Causes of facet disease. Facet disease may arise when the cartilage in a facet joint is worn down as a result of aging, injury or wear and tear. This type of spinal damage can be attributed to arthritis, work, overuse or an injury sustained in an accident.acet disease occurs when a facet joint degenerates. While this can take place at any level of the spine, it most commonly affects the lumbar (lower spine) region. 1  Facet arthritis. 2  Facet joint syndrome. 3  Facet disease.
The raw materials of photosynthesis, water and carbon dioxide, enter the cells of the leaf, and the products of photosynthesis, sugar and oxygen, leave the leaf. Cross section of a leaf, showing the anatomical features important to the study of photosynthesis: stoma, guard cell, mesophyll cells, and vein.
The experiments showed that the O2 from plants was labeled oxygen-18 only if water was the source of the tracer (experiment 1). If the oxygen-18 was introduced to the plant in the form of CO2, the label did not turn up in the released O2 (experiment 2). A significant result of the shuffling of atoms during photosynthesis is the extraction of hydrogen from water and its incorporation into sugar.