In short, fiber is material that cannot be digested, and it acts like a sponge. It draws water from its surroundings, making it swell, which softens stool and adds bulk to it, which in turn helps it pass. Like coffee, some kinds of fiber (like beans) can contribute to constipation, so always drink plenty of water.
The immune system can distinguish between normal, healthy cells and unhealthy cells by recognizing a variety of danger cues called danger-associated molecular patterns (DAMPs). Cells may be unhealthy because of infection or because of cellular damage caused by non-infectious agents like sunburn or cancer.he immune system can distinguish between normal, healthy cells and unhealthy cells by recognizing a variety of danger cues called danger-associated molecular patterns (DAMPs). Cells may be unhealthy because of infection or because of cellular damage caused by non-infectious agents like sunburn or cancer.
Natural killer cells, or NK cells, are a part of the innate immune system which does not directly attack invading microbes. Instead, NK cells destroy compromised host cells, such as tumor cells or virus-infected cells. It recognises such cells by a condition known as missing self.hese are immune cells that engulf, i.e. phagocytose, pathogens or particles. To engulf a particle or pathogen, a phagocyte extends portions of its plasma membrane, wrapping the membrane around the particle until it is enveloped (i.e. the particle is now inside the cell).