Origin and distribution of the sciatic nerve in catingueiro-deer (Mazama gouazoubira)

摘要

Martins T.M.M., Pereira K.F., Lima F.C., Santos A.L.Q. & Malysz T. 2013. [Origin and distribution of the sciatic nerve in catingueiro-deer (Mazama gouazoubira).] Origem e distribuicao do nervo isquiatico no veado-catingueiro (Mazama gouazoubira). Pesquisa Veterinaria Brasileira 33(2): 273-278. Laboratorio de Anatomia Humana e Comparativa, Curso de Ciencias Biologicas, Universidade Federal de Goias, Campus Jatai, BR364 Km192, Setor Parque Industrial, Jatai, GO 75800-000, Brazil. E-mail: taismalysz@yahoo.com.br This study aimed to describe the origin and distribution of the sciatic nerve in catingueiro-deer (Mazama gouazoubira). Two animals of the species, obtained post mortem by trampling on the highway, were used for the study meeting the requirements of the Governing Law (1.153/95). By dissection the skin was completely removed and the animals were fixed in aqueous 10% formaldehyde solution. Through dorsolateral access, superficial gluteal muscle, biceps femoris muscle and gluteus medius muscle were cut at their insertion and folded, to view the origin and distribution of the sciatic nerve on both sides of the animals. Images were recorded with a digital camera (Sony a200 Camera, 10.2mpx) and results were described based on Veterinary Anatomical Nomina. The source data of the sciatic nerve in both specimens showed that the nerve originates from the ventral branches of S1 and L6, and could have contribution from S2. After its emergence through the greater sciatic foramen on both the sides, the sciatic nerve supplies branches to gluteus medius muscle, gluteus deep muscle, superficial gluteal muscle, gluteobiceps muscle, biceps femoris muscle, semimembranosus muscle, semitendinosus muscle and gastrocnemius muscle. Near the mid-thigh the sciatic nerve divides into the tibial nerve and common peroneal nerve which innervate the muscles of the distal hind limb. Moreover, the cutaneous nerve flow can cause the common peroneal nerve or tibial nerve. In conclusion, in Mazama gouazoubira specimens studied, the sciatic nerve originated from the ventral branch of spinal L6 and S1, which may or may not have the contribution from S2. In its distribution stem originate the gluteal nerve, the caudal femoral cutaneous nerve and muscular branches, which together innervate the muscles gluteus medius, gluteus deep, superficial gluteal, gluteobiceps, biceps femoris, semitendinosus, semimembranosus, adductor and gastrocnemius. Distally the sciatic nerve bifurcates into the common peroneal and tibial nerve, which innervates the distal hind limb.