Shared Flashcard Set

Details

Micro 550 Test 1
N/A
27
Other
Undergraduate 4
10/13/2008

Additional Other Flashcards

 


 

Cards

Term

4 Natural barriers

Definition
  1. skin-sebaceous glands that produce oil and keeps skin pliable
  2. mucosal epithelium
  3. mucose
  4. ciliated cells that 'sweep' bacteria along
Term
Lethal Dose (LD 50) vs Infectious dose (ID 50)
Definition

LD 50-# that leads to death- causing 50% lethality/death

 

ID 50- # needed to infect (colonize)-causing 50% infection

Term
4 host barriers
Definition
  1. Mucose barriers- GI tract, eyes, pharynx, lungs
  2. lysozyme-can degrade bacterial cell wall
  3. interfuron-antiviral
  4. inflammatory-monocytes, neutrophils, leukocytes
Term
How are lungs kept sterile?
Definition
By the presence of macrophages
Term

extravasation

Definition

process by which cells migrate out of the capillary

Term
margination
Definition
process by which cells stick to the capillary
Term

Which cells are present at mucosal surfaces?

 

Definition
B, T, and macrophage cells (present in a pocket made by m-cell)
Term
how can bacteria travel from the lumen inside?
Definition

via m-cell

 

lumen: the canal, duct, or cavity of an organ, ie. the inside of a capillary

Term
Mannose-binding lectin
Definition
recognizes specific carbohydrates, esp. those on pathogens
Term
MAC- membrane attack complex
Definition
pokes holes in pathogen cell so contents spill out
Term
which kinds of cells are found in the lymph?
Definition
B, T, NK (all antigen specific)
Term
C3b receptor
Definition
binds to certain sugars on pathogens, it is part of complement and can work with IgG to hold bacteria close to the macrophage-->internalization of the pathogen
Term
transcytosed
Definition

process by which an antibody ie can be taken in on one side and release on the opposite side ie lumen-->other side

Term

cytokines

Definition
hormone-like messengers that facilitate communication between cells of the immune system
Term
what are b-cells and what do they produce?
Definition
white blood cells that are born in the marrow and become plasma B cells. IgG, IgA, IgD, IgE, IgM
Term
Most important facts about the Fc region of antibodies:
Definition
  • this tail binds to the receptors on cell surfaces ie macrophage
  • they determine Ab class (IgG vs IgA), which immune system cells it will bind to, and how it will funtion
Term
antibody/ neutralizing Ab
Definition
  • b cell (ie) receptor with antigen binding region (Fc) that searches for its cognate antigen
  • can bind to a virus while its still outside the cell (while its binding to its receptor) and prevent entry or replication once inside

 

Term
do all the receptors on a given B cell recognize the same cognate antigen?
Definition
yes!
Term

what happens when a b cell recognizes its cognate antigen?

Definition

proliferation- doubling in size and dividing over and over

these new cell will be clones that all recognize the same antigen

Term
Modular design of the b cell talks about the V, D, J, C gene segments. What is important about those segments?
Definition
there are different versions of each segment (called a module). to assemble a mature heavy chain gene, each b-cell chooses at random one of each kind of segment and pastes them together. the immature b cells are all alike with all the types of segments and the mature b cell chooses gene segments by recombination.
Term

*opsonization

Definition
process of Ab binding to the invador with their Fab regions, leaving their Fc tails available to bind to Fc receptors on the surface of cells like macrophages. This forms a bridge between the invader and the phagocyte, bringing the invader in close, and preparing it for phagocytosis
Term
MHC class I
Definition
present on most cells of the body, they function as "billboards" that inform killer T cells about what is going on inside other cells. ie by bringing viral peptide fragments to the surface of the infected cell to create a target
Term
MHC class II w/ process example
Definition
  • Only certain cells make this molecule and these cells are called antigen presenting cells (a macrophage is one).
  • after phagocytosis of a pathogen, the macrophage will load fragments of ingested proteins onto MHC II molecules for display, then helper T cells can scan the billboard for news of what's happening outside
Term
B and T cells are called:
Definition
lymphocytes...and must be activated in the adaptive immune system
Term
lymph nodes are the sites where:
Definition
B cells, T cells, APCs, and antigen all gather to communicate and activate
Supporting users have an ad free experience!