By respiratory system we usually mean the passages that transport incoming air to the lungs and to the microscopic air sacs called alveoli where gases are exchanged. The term respiration refers to the whole chain of processes from the inhalation of air to the use of oxygen in the cells. Index. Reference.
Phagocytes are the white blood cells that protect the body by eating (phagocytosing) dirt, bacteria and dead or dying cells. They are important for fighting infections. They are also important for becoming immune. Phagocytes are important in all animals and are very complex in vertebrates.
Function: As macrophages, monocytes do the job of phagocytosis (cell-eating) of any type of dead cell in the body, whether it is a somatic cell or a dead neutrophil. Because of their large size, they have the ability to digest large foreign particles in a wound unlike other types of white blood cells.