Module 7: Responses to Pathogens Flashcards
(14 cards)
What is one of the first responses to infection?
Inflammation.
What is the complement system?
A series of biochemical reactions that occurs during pathogen invasion and these reactions have the capability of killing pathogens by antibodies.
How is the complement system activated in humans?
In humans, this response is activated by complement binding to antibodies that have attached to these microbes or the binding of complement proteins to carbohydrates on the surfaces of microbes.
What are the important phases involved in the complement system?
Opsonisation, chemotaxis, cell lysis, and agglutination.
What is opsonisation?
Opsonisation is a process in which foreign particles are marked for phagocytosis.
What is chemotaxis?
Chemotaxis is the attraction and movement of macrophages to a chemical signal.
What is cell lysis?
The breaking down or destruction of the membrane of a cell.
What is agglutination?
Agglutination uses antibodies to cluster and bind pathogens together.
What role does agglutination play in the complement system?
By bringing as many pathogens together in the same area, the cells of the immune system can mount an attack and weaken the infection.
What role does cell lysis play in the complement system?
The proteins of the complement system puncture the membranes of foreign cells, destroying the integrity of the pathogen and weakening their ability to proliferate, putting a stop in spreading infection.
What role does chemotaxis play in the complement system?
By bringing immune cells to an area with identified pathogens, it improves the likelihood that the threats will be destroyed and the infection will be treated.
How is chemotaxis mediated?
This process is mediated by cytokines and chemokines to attract macrophages and neutrophils to the site of infection, ensuring that pathogens in the area will be destroyed.
What role does opsonisation play in the complement system?
All of the pathways require an antigen to signal that there is a threat present.
Opsonisation tags infected cells and identifies circulating pathogens expressing the same antigens.
How is the complement system activated?
By complement binding to antibodies that have attached to these microbes or the binding of complement proteins to carbohydrates on the surfaces of microbes. This recognition signal triggers a rapid killing response and the speed of the response is a result of signal amplification that occurs after sequential proteolytic activation of complement molecules, which are also proteases.
