Origem e distribuição do nervo isquiático de ovinos da raça Morada Nova

The sciatic nerve is the largest nerve in the body, belonging both to the sacral plexus as the lumbosacral, and there are few studies in the literature relating to anatomy of this nerve in small ruminants. Knowing that this nerve is vulnerable to several injuries along its path and that the flesh of the pelvic limb is of high commercial value, this study aimed to understand the formation of the sciatic nerve and its innervation territories in Morada Nova sheep. The experiment was conducted at the Anatomy Laboratory of the Federal Rural University of the Semi-Arid, being rights socks used 20 carcasses heep, of the new address race, aged between 6 and 7 months of age coming from Experimental Farm EMPARN-RN. The carcasses were dissected in order to view the sciatic nerve, and the pieces kept in cold storage. After dissected and examined with the naked eye, it was observed variations in the quantity of the lumbar and sacral vertebrae of sheep, which ranged between 7 and 3 sacral lumbar vertebrae (90%) and 6 lumbar and sacral 4 (10%), changing the origin of the nerve. The sciatic nerve was formed by ventral roots L7S1S2 (75%) of L6S1S2 (10%) of L7S1S2S3 (10%) and ventral branches S1S2S3 (5%), distributing the gluteobiceps muscles, semimembranosus muscle and the semitendinosus and may also innervate the quadriceps muscle of the thigh. The knowledge of these anatomical features can effectively contribute to medical clinic, avoiding iatrogenic neurological damage order.