Communication between cells Flashcards
What is cell signalling?
Cell signalling is the communication between cells that allows effective coordination of a response.
How can a signal be detected?
In order to detect a signal, the target cell must have a cell surface receptor. B cells/T cells have receptors that are complementary to the foreign antigen.
What do a pathogen’s antigens do?
Pathogens have antigens which effectively say that they’re foreign.
What happens when lysosomes attack pathogens?
Lysosomes attack the pathogens. Pathogens often end up attached to the host plasma membrane, which act as a distress signal, and they act as markers to show infection - T killer cells.
What do Macrophages do and how is this special?
Macrophages in the lymph nodes, act as phagocytes, and engulf the pathogen. They do not fully digest it; instead they separate out antigens and put them on their cell surface membrane. Exposed on antigen-presenting cell - find lymphocytes for neutralisation.
What are cytokines?
Cytokines are chemical signals which act as instructions to target cells. Short disease, low concentration. They bind to specific membrane-bound receptors on target cells. Cause release of second messengers.
What do Macrophages do?
Macrophages release monokines that attract neutrophils; chemotaxis – movement towards a chemical.
What do Monokines do?
Macrophages release monokines that stimulate B cells to stimulate differentiation/release antibodies.
How are Interluekins released, and what do they do?
T cells/B cells and macrophages release interleukins – stimulate proliferation/differentiation of B/T cells.
What do Interferons do?
Many cells release interferons, inhibit virus replication, stimulate activity of T killer cells.
