Creation Nerves of the Lumbar and Sacral Plexus in California Sea Lions (Zalophus Californianus) and Northern Elephant Seals (Mirounga Angustirostris)/Formiranje Nerava Iz Lumbalnog I Sakralnog Pleksusa Kod Kalifornijskog Morskog Lava (Zalophus Californianus) I Severnomorskog Slona (Mirounga Angustirostris)

Abstract

The lumbosacral plexus was investigated in the California sea lion and Northern elephant seal. In 9 California sea lions and 2 Northern elephant seals the femoral nerve rises from the ventral branches of the 3 rd and 4 th lumbar nerves, whilst in one male and two specimens of the Northern elephant seal the 5 th lumbar nerve was also involved. Ventral branches of the 3 rd and 4 th lumbar nerves comprised the obturatorius nerve in 7 specimens; in 3 specimens the 5 th lumbar nerve additionally supplements the obturatorius nerve. In Northern elephant seals the obturatorius nerve originates from the ventral branches of the 3 rd , 4 th and 5 th lumbar nerves. The ischiadic nerve originates from the ventral branches of the 4 th , 5 th lumbar and 1 st sacral nerves in 8 specimens California sea lions and in 2 North elephant seals. In 2 specimens of both species the 2 nd sacral nerve also participates. The gluteal nerve created ventral branches of the 5 th lumbar and 1 st sacral nerves in three specimens; however in one specimen the 4 th and 5 th lumbar nerves gave rise to the same nerve in the Northern elephant seal. In California sea lions the gluteal nerve originates from the ventral branches of the 5 th lumbar nerve in seven specimens, nonetheless in 3 specimens the 4 th lumbar nerve also participates in its formation.