Corpora quadrigemina

Transcription

The brainstem is the brain anatomical structure that links different parts of the central nervous system: the forebrain, the cerebellum and the spinal cord. The brainstem plays a vital role in the many essential functions that its nuclei regulate such as breathing and heart rate and even Consciousness. It is also a passageway to sensory and motor pathways and a pain control center The brainstem represents the emergence area of most cranial nerves We distinguish three parts of the brainstem : the midbrain, the pons and the medulla The midbrain or "mesencephalon" is the area of the brainstem that is directly connected to the forebrain through the cerebral peduncles behind these two peduncles we find the tegmentum with a hole in back side the cerebral aqueduct Also known as the aqueduct of Sylvius it connects the 3rd to the 4th ventricle on the back of The midbrain is the tectum with four colliculi where lie the reflex centers involving hearing and vision The Pons "AKA the pons Varolii" is the middle part of the brainstem It plays an important role in motor functions with its relay position between the forebrain and the cerebellum it also contributes to autonomous functions and facial sensitivity it containes the core and the emergence of the trigeminal nerve The Pons is connected to the cerebellum by the middle cerebellar peduncle It delimits the front face of the 4th ventricle The medulla oblongata is the portion of the brainstem between the pons and the spinal cord The medulla contains the olivary and a pair of pyramids that contain the corticospinal fibers of the pyramidal tract The medulla contains vital autonomic control centers for functions such as breathing, heart rate and many reflex functions vomiting, coughing, sneezing, and swallowing It ends at the bottom by the pyramidal decussation a crossing region of the corticospinal fibers