- Medulla oblongata
- The base of the brain, which is formed by the enlarged top of the spinal cord. This part of the brain directly controls breathing, blood flow, and other essential functions.
* * *medulla ob·lon·ga·ta -.äb-.lȯŋ-'gät-ə n, pl medulla oblongatas or medullae ob·lon·ga·tae -'gät-ē, -'gä-.tī 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)
* * *the extension within the skull of the upper end of the spinal cord, forming the lowest part of the brainstem. Besides forming the major pathway for nerve impulses entering and leaving the skull, the medulla contains centres that are responsible for the regulation of the heart and blood vessels, respiration, salivation, and swallowing. cranial nerves VI-XII leave the brain in this region.
* * *TA alternative for myelencephalon; the truncated cone of nerve tissue continuous above with the pons and below with the spinal cord. It lies anterior to the cerebellum, and the upper part of its posterior surface forms the floor of the lower part of the fourth ventricle; it contains ascending and descending tracts, and important collections of nerve cells that deal with vital functions, such as respiration, circulation, and special senses. Called also bulb of rhombencephalon, and bulbus rhombencephali [TA alternative]. See also brainstem.
Medical dictionary. 2011.