Kaplan Biology: Chapter 8 Immune System Flashcards
innate immunity
nonspecific immunity in which defenses are always active against infection
slower-acting immune system in which defenses target a specific pathogen
adaptive immunity.
two types of adaptive immunity
1) humoral
2) cell-mediated.
spleen is where ___ cells are stored and activated. What do these cells turn into?
storage of B cells, which turn into PLASMA CELL to produce antibodies as part of adaptive immunity.
in addition to the spleen, where else can B cells get activated?
in the lymph nodes.
site of T cell maturation and storage
thymus
although different leukocytes get stored in different areas of the body, where do all leukocytes get originally produced?
in the bone marrow.
leukocytes are divided into ____ and ____
granulocytes and agranulocytes
both granulocytes and agranulocytes originate from ____ ___ cells
hematopoietic stem cells.
name the granulocytes and agranulocytes
granulocytes: neutophils, eosinophils, basophils
agranulocytes: lymphocytes(B cells, Natural killer cells), monocytes(macrophages)
What is a complement and what type of immunity does it play a role in?
involved in INNATE immunity. a complement is a type of protein that punch holes in the cell walls of bacteria, maknig them osmotically unstable.
____ are part of the innate immune system and protects against viruses by preventing DNA viral replication
interferons.
Difference between (+) sense and (-) sense viruses
Positive sense RNA viruses are single stranded RNA viruses whose RNA can function leads to protein synthesis from that mRNA.
Negative sense RNA viruses must first have their genome transcribed into positive sense RNA (usually by an RNA polymerase contained within the virion) and then can have that RNA turned into mRNA-> protein.
The main difference here is that positive sense RNA viruses have genetic material which can be directly converted into mRNA and then protein, while negative sense viruses usually have to carry an extra piece of cellular machinery that can turn their genome in a viable strand that can produce protein.
what is the positive sense strand in DNA? the negative sense?
the one that runs 5’ to 3’ is positive. the negative sense strand is 3’ to 5’. in a negative strand, complimentary positive 5’ to 3’ strand must be synthesized by the virus in order for it to be made into a protein.
HIV is a retrovirus with +sense ssRNA as its genome, which can be directly translated to the viral protein if necessary since it is oriented in the 5’ - 3’ direction. What must it do if it wants to incorporate itself into the host genome? What enzymes are involved?
it cannot incorporate directly because the virus is RNA, and it needs to become DNA.
it uses REVERSE TRANSCRIPTASE, which will read the 5’ to 3’ RNA and create complimentary DNA, from 5’ to 3’. Then, it makes another complimentary DNA strand from 5’ to 3’, flips it around, and creates a DOUBLE STRANDED DNA
then integrates creates sticky ends on the 3’ ends of the newly synthesized double stranded DNA and integrates it into the host genome.
which type of RNA (positive or negative) can be directly translated into a protein?
a positive sense RNA (one that is 5’ to 3’).
___ contains an MHC complex protein that holds pieces of invader to the cell surface after its been phagocytosed, displaying the antigen to other cells.
macrophages. phagocytoses an antigen and then pushes pieces of it out so it can be detected by Bcells, which will then form antibodies against it.
2 classes of MHC complexes
1) class 1, the endogenous pathway. binds to antigens from the inside of the macrophage ex/ from viruses
2) class 2, the exogenous pathway that involves phagocytosing the bacterial infection and displaying the antigens.
dendritic cells are a type of:
macrophage
a natural killer cell is a type of ____. what part of the immune system is it involved in and what does it do.
type of lymphocyte. induces apoptosis in virally infected by detecting the downregulation of MHCI complexes, which are normally seen in healthy cells
healthy cells exhibit ___ molecules. Viral infection or cancer can cause the reduction of MHCI expression, which triggers NK cells to induce apoptosis
exhibit MHC1 cells
granulocytes are from ___ stem cells
myeloid stem cells
most populous leukocyte
neutrophils.
role of neutrophiles
they phagocytose things and then opsonized (targeted for break down) when their antigens are marked with an antibody from a B cell.
_____ fight against parasites and release a large amount of histamines
eosinophils
basophil purpose
releases histamines and creates mast cells involved in allergy response
antibodies are produced as part of ____ immunity and are made by ___ cells
part of humoral immunity, made by B cells
How do Naive B cells produce antibodies?
B cells are not constantly active. They wait in the lymph nodes for their particular antigen to come along, when they are exposed to the antigen, B cells will proliferate and produce 2 types of daughter cells
1) plasma cells: produces antibodies
2) memory B cells: stay in the lymph node and away re exposure to the same antigen
isotype switching
cells can switch isoform of antibody they produce when they are stimulated by cytokines
cell mediated/cytotoxic immunity involves ___ cells
T cells
what is positive selection in terms of cell mediated immunity?
+ selection is the maturing only of cells that can respond to the presentation of an antigen on MHC
what is negative selection in terms of cell mediated immunity?
causing apoptosis in cells that are self-reactive: activated by proteins produced by the organism itself.
____ T Cells secretes lymphokines which can recruit other immune cells, activate macrophages and activate B cells
helper t cells
helper t cells are aka
CH4+ cells
____ T cells directly kills virally infected cells. What deactivates them?
cytotoxic T cells. aka CD8+. they get deactivated in the thymus.
___ T cells tone down the immune response once infection has been contained
regulatory
T cells and B cells both come ___ precursors
lymphocyte precursors
bacterial infections:
extracellular bacteria get trapped by ___ complex and get presented on the surface of macrophages. Then what?
MHCII complex. macrophages than produce cytokines which attract inflammatory cells like neutrophils and additional macrophages. Mast cells are also recruited.
macrophages travel to the nearest lymph node, where naive B cells are located. The naive B cells will produce antibodies and memory b cells. Helper T cells will also be activated
viral infections:
viral particles get trapped by the ___ complex and get presented on the surface of the macrophages. then whay?
what other part of the innate immune system is at play for combatting against viral infections?
MHCI complex ( the endogenous complex). CD8+ cells (killer t cells) recognize the MHCI complex and injects toxins into the cell to promote apoptosis.
interferons are also involved
T/F: Active immunity is very short lived
false. active immunity is the making of antibodies upon expsure to specific pathogens. it requires time to build, but it lasts long.
T/F: Passive immunity is short lived.
true. passive immunity is the transfer of antibodies to an individual through breastmilk or placenta. it is acquired immediately but it is short lived.
which bodily system is involved in B cell maturation?
lymphatic system. They host sites of B cell maturation in collections of GERMINAL CENTERS.
lymphocytes arise from ___ stem lines, whic later form __ and __ cells
lymphocytes arise from lymphoid cell lines (as opposed to myeloid stem lines that form granulocytes), and later form B and T cells. also forms natural killer cells.
