Anatomical studies on the prediaphragmatic portion of systema nervosum pars sympathica of the buffalo (Bubalus bubalis).

The gross disposition of the prediaphragmatic portion of systema nervosum pars sympathica was studied in six male buffalo calves after careful dissection. The cranial cervical ganglion, the cervicothoracic ganglion and the ansa subclavia were present bilaterally. Rarely a middle cervical ganglion was also encountered. The vertebral ganglia were present in most of the animals. The cranial cervical sympathetic trunk joined the N. Vagus at the level of atlas and the caudal cervical sympathetic trunk separated from the N. vagus at the sixth cervical vertebral level. The ansa subclavia joined the vertebral and the cervicothoracic ganglia. The myelinated fibres in the sympathetic trunk showed a fascicular arrangement. They were mostly of 2 to 4 mum in external diameter. The number (mean value) of myelinated fibres in the cranial cervical trunk was 8,981 +/- 2,016 and their density was 3,379/mm2. In the caudal cervical trunk, there was 10,345 +/- 3,424 myelinated fibres with a density of 3,679/mm2. In the ansa subclavia, the corresponding values were 3,301 +/- 421 and 2,456/mm2 respectively. The interganglionic trunk between the vertebral and the cervicothoracic ganglia revealed 9,843 +/- 4,602 myelinated fibres and their density was 3,698/mm2. In the interganglionic trunks between the third and the fourth and the fourth and fifth thoracic ganglia, the total number of myelinated nerve fibres was 10,540 +/- 4,127 and 9,217 +/- 1,367 respectively and their density values were 2,750/mm2 and 2,808/mm2 respectively. The corresponding values for the N. transversarius were 26,140 +/- 3,807 and 2,433/mm2 respectively. Ganglion cells were found along the caudal cervical sympathetic trunk and the thoracic sympathetic trunk. A fascicle of umnyelinated fibres was also found in the cervical sympathetic trunks.