Brachial plexus in the Leopardus geoffroyi

Abstract

Six thoracic limbs from four Leopardus geoffroyi specimens were dissected in order to describe origin and distribution of nerves forming the brachial plexuses. The brachial plexus is a result of connections between ventral branches of the last four cervical nerves (C5, C6, C7 and C8) and the first thoracic nerve (T1). These branches are the origin of the suprascapularis, subscapularis, axillary, musculocutaneous, radial, median and ulnar nerves to the intrinsic musculature, and form the brachiocephalicus, thoracodorsal, lateral thoracic, long thoracic, cranial pectoral and caudal pectoral nerves to the extrinsic musculature. The C7 ventral branch is mainly responsible for formation of nerves (70.5%), followed by C8 (47.4%), C6 (29.5%), T1 (19.2%) and C5 (7.7%). From 78 dissected nerves, 65.4% of nerves resulted from a combination of two or three branches, while only 34.6% of nerves originated from a single branch. Through comparison with other carnivoran species, the origin and innervation area of the Geoffroyi's Cat brachial plexus were most similar to those of the domestic cat, particularly among those nerves extended to the intrinsic musculature. The results of this study suggest that nerve block techniques currently used in dogs and cats might be efficient in Geoffroyi's Cat too.Keywords: Animal anatomy; Pampa's biome; Wild carnivores; Wild felines