Comparative studies on the brainstem of some domestic animals : II- mesencephalon [electronic resource].
دراسات مقارنة لساق الدماغ لبعض الحيوانات المستأنسة : 2-الدماغ الأوسط.
- p.22-43.
Includes references.
The mesencephalon was the smallest part of the brainstem in all examined animals. In pig it was the smallest and takes an oblique position rostrodorsally between the rostral higher forebrain and the caudal lower hindbrain. The mesencephalon composed of dorsal tectum, ventral tegmentum, crura cerebri and traversed centerally by mesencephalic aqueduct. The longest mesencephalon to the total length of the brain and also to the brainstem was observed in sheep (12.4%, 21.7%) while the shortest one was in pig (5%, 10.8%). The rostral colliculi were larger than the caudal ones in donkey and sheep, nearly of the same size in cat but in dog and pig the caudal ones were the larger. The lemniscal trigone was rectangular in donkey, dog and cat; triangular in sheep and groove like space in pig and represented by the brachium of the caudal colliculi. The cerebral crura were thick and well prominent in donkey, relatively long in sheep, short and fan shaped in pig and in the form of thick column nearly with the same caliber along its length in dog and cat.