Define nadir. nadir synonyms, nadir pronunciation, nadir translation, English dictionary definition of nadir. n. 1. Astronomy A point on the celestial sphere directly below the observer, diametrically opposite the zenith. 2. The lowest point: the nadir of their...
Annular tear â definition and causes. By Michael Perry, M.D. An annular tear is one of the most common degenerative spine conditions that develop with the natural aging process of the spine. In fact, many people over the age of 50 have an annular tear and never know it.
But when an annular tear or annular fissure does occur, the fibers either separate from one another or are severed from their place of insertion on the nearby spinal bone. A tear may also be seen as break through the fibers of one or more of the layers. Annular tears sometimes lead to herniated discs.