Cork and cork cambium (cork producing cell layer) are external Cortex-this is the primary tissue of the plant stem Phloem & Xylem are the inner most part and are concerned with carrying fluid and nutrients up and down the plant. Source(s): http://en.wikipedia.org/wiki/Bark. Orinoco Â· 9 years ago.
Malocclusion and bruxism are the most common causes of TMJ disorders. 1  Emotional stress is often the underlying cause of a TMJ disorder, as it can contribute to people either consciously or unconsciously tightening facial and jaw muscles and grinding or clenching their teeth.
Causes of TMJ Symptoms. TMJ symptoms are usually caused by spasms or charley horses, in the muscles of the head, neck, shoulders and back. The spasms are most commonly triggered by: Misalignment (malocclusion) between the way the teeth fit together and the way the temporomandibular or jaw joint wants them to fit.