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.
Muscles attached to and surrounding the joint control the movement of the jaw, allowing us to talk, chew, yawn and perform other functions with our mouths. Many people experience TMJ disease, which causes facial pain; jaw clicking, popping and locking; earaches; headaches; bite problems; and other unpleasant symptoms.