará

The goal of this study was to describe the anatomy of the femoral artery in wild canids such as the crab-eating fox (Cerdocyon thous), the hoary fox (Lycalopex vetulus), and the maned wolf (Chrysocyon brachyurus). Two specimens from each canid group were used. Red dyed latex was injected in the arterial system of the animals, which were then fixed in 10% formaldehyde aqueous solution and dissected following the routine techniques in macroscopic anatomy. In the three canid groups, the arterial pattern was similar to that described for domestic canids, in which the deep femoral artery rises from the external iliac artery, still in the abdominal cavity, and sends its first branch, the lateral circumflex femoral artery. A few muscular branches, one or two caudal femoral arteries, and the terminal branches ­ the descending genicular artery, the saphenous artery, and the popliteal artery ­ are all originated from the femoral artery. The origin pattern of these vessels also shows similarities with those from domestic canids, sometimes forming trunks and occasionally rising individually. Thus, it can be concluded that the anatomical pattern of the femoral artery and its branches in wild canids shows similarities with that from domestic canids, but inherent variations in each species are also present.(AU)

O objetivo deste estudo foi descrever a anatomia da artéria femoral em canídeos selvagens, como o cachorro do mato (Cerdocyon thous), a raposa do campo (Lycalopex vetulus) e o lobo-guará (Chrysocyon brachyurus). Foram utilizados dois espécimes de cada grupo canídeo. Solução de látex vermelha foi injetada no sistema arterial dos animais, que foram então fixados em solução aquosa de formaldeído a 10% e dissecados seguindo as técnicas rotineiras da anatomia macroscópica. Nos três grupos canídeos, o padrão arterial foi semelhante ao descrito para canídeos domésticos, em que a artéria femoral profunda origina da artéria ilíaca externa, ainda na cavidade abdominal, e envia seu primeiro ramo, a artéria femoral circunflexa lateral. Alguns ramos musculares, uma ou duas artérias femorais caudais e os ramos terminais - a artéria genicular descendente, a artéria safena e a artéria poplítea - são originários da artéria femoral. O padrão de origem desses vasos também mostra semelhanças com as de canídeos domésticos, às vezes formando troncos e ocasionalmente originando individualmente. Assim, pode-se concluir que o padrão anatômico da artéria femoral e seus ramos em canídeos selvagens mostra semelhanças com a dos canídeos domésticos, mas variações inerentes em cada espécie também estão presentes.(AU)