Membrane attack complex group of complement

Membrane attack complex: group of complement
components (C5-C9) that bind to lipid bilayer of cell
membranes forming cylindrical channels (pores) of target
cells  allow influx of H2O  cell lysis & death
Kinin  Turned into bradykinin  pain, chemotaxis, & ↑ vascular
permeability/vasodilation
Coagulation Cascade  Activates kinin system via Factor XII (Hageman factor)
 Forms fibrin mesh  stops bleeding & traps microorganisms
b. Analyze the steps of the arachidonic acid pathway.
6. Analyze disorders which affect immune function.
c. Identify the etiology, pathophysiology and clinical manifestations of an
allergic immune response.
 Etiology:

o Immediate hypersensitivity response to an environmental
allergen
o Most reactions attributed to food, meds, pollen, etc.
 Patho:
o Initial exposure to allergen  IgE binds w/ allergen 
antigen-IgE complex  primes stage for reaction to occur
later
o Re-exposure to allergen  allergen (antigen) binds w/
previously formed antigen-IgE complex  complex detected
by mast cells  degranulation of complex  release of
histamine  triggers inflammatory cascade
 Clinical manifestations:
o Dependent on route the allergen entered body
 Urticaria
 Rhinitis
 Conjunctivitis
 Asthma
 Angioedema (idiopathic or r/t meds)
 Anaphylaxis (most severe):
 Itching
 Hives
 Angioedema
 N/V/D/abd cramps
 Wheezing
 Dyspnea
 Laryngeal edema
 Hypotension
 Shock
 Death
 Atopic D/O:
 Hay fever
 Asthma
 Eczema
 Urticaria
d. Differentiate between the processes of autoimmunity and alloimmunity.
 Autoimmunity:
o Disturbance in the immunologic tolerance of self-antigens
o Autoimmune diseases occur when the immune system reacts
against self-antigens to such a degree that the person’s own
tissues are damaged by autoantibodies or autoreactive T-cells
 Alloimmunity:
o Occurs when person mounts an immune response to another
member of the same species’ antigens/tissues
 E.g. ABO incompatibility, Rh incompatibility, blood
transfusion immunologic reaction, organ transplant
rejection