Gradient, chemotactic
Chapter: 2
Leukocytes are attracted along a chemical gradient. They have the ability to distinguish between a minute difference in concentration of the chemotactic agent at the front compared to the back of the cell body. Therefore they can orient themselves toward the source of the gradient and follow the increasingly strengthening chemical gradient until they encounter what is causing its production. There are three general sources of chemotactic factors: bacterial products (e.g.N-formylated peptides) activated plasma proteins and secretory products of cells.