Assertion: medulla's sulcus | /r/HasProperty | narrow groove
Facets:
Source sentences:
text: The posterior median sulcus of medulla oblongata is a narrow groove; and exists only in the closed part of the medulla oblongata; it becomes gradually shallower from below upward, and finally ends about the middle of the medulla oblongata, where the central canal expands into the cavity of the fourth ventricle.