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.
At gap junctions, the intercellular space is between 2 and 4 nm and unit connexons in the membrane of each cell are aligned with one another. Gap junction channels formed from two identical hemichannels are called homotypic, while those with differing hemichannels are heterotypic.