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.
Temporomandibular disorders (TMD) and temporomandibular joint disorders (TMJ) occur as a result of problems with the jaw, jaw joint and surrounding facial muscles that control chewing and moving the jaw. Learn what causes TMD and TMJ and how to prevent and treat them.