Medulla oblongata the medulla as part of the primordial reptilian brain is confirmed by its disproportionate size in modern reptiles such as the crocodile, alligator, and monitor lizard. Medulla oblongata The medulla oblongata (or medulla) is located in the brainstem, anterior and partially inferior to the cerebellum. It is a cone-shaped neuronal mass responsible for autonomic (involuntary) functions ranging from vomiting to sneezing. The medulla contains the cardiac, respiratory, vomiting and vasomotor centers and therefore deals with the autonomic functions of breathing, heart rate and blood pressure. During embryonic development the medulla oblongata develops from the myelencephalon. The myelencephalon is a secondary
Medulla (hair) Medulla (hair) The medulla is the innermost layer of the hair shaft. This nearly invisible layer is the most soft and fragile, and serves as the pith or marrow of the hair. Scientists are still uncertain about the exact role of the medulla, but they speculate that it is primarily an extension that is more prominent in depigmented (grey or white) hair Human hair is unique in that its medullary index (the fraction of the hair shaft's diameter that the medulla occupies) is very small: generally less than 1/3. Other species will have much larger ratios, usually at least 1/2.