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: TMJ is a medical problem which (like most medical problems) has multiple causes such as: Pre-existing bite problems. Muscle strain or jaw imbalances. Trauma to the jaw and even neck areas. Whiplash can even lead to a TMJ problem as the head tends to hyper-extend from the jaw during the sudden movements and could result in dislocation, or other injury. It can arise due to problems with your bite, muscle strain or imbalances, or damage to tissues in the head, neck and facial area. Displacement of the disk in your TMJ can be a permanent condition which may be controlled with proper care.