Anatomical and Histological study for the Brain of the locally breed chicken( gallus domesticus)

The anatomical study of the locally breed chicken brain showed that they are irregular in shape and they consist of three basic parts, cerebral, cerebellum and medulla oblongata. The mean weight of the brain for ten chickens was 23.726±1.38292g. Cerebrum was triangular in shape with smooth surface due to the absence of gyrus and sulcus , Olfactory bulb was undeveloped .The mean of the length and the width of cerebral was 17.45mm, 20.74mm respectively. The cerebellum was located behind the transverse fissure , Vermis was situated at central of cerebellum and oval in shape.The mean length and width of cerebellum was 11.669mm ,8.6mm respectively.The mean length and width of medulla oblongata was 4.134mm,6.4 mm respectively, The optic lobe appeared large and oval in shape . The histological results revealed that the cerebral cortex constituted the gray matter which has six layers namely molecular layer, external granular layer, pyramidal or external pyramidal layer, internal granular layer, internal pyramidal layer and multiform layer. The medulla constitutes the white matter which has dens bundles of nerve fibers and galial nerve cell. The cerebellar cortex consists of three layers namely molecular layer, purkinje cells layer and internal granular layer. The histological cellular structure of medulla oblongata was arranged as nucleus and reticular fibers which give the form of three longitudinal pillars, the first pillar was situated at the median level of medulla oblongata which has a group of middle size neurons, the second pillar was situated at medial side of medulla oblongata which has a large size neuron and the third pillar was situated at the lateral side of medulla oblongata which has small neurons.