Immunoglobulins are proteins able to recognise antigens from pathogens and their toxic products. They either form B cell receptors or are secreted (antibodies) by differentiated B cells (plasmocytes). The main roles of antibodies are (i) recognise and neutralise pathogens (ii) activate other immune cells
For this, they must first recognize the pathogen through receptors [ PRRs: Pattern Recognition Receptors] (in the shape of a mouth on the gif). These receptors recognize molecular patterns of pathogens [PAMPs: Pathogen Associated Molecular Patterns]. Once the foreign body is recognized, the phagocytic cells must adhere to the pathogens and enclose it in order to ingest it. e dangers, at least most of the time.