In mathematics, the Fibonacci numbers or Fibonacci series or Fibonacci sequence are the numbers in the following integer sequence: (sequence A000045 in OEIS) By definition, the first two numbers in the Fibonacci sequence are 0 and 1, and each subsequent number is the sum of the previous two.
Tight Junctions. Tight junctions are found predominantly in epithelial tissues, such as intestinal brush border. Water and other fluids must be prevented from leaking between adjacent cells, so that body fluids do not gradually seep across the intestinal lining.
Epithelia are classed as tight or leaky, depending on the ability of the tight junctions to prevent water and solute movement: 1  Tight epithelia have tight junctions that prevent most movement between cells. 2  Leaky epithelia do not have these tight junctions, or have less complex tight junctions.