n, pl  medulla oblongatas  or  medullae ob*lon*ga*tae   :  the somewhat pyramidal last part of the vertebrate brain developed from the posterior portion of the hindbrain and continuous posteriorly with the spinal cord, enclosing the fourth ventricle, and containing nuclei associated with most of the cranial nerves, major fiber tracts and decussations that link spinal with higher centers, and various centers mediating the control of involuntary vital functions (as respiration) .
 
 
 
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