126 terms

DAT Bootcamp - Human Immune System

STUDY
PLAY
_____ are harmful microscopic enemies that can cause disease
pathogens
what are leukocytes?
white blood cells (WBCs)
leukocytes are produced by _____ in red bone marrow
hematopoiesis

(red bone marrow tends to concentrate at the end of long bones (epiphyses))
lymphocytes are special types of leukocytes that concentrate in _____ tissue
lymphatic
lymphocytes can produce _____ & _____
antibodies; cytokines
what are some examples of lymphocytes?
B and T cells
what are the 2 types of immune responses?
innate and adaptive
the _____ immune system is a quick, nonspecific immune response
innate
a human's outer barriers to infection (such as skin) are the first layer of _____ immunity
innate
what are some of the outer barriers, which are a part of innate immunity?
thick epidermis; dermis; hypodermis (subcutaneous); mucus membranes; sebaceous glands
pathogens are unable to penetrate which integument layers?
epidermis; dermis; hypodermis (subcutaneous)
mucus membranes in the skin function to secrete _____ and trap pathogens
lysozyme
lysozymes are antimicrobial protein enzymes found in tears, saliva, and mucous, which _____ break down bacterial _____
nonspecifically; cell walls
sebaceous glands of the skin secrete _____, which serves as physical barrier
oil (sebum)
the fatty acids in sebum are _____ & _____
antimicrobial; nonspecific
what are cilia?
hair-like projections that sweep away unwanted invaders
stomach acid is an _____ barrier of the innate immune system, which _____ kills microbes with low pH
internal; nonspecifically
_____ bacteria out-compete their more hostile relatives and are an _____ barrier to infection
symbiotic; internal
mast cells are a type of _____ that sits in tissues
leukocyte
injured tissue and mast cells work together to release _____
histamine
histamine dilates capillaries (and makes their walls more permeable) near injured vessels, which brings more blood to the injured area - why is this beneficial?
fluid and immune cells leak out to the site of injury

(inflammatory response)
what are the 5 signs associated with inflammation?
Swelling
Loss of function
Increased heat
Pain
Redness

(SLIPR)
heat is an inflammatory sign, which results from _____ and _____
dilation of capillaries; increased blood flow
_____ is an inflammatory sign, which occurs due to the dilation of capillaries
redness

(more blood = red color)
_____ is an inflammatory sign that occurs by permeable capillaries
swelling

(fluid accumulation)
_____ pain happens right at the time of injury, and it is caused by nerve endings
sharp
_____ pain is felt after the time of injury, and it is due to inflammation
slow, throbbing
what are the indirect outcomes of inflammation?
loss of function due to swelling and pain
_____ is a systemic response to hinder the growth of (or kill) pathogens
fever
when capillaries dilate during the inflammatory response, leukocytes tend to adhere to the endothelial cells that line the vessels - what is this called?
margination
_____ is the passage of leukocytes through the unruptured wall of a blood vessel during inflammation
diapedesis
what is chemotaxis?
the process of moving to a location in response to a chemical signal
what are the 5 types of leukocytes in order of abundance?
(Never Let Monkeys Eat Bananas)

Neutrophils
Lymphocytes
Monocytes/Macrophages
Eosinophils
Basophils
_____ are the most numerous leukocytes
Neutrophils (Never)
Neutrophils (Never) act as _____ in the _____ immune system
phagocytes; innate
which Lymphocytes (Let) are innate and which are adaptive?
natural killer (NK) cells = innate; B and T cells = adaptive
_____ cells are innate Lymphocytes (Let) that attack and kill virus-infected cells, as well as cancerous body cells
natural killer (NK)
natural killer (NK) cells are innate Lymphocytes (Let) that do not require _____
activation
NK cells are innate Lymphocytes (Let) that secrete _____ & _____ to fight enemies
perforin; granzymes

(NK cells (innate) and CD8/cytotoxic T cells (adaptive) are both Lymphocytes (Let) that secrete perforin and granzymes)
_____ is a protein that creates a pore to perforate pathogen membranes
perforin

(NK cells (innate) and CD8/cytotoxic T cells (adaptive) are both Lymphocytes (Let) that secrete perforin and granzymes)
granzymes are proteases, which stimulate apoptosis, which is useful for virally infected/cancerous cells
(NK cells (innate) and CD8/cytotoxic T cells (adaptive) are both Lymphocytes (Let) that secrete perforin and granzymes)
a _____ is an enzyme that breaks down proteins and peptides
protease
_____is programmed cell death
apoptosis
Monocytes (Monkeys) are a part of the _____ response
innate

(nonspecific)
Monocytes (Monkeys) are immature when they are in blood vessels; however, they mature into _____ once they cross over into an infected tissue via diapedesis
macrophages
macrophages are mature Monocytes (Monkeys) that act as phagocytes and function as _____ to activate adaptive immunity
antigen-presenting cells
Eosinophils (Eat) are a part of the _____ immune response
innate

(non-specific)
Eosinophils (Eat) contain _____ in their cytoplasm, which can be released to kill pathogens (especially effective on parasites)
granules
Basophils (Bananas) are the _____ numerous leukocyte
least
Basophils (Bananas) contain _____ (like Esoinophils) and have a similar function to _____
granules; mast cells
what are the 2 important components of Basophil (Bananas) granules?
histamine; heparin
_____ is a component of Basophil (Bananas) granules, which prevents blood from clotting too quickly
heparin
mast cells and Basophils (Bananas) are made in _____ and then leave to circulate in the _____
red bone marrow; blood
Basophils (Bananas) are _____ in the blood, while mast cells are _____ in the blood
mature; immature
dendritic cells use _____ to observe local environment
pinocytosis
pinocytosis is a type of endocytosis that is also known as _____
cellular drinking

(endo-/exocytosis are active transport mechanisms)
dendritic cells are part of the _____ immune system, but they travel to lymph nodes to activate _____ immunity
innate; adaptive

(dendritic cells are antigen presenting cells)
interferon is secreted by _____ cells
virus-infected
_____ binds to non-infected cells to warn/prepare for viral attack
interferon
interferon activates _____ cells, which further activates adaptive immunity
dendritic
complement system contains a group of _____ that help the immune cells battle pathogens
proteins
opsonization is a feature of the complement system - what does it do?
complement proteins coat the surface of an invader, making them more prone to phagocytosis
the complement proteins are activated by _____
IgG and IgM
what are the two mechanisms for complement system activation?
classical and alternative pathways

(don't memorize requirements for each)
what are 3 things the complement system can do when it is activated?
opsonization; stronger histamine release + more inflammation; membrane attack complex (MAC)
describe the effects of a membrane attack complex (MAC) created by the complement system:
poke holes in pathogen --> fluid and salts enter pathogen --> lysis
if innate immunity isn't sufficient to protect against pathogens, what joins?
adaptive immunity
_____ immunity is a specific immune response for specific antigens, and it has _____
adaptive; memory
an _____ is a marker that helps distinguish between self/non-self cells
antigen
how does the body distinguish between self and non-self cells (in addition to antigens)?
major histocompatibility complex (MHC)
all nucleated cells contain MHC class _____ molecules on their surface
1
antigen presenting cells contain both MHC class _____ & _____ molecules on their surface
1; 2
true or false - individuals contain unique MHC 1 molecules
true

exception: identical twins have the same MHC 1
what are the proteins of a MHC class 1 molecule?
alpha 1, 2, 3 and beta-microglobulin protein chains
what are the proteins of a MHC class 2 molecule?
alpha 1 and 2; beta 1 and 2
why do transplanet rejections occur?
different MHC 1 molecules will be labeled as a foreign antigen on the donor organ
transplant patients must take _____ on a life-long basis
immunosuppressants
in autoimmune diseases, the immune system attacks _____
self-cells
_____ act as a bridge between innate and adaptive immunity
antigen-presenting cells (APCs)
macrophages and dendritic cells are _____
antigen-presenting cells (APCs)
macrophages and dendritic cells contain MHC class _____ and _____ - why?
1; 2

they are antigen presenting cells (APCs)
a _____ is the section of an antigen that is recognized by immune cells
epitope
B and T cells are adaptive _____
Lymphocytes (Let)
what are the 3 main types of Lymphocytes (Let)?
NK cells (nnate); B and T cells (adaptive)
B cells stay and mature in the _____, while T cells go and mature in the _____
bone marrow; thymus
_____ are involved with antibody-mediated adaptive immunity (humoral immunity)
B cells
each B cell has 1 type of _____ that is specific for 1 type of antigen epitope
B cell receptor (BCR)
what can B cell receptors (BCRs) bind to?
free-floating antigens or antigens presented by APCs
what happens after a B cell binds to an antigen?
it becomes activated and then divides to make copies of itself
describe the clonal selection model for B cells
B cells have unique BCRs to specific antigens. If those antigens are present, only the B cells with the BCR for antigen binding will amplify
what are the 2 types of cells that B cells can differentiate into?
plasma cells or memory B cells
what are plasma B cells responsible for?
releasing antibodies called immunoglobulins;
plasma B cells circulate in the _____ and _____
blood; lymph
what is the difference between a B cell receptor (BCR) and an antibody?
structurally they are identical; however, a BCR is bound to the B cell membrane, while antibodies are freely floating immunoglobulins
what are 3 things antibodies can do after they are released into the humor (body fluid)
tag corresponding antigen for phagocytosis; coat the antigen in antibodies; activate the complement system
what is the shape/composition of an antibody (immunoglobulin)
Y-shaped, consisting of a light chain and a heavy chain linked through disulfide bonds
describe the function of the constant region on an antibody/immunoglobulin:
leads to the development of 5 major antibody/immunoglbulin classes

(IgM; IgA; IgE; IgD; IgG)
describe the function of the variable region on an antibody/immunoglobulin:
different amino acid sequence for different antigen binding
5 classes of antibodies (immunoglobulins)
(Me And Eve Don't Go)

IgM
IgA
IgE
IgD
IgG
IgM is a _____, and it is the _____ antibody
pentamer; largest
_____ is the 1st immunoglobulin made in response to an antigen
IgM
IgM activates the _____ (innate immunity)
complement system

(IgG also activates the complement system of innate immunity)
_____ is a dimer that is abundant in body secretions
IgA
IgA provides _____ immunity to newborns (breastmilk)
passive
IgA stops pathogens _____ before they enter circulation
externally
_____ is a monomer found on Basophils (Bananas) and mast cells
IgE
IgE is involved with _____ reaction
allergic
_____ is a monomer that is a part of the B cell receptor, and it activates Basophils (Bananas) and mast cells
IgD
what is the most abundant antibody in circulation?
IgG
IgG is a monomer, and it is the only immunoglobulin capable of _____ to provide _____ immunity
crossing the placenta; fetal passive
_____ works with _____ to trigger the complement system
IgG; IgM
_____ B cells have a long life, and they do not release antibodies
memory
memory B cells are the key to _____ because they have antigen memory
vaccinations
_____ are involved with cell-mediated adaptive immunity
T cells
T cells experience _____ because they have T cell receptors (TCRs) that are unique for specific antigens, much like B cells
clonal selection
T cell receptors (TCR)
binds to only one kind of antigen;
_____ release antibodies to attack pathogens, _____ attack patogens themselves after they are activated
B cells; T cells
_____ can recognize free floating antigens, but _____ need an antigen presenting cell
B cells; T cells
what happens if an antigen is presented to a TCR by MHC I?
activation to CD8 T cells
what are some similarities of CD8 T cells and NK cells?
both are Lymphocytes (Let) that release perforin and granzymes
what are some differences of CD8 T cells and NK cells?
NK cells are innate Lymphocytes (Let), so they react fast and non-specifically

CD8 cells are adaptive Lymphocytes (Let), so they react sepcifically (and slower)
what happens if an antigen is presented to a TCR by MHC II?
activation to CD4 T cells
helper T cells (CD4) assist both innate and adaptive immunity by releasing _____ to ramp up the immune response
cytokines
_____ are formed after an initial exposure to MHC I/II, and they quickly proliferate upon re-exposure to an antigen
memory T cells
describe passive immunity:
ready-made antibodies are given to an organism, either naturally or artificially

(organism does not make their own)
describe active immunity:
an organism makes their own antibodies either naturally or artificially