Angiographic anatomy of the extracranial and intracranial portions of the internal carotid arteries in donkeys

Background: In horses, the extracranial and intracranial pathway of the internal carotid artery has been described. The extracranial pathway of the internal carotid artery begins at the carotid termination and runs on the dorsal surface of the medial compartment of the guttural pouch. Thereafter the internal carotid artery passes through the foramen lacerum to continue intracranially, forming part of the rostrolateral quadrants of the cerebral arterial circle (Circle of Willis). The objectives of this study were to define and record the anatomy of the carotid arterial tree and the internal carotid artery in donkeys using angiographic techniques. This is a prospective descriptive study on 26 cadaveric donkeys. Methods: Twenty six donkey cadavers of mixed, age, sex and use presented for reasons unrelated to disease of the guttural pouch were subjected to carotid and cerebral angiography using rotational angiography. Rotational angiographic and 3 dimensional multiplanar reconstructive (3D-MPR) findings were verified with an arterial latex casting technique followed by dissection and photography. Results: The following variations of the carotid arterial tree were identified: [1] the internal carotid and occipital arteries shared a common trunk, [2] the linguofacial trunk originated from the common carotid artery causing the common carotid artery to terminate as four branches, [3] the external carotid artery was reduced in length before giving rise to the linguofacial trunk, mimicking the appearance of the common carotid artery terminating in four branches, [4] the internal carotid artery originated at a more caudal position from the common carotid artery termination. Conclusion: Veterinarians should be aware that considerable variation exists in the carotid arterial tree of donkeys and that this variation may differ markedly from that described in the horse

The Macroanatomical Evaluation of N. splanchnicus Major, Minor and Imus in Donkeys (Equus asinus L.)

Eight adult donkeys of both sexes, used in applied anatomy classes, constituted the material of the study. The greater splanchnic nerve (N. splanchnicus major) was determined to ramify from the truncus sympathicus from the space between the 13th thoracic sympathetic ganglion and the 17-18th thoracic interganglionic connection on the right side and the space between the 12-13th thoracic interganglionic connection and the 16-17th thoracic interganglionic connection on the left side. The lesser splanchnic nerve (N. splanchnicus minor) was determined to be formed by fibres originating from the 14-15th thoracic interganglionic connection and the 17-18th thoracic interganglionic connection on the right side and the 13-14th thoracic interganglionic connection, the 15-16th thoracic interganglionic connection and the 17th thoracic sympathetic ganglion on the left side. The lesser splanchnic nerve (N. splanchnicus minor) was determined not to exist on the right side in one of the materials examined. The lowest splanchnic nerve (N. splanchnicus imus) was demonstrated to exist on the fight side in 4 (50%) and on the left side in 3 (37.5%) of the 8 materials examined. The thoracic splanchnic nerves were determined to give off branches to the suprarenal gland (glandula suprarenalis), behind the diaphragm and to extend to the celiac ganglion (ganglion celiaca). No marked difference was observed between the right and left sides

The Morphology of the Cervico-thoracic Sympathetic System in Donkeys (Equus asinus L.)

Five adult donkeys of both sexes, used in applied anatomy classes, and perfused with formalin for teaching purposes, constituted the study material. Ganglion cervicale caudale of the examined materials has observed to exhibit individually variable situation as to extend on the left side of the median line, at the alignment of the first and second intercostal spaces and on the right side between the level of the first and third costa. The ganglion extended more caudally on the right side of median line. The lateral surface of the ganglion was determined to be covered with the m. scalenus medius. On the both sides of the median plane, the ganglion cervicale caudale was seen to be situated on the lateral surface of the m. longus colli. On the left side, the ganglion overlapped the oesophagus in two cadavers and on the right side it was situated within a groove between the m. longus colli and trachea in three cadavers. The rami communicantes received by the ganglion cervicale caudale originated from the eighth cervical and first thoracic spinal segments. The ganglion cervicale caudale was formed by the coalescence of the last cervical and first three thoracic sympathetic ganglia. The ganglion cervicale caudale gave off branches that formed the rami communicantes, plexus cardiacus, n. vertebralis and ansa subclavia. One branch extended from the ganglion to the plexus brachialis. in one specimen, two sympathetic-parasympathetic communicating branches were observed to extend from the ansa subclavia and near by the origin of the truncus sympathicus to the n. vagus. In one of the donkeys examined, a branch originating from the ganglion cervicale caudale on the left side of the median plane was determined to end on the ligamentum arteriosum. A microscopic ganglion structure suggesting the existence of the ganglion cervicale medium was determined in a donkey