Brachial Plexus in the Pampas Fox (Lycalopex gymnocercus): a Descriptive and Comparative Analysis

Abstract

Twenty thoracic limbs of ten Lycalopex gymnocercus were dissected to describe origin and distribution of the nerves forming brachial plexuses. The brachial plexus resulted from the connections between the ventral branches of the last three cervical nerves (C6, C7, and C8) and first thoracic nerve (T1). These branches connected the suprascapular, subscapular, axillary, musculocutaneous, radial, median and ulnar nerves to the intrinsic musculature and connected the brachiocephalic, thoracodorsal, lateral thoracic, long thoracic, cranial pectoral and caudal pectoral nerves to the extrinsic musculature. The C7 ventral branches contribute most to the formation of the nerves (62.7%), followed by C8 (58.8%), T1 (40.0%) and C6 (24.6%). Of the 260 nerves dissected, 69.2% resulted from a combination of two or three branches, while only 30.8% originated from a single branch. The origin and innervation area of the pampas fox brachial plexus, in comparison with other domestic and wild species, were most similar to the domestic dog and wild canids from the neotropics. The results of this study can serve as a base for comparative morphofunctional analysis involving this species and development of nerve block techniques. Anat Rec, 300:537-548, 2017. © 2016 Wiley Periodicals, Inc.

BRACHIAL PLEXUS IN THE Leopardus geoffroyi

“…Ventral branches of C7 participated in forming 70.5% of nerves of the L. geoffroyi brachial plexus. Also, it was the branch that most originated the nerves of C. thous (61.5%) (34) and L. gymnocercus (62.7%) (35) . Even though a small number of studies determined the participation percentage of each ventral branch, the findings in L. geoffroyi seems to repeat the anatomic patterns for domestic felids (38) , L. pardalis (31) , domestic dog (30) , M. foina (36) and N. nasua (37) .…”

“…Allam et al (30) determined in their study that only 20.69% of the plexuses of domestic canines were formed between the C5 and T1 branches, illustrating the participation of C5 in forming the brachiocephalicus nerve, as observed for L. geoffroyi. For wild canines (specialised cursorial) such as Atelocynus microtis (33) , Cerdocyon thous (34) and Lycalopex gymnocercus (35) and mustelids such as Martes foina (36) , the brachial plexus was restricted to four segments, being those between the C6 and T1 segments. For the procyonid Nasua nasua that uses the limbs for different functions, the plexus was also formed between the segments C5 and T1 (37) .…”

“…For L. geoffroyi, there was no formation of such trunks, occurring very distinct branches origin, similar to domestic mammals (7) . The absence of the trunk is emphasised for domestic (30) and wild canids (34,35) .…”

Functional myology of the thoracic limb in Pampas fox (Lycalopex gymnocercus): a descriptive and comparative analysis

“…), its brachial plexus formation (Souza Junior et al. ), and many aspects of its thoracic limb osteology (Souza Junior et al. ).…”

“…Detailed studies of the anatomy of the L. gymnocercus include the description of its encephalic vascularization (Depedrini & Campos, 2003, the topography of its lumbar intumescence and medullary conus , and lumbosacral (Lorenzão et al 2016), its brachial plexus formation (Souza Junior et al 2016), and many aspects of its thoracic limb osteology (Souza Junior et al 2018).…”