Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
13 Cards in this Set
- Front
- Back
|
At which complement factor do all 3 complement pathways converge?
|
C5. Though C3 is present in all 3 complement cascades it does not mark a convergence point.
|
|
|
At which complement factor do all 3 complement pathways converge?
|
C5. Though C3 is present in all 3 complement cascades it does not mark a convergence point.
|
|
|
What are the roles of the unbound protein fragments of the complement pathways, namely C3a, C4a, and C5a?
|
All 3 cause mast cell degranulation, leading to an anaphylaxis like reaction. C5a also stimulates neutrophil chemotaxis and extravasation.
|
|
|
What is the role of the late factors of the complement cascade C5-C9?
|
Responsible for generating the membrane attack complex(MAC), which inserts pores into the microbes cell membrane. These pores disrupt the osmotic gradient maintained by the membrane, resulting in swelling andrupture of the microbe.
|
|
|
What are the 3 effector mechanisms by which complement fights infection?
|
C3b promotes phagocytosis through opsonization
MAC causes osmotic lysis of the microbes C3a, C4a, and C5a recruit leukocyte to areas of complement activation, thus secondarily stimulating various mechanisms of microbial immunity. |
|
|
What is the most commonly identified human complement deficiency?
|
C2 deficiency
|
|
|
C1 inhibitor inhibits the classical pathway of complement activation. What condition results from a deficiency of C1 inhibitor?
|
Hereditary angioedema is an autosomal dominant disease with edema in multiple organs, due to increased production of vasoactive C3a and C5a. If the larynx is involved, the outcome an be fatal.
|
|
|
Severe pyogenic(Staph/ Strep) respiratory ans sinus tract infections result from a deficiency in what complement factor?
|
C3
|
|
|
Deficiencies in the late factors of the complement cascade, C5-C9, result in susceptibility to wat specific microbes?
|
The Neisseria species of bacteria(Neisseria meningitidis and N. gonorrhea).
|
|
|
What is the role of decay accelerating factor(DAF) in the complement cascade?
|
DAF inhibits formation of C3 convertase. It displaces C2a from C4b in the classical and lectin pathways and Bb from C3b in the alternative pathway.
|
|
|
What condition results from a deficiency of delay accelerating factor(DAF) due to increased complement mediated hemolysis?
|
Paroxysmal nocturnal hemoglobinuria(PNH) is marked intermittent passing of dark hemoglobin rich urine upon waking(reflects nighttime pathology), which can lead to chronic anemia and venous thrombosis.
|
|
|
What is responsible for the specificity of the complement cascade to microbes and not host cells?
|
Regulatory proteins found on host cells but not microbes inhibit complement activation. Think of microbes as lacking the Off switch for complement mediated lysis.
|
|
|
Name 2 molecules that result in direct opsonization?
|
IgG and C3b
|
