Phagocytosis, Complement & Oedema Flashcards
The immune system can be categorised into which 2 categories?
Innate (non-specific)
Adaptive (highly specific)
What are 2 branches of the innate immune system?
Mechanical/chemical barriers
Cellular (e.g phagocytosis, complement)
What are two branches of the adaptive immune system?
Cell-mediated (b and t cells)
Humoral (antibody mediated)
In phagocytosis the ingested pathogen is packaged into a..?
Phagosome
A phagosome fuses with which organelle to aid in digestion? What is the resulting complex called?
Fuses with a lysosome - formation of a phagolysosome
Digestion of a pathogen in phagocytosis can be done in which two ways?
Oxygen-dependent
Oxygen-independent
What is a residual body? What two things can happen to a residual body once it is formed?
Indigestible material produced in phagocytosis.
Either secreted by exocytosis or remain as granules in the cytoplasm.
What is opsonization?
Process of identifying the invading particle to the phagocyte for destruction
What are two methods of opsonization?
Binding of antibodies e.g. IgG
Binding of C3B (complement protein)
Name 3 functions of complement
Destroys cells
Helps in opsonization
Results in inflammation
The complement cascade can be activated by which 2 pathways?
Classical Pathway
Alternative Pathway
What happens at the beginning of the classical pathway?
C1 is activated when it binds to an antibody-antigen complex
What happens at the beginning of the alternative pathway?
C3b is activated when it reacts with antigens (e.g the bacteria cell wall)
After initiation of either the classical or alternative pathways what is the common sequence of events that follows?
After C3 activation;
1) Inflammation
2) Opsonization
3) Membrane attack complex formed —> cytolysis
What is oedema?
An accumulation of an excessive amount of watery fluid, in cells, tissues or serous cavities.
