Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Uncategorized > Chapter 17 > Flashcards

Chapter 17 Flashcards

1
Q

innate immunity

A

present at birth; nonspecific; no memory; rapid; halts infections; activated by interaction btw TLR (toll-like receptor) on cells in the body with PAMPs (pathogen-associated molecular patterns) on pathogens, which leads to infection.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

adaptive immunity

A

acquired after exposure; specific; has memory; slower; clears infetion; activated by dendritic cells which sense the signal from innate immunity, activates T cells, which initiate adaptive immunity that leads to formation of antibodies and killer cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

B lymphocytes

A

arise and mature in bone marrow; involved in humoral immune responses (antibody immunity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

T lymphocytes

A

Arise in bone marrow, migrate to and mature in thymus, involved in cell-mediated immune responses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

thymus

A

location of T cell maturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

bone marrow

A

location of B & T cell production, B cell maturation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

antigen

A

sometimes interchangeable with immunogen. They are able to bind with specific antibodies; however, may or may not stimulate immune responses. Mostly proteins or large polysaccharides. Often components of invading microbes such as capsules, cell walls, flagella, fimbrae, and toxins of bacteria; the coats of viruses; surfaces of other types of microbes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

immunogen

A

can stimulate specific immune responses. Good: protein & polysaccharides. Poor: lipids, nucleic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

epitope/antigenic determinants

A

region on antigen which antibody recognizes and interacts with.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

hapten

A

small, simple molecules that are not immunogenic (do not stimulate immune response) unless combined with other miolecules; they may be recognized and bound by specific antibodies.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

antibody

A

globular proteins (protein family with a compact globular form) - also called immunoglobins (Ig). Soluble proteins produced in response to immunogens and bind with specific antigens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Structure of antibody: heavy & light chain, bridge, shape

A

has 2 heavy chains and 2 identical light chains, linked by disulfide bridges; forms a Y-shaped molecule.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Structure of antibody: constant region

A

lower parts of the 2 arms and the stem of the Y; same for all antibodies of the same class.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Structure of antibody: variable region

A

top portion of the 2 arms of the Y; has the antigen-binding sites that bind to epitopes; variable regions carry from antibody to antibody. Each Y-shaped molecule has 2 antigen-binding sites

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Structure of antibody: variable region - antigen-binding site

A

formed by the heavy chains and the light chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

IgG

A

80%, most abundant in serum. Monomer; can cross placenta and protect fetus & newborns; enhances phagocytosis, neutralizes toxins & viruses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

IgM

A

Pentamer structure; effective in causing agglutination (blood type test); mostly in blood; stays on B cell surface as receptor; first class of antibodies produced in primary response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

IgA

A

Most abundant in the body - May be dimer or monomer; in secretions such as mucous, saliva, milk; prevent attachment of pathogens to mucousal surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

IgD

A

Monomer, on B cell surface; functions in initiating immune response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

IgE

A

Monomer; bound to mast cells and basophil through their Fc (stem) regions; involved in allergic responses; increases during allergic reactions & parasitic infections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Role of B cells in humoral immunity

A

antibodies are effective against pathogens that are circulating in the body, such as viruses and bacteria

22
Q

B cell activation

  1. Receptor
  2. Antigen
  3. MHC Class II
  4. Th cell > cytokines > B cells
A

The B cell receptors (mostly IgM and IgD) recognize and bind to one particular epitope on antigen.

Antigen is engulfed and processed, fragmented.

MHC Class II (major histocompatibility complex) in the B cell bind to a fragment of antigen and display it on B cell surface.

T(h) cell receptor recognizes and interacts with the antigen-MHC Class II complex and is activated to produce cytokines, which activates B cells.

23
Q

B cell activation: Clonal selection

A

Only one of the B cells with the receptors that recognize the particular epitope

24
Q

B cell activation: MHC class II

A

Binds to a fragment of antigen and display it on B cell surface.

25
Q

B cell activation: T(h) cell receptor

A

Recognizes and interacts with the antigen-MHC Class II complex and is activated to produce cytokines, which activates B cells.

26
Q

Clonal expansion

A

activated B cells proliferate into a large clone of cells, which differentiate into plasma cells and memory cells. Each clone of B cells has the same specificity and only recognizes one specific antigen. Initial antibodies produced are IgM

27
Q

Clonal expansion: plasma cells

A

antibody-producing cells; in general, short-lived.

28
Q

Clonal expansion: memory cells

A

responsible for the faster, stronger secondary response; long-lived

29
Q

Clonal expansion: T-dependent antigens

A

antigens that require help of T(h) cell for antibody production

30
Q

Clonal expansion: T-independent antigen

A

Antigens that directly stimulate B cells to produce antibodies without the help of T(h) cell, characterized by repeating subunits, such as polysaccharides; provoke a weaker immune response than T-dependent antigens; no memory cells are generated.

31
Q

Functions of antibodies: agglutination

A

basic monomer antibody (IgG), has 2 antigen-binding sites; can bind to 2 antigens; causes antigens to clump together, become insoluble, and precipitate; IgM has 10 antigen-binding sites (pentamer) and is a more effective aggluntanating molecule than IgG.

32
Q

Functions of antibodies: opsonization

A

antibodies stimulate phagocytosis by binding to the antigen, such as the surface of a bacterial cell

33
Q

Functions of antibodies: neutralization

A

antibodies block the activities of antigens, such as microbes and toxins by binding to them, preventing their attachment to the host cells

34
Q

Functions of antibodies: activation of complement system

A

with the arms (antigen-binding sites) bound to the antigens, antibodies bind to the complement molecules via the stem region (Fc), activate a cascade of reactions by the complement system.

35
Q

Functions of antibodies: antibody-dependent cell-mediated cytotoxicity

A

antibodies coat target cell (such as a worm), then macrophages, eosinophils, and the NK cells bind to the stem region (Fc) of antibodies. These cells of immune system then secrete substance to lyse the target cell.

36
Q

Cellular immunity

A

protective function of immunization is associated with cells (CD4 cells, helper T cells)

37
Q

humoral immunity

A

protective function of immunization is found in the humor (cell-free bodily fluid/serum)

38
Q

Classes of T cells: T helper cells

A

CD4+ T cells— recognize foreign antigen presented by MHC Class II on APCs (antigen presenting cells: macrophage, dendritic cell, B cell); activated T(h) cells produce cytokines that play roles in B cell activation, allergic reaction, inflammation, etc.

39
Q

Classes of T cells: T cytotoxic cells

A

CD8+ cells —recognize foreign antigen presented by MHC class I on APCs; activated Tc cells produce perforin and granzyme (pore-forming protein, protease that digests proteins) that lead to apoptosis (cell death) of targeted cells

40
Q

Classes of T cells: T regulatory cells

A

formerly called T suppressor cells; CD4+ cells that also carry CD25; T(r) cells keep adaptive immunity in check; thus, prevent autoimmune disease, control inflammatory response, avoid targeting normal flora.

41
Q

Antigen-presenting cells (APCs)

A

engulf a foreign antigen (pathogen) in tissue, process it, and present the antigen to T cells in lymph nodes or lymphoid tissues

42
Q

APCs: B cells

A

Receptors (mostly IgM and IgD) recognize and bind to one particular epitode on antigen.

43
Q

APCs: Dentritic cells

A

Can be found in lymph nodes, spleen, thymus, blood, skin, various tissues except brain; engulf pathogens in tissues and transport them to lymph nodes where the degraded fragments of pathogen are presented to T cells; dentritic cells are the principle APCs to induce T cell responses

44
Q

APCs: macrophages

A

Involved in phagocytosis as discussed previously; take up and present the antigen to T cells

45
Q

NK characteristics & role

A

innate; no specificity; need not to be stimulated by antigen; destroy virus-infected cells, cancer cells, parasites; kill target cell that does not express MHC class I self-antigens

46
Q

Adaptive immunity: Naturally aquired active immunity

A

immunity conferred when person is infected with pathogens and recovered – may last long time, even a life time (measles)

47
Q

Adaptive immunity: Naturally acquired passive immunity

A

transfer of antibodies from a mother to her infant through placenta or breast milk, may last weeks or months

48
Q

Adaptive immunity: Artificially acquired active immunity

A

result of vaccination, which is the introduction of antigens into the body; ex: killed/live weakened pathogens or inactivated bacterial toxins; provoke the body’s immune response, long lasting protection

49
Q

Adaptive immunity: Artificially acquired passive immunity

A

injection of antibodies into the body; immediate yet short-lived protection, only lasts a few weeks.

50
Q

Active immunity

A

person’s immune system responds after exposed to antigen

51
Q

Passive immunity

A

person obtains antibodies produced by others

Uncategorized (24 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions