/äˌblôNGˈgätə/
Noun
1. The lower half of the brainstem. In discussions of neurology and similar contexts where no ambiguity will result, it is often referred to as simply the medulla. The medulla contains the cardiac, respiratory, vomiting and vasomotor centers and deals with autonomic, involuntary functions, such as breathing, heart rate and blood pressure. (wikipedia.org)
2. The lower portion of the brainstem. (wiktionary.org)
3. The part of the vertebrate brain that is continuous posteriorly with the spinal cord and that contains the centers controlling involuntary vital functions. (merriam-webster.com)
4. Lower or hindmost part of the brain; continuous with spinal cord. (wordnetweb.princeton.edu)
5. The continuation of the spinal cord within the skull, forming the lowest part of the brainstem and containing control centers for the heart and lungs. (Google Dictionary)
Word origin: From Latin medulla, literally “marrow,” also “pith of plants,” of unknown origin, perhaps related to or influenced by medius “middle.”