1 Tuberculous pleuritis may occur in some people who have the lung disease from tuberculosis.  The pleural disease occurs from the rupture of a diseased area into the pleural space, the space between the lung and the lining of the chest and abdominal cavities.
The root apical meristem is a region of growth tissue near the tip of each root. The meristematic cells in this region grow in two directions, both backward toward the above-ground shoot and forward toward the tip of the root.
Apical meristems are the completely undifferentiated (indeterminate) meristems in a plant. These differentiate into three kinds of primary meristems. The primary meristems in turn produce the two secondary meristem types.These secondary meristems are also known as lateral meristems because they are involved in lateral growth. At the meristem summit, there is a small group of slowly dividing cells, which is commonly called the central zone.Cells of this zone have a stem cell function and are essential for meristem maintenance.hese secondary meristems are also known as lateral meristems because they are involved in lateral growth. At the meristem summit, there is a small group of slowly dividing cells, which is commonly called the central zone.