An in-vitro model apparatus of a human spine and methods for detecting and analyzing substance distribution patterns therein. In one embodiment, the model apparatus includes a column body defining a passageway that substantially mimics the size, shape, and structure of an adult human spinal canal. Also included is a cord structure that may be located and anchored within the passageway. The cord structure substantially mimics the size, shape, and structure of an adult human spinal cord. For example, the cord structure may include connecting elements that resemble nerve roots, dentate ligaments, and the septum posticum of a human spine. The passageway of the model apparatus may be filled with a first fluid that simulates cerebro-spinal fluid (CSF), and a second fluid containing a drug (or simulated drug) may be introduced into the passageway, after which the drug's distribution within the passageway may be analyzed.