Brainscape's Knowledge GenomeTM

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


See full index

medical science 202 > Lecture 12 > Flashcards

Lecture 12 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards USMLE® Step 1 flashcards
1
Q

classes of antibodies

A

IgM, IgG, IgA, IgD, IgE

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

what differences are the 5 classes of antibodies based on

A

the heavy chains they contain

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

types of light chains

A

kappa, lambda

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

types of heavy chains and their corresponding antibody class

A

mu - IgM, gamma - IgG, alpha - IgA, delta - IgD, epsilon - IgE

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

which antibody class has the largest antibodies, and how many antibody units (subunits) are there?

A

IgM, 5 (pentamer)

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

how many antigens can IgM bind?

A

10 (2 per variable region)

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

What effect does the size of IgM molecules have on its permeability?

A

less permeable as molecules are large, thus confined to bloodstream and lymphatics and doesn’t cross the placenta

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

What’s the first antibody class to be produced in the primary antibody response?

A

IgM (present in early infections), appears ~20weeks gestation

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

function of IgM antibodies

A

agglutination (clotting of cells, e.g. RBCs) and complement activation (can bind 5 C1q molecules and activate complement- thus making it important in the classical pathway)

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

what type of pathogenic spreading is IgM important in?

A

blood-borne spread of antigenically-complex infectious organisms, e.g. bacteria

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

what proportion of the total immunoglobulin pool is IgM?

A

10%

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

how many subunits does IgG have?

A

1 (small monomer)

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

what proportion of the total immunoglobulin pool is IgG?

A

70-75%

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

which antibody is the most important in foetal and neonatal immunity and what physiological property enables this?

A

IgG (only antibody class to readily diffuse across the maternal-fetal placenta and into extravascular spaces) due to its small size

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

important functions of IgG

A

neutralisation, complement activation, opsonisation and ADCC (potent antibody antitoxin), barrier against virus infections - strongly bound by phagocytic cells

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

Where is IgA found?

A

places with epithelial secretions, esp. sero-mucus secretions, e.g. saliva, tracheobronchial secretions, colostrum, milk and genitourinary secretions, mucus in G.I. tract

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

what physiological factor protects IgA from secretions?

A

IgA dimerises to protect it from secretions in the G.I. tract - it can also exist as a monomer

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

what proportion of the total immunoglobulin pool is IgA?

A

15-20%

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

main function of IgA

A

protection of external body surfaces by preventing potentially harmful material getting into the body through the gut, resp. tract and genitourinary tract

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

where is IgD predominantly found?

A

in the membrane of naive B cells

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

functions of IgD

A

activation of naive B cells through antigen binding (triggering receptor)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Abundance of IgD and IgE in blood

A

trace amounts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

When does the concentration of IgE rise?

A

during allergy and some parasitic infections

24
Q

where is IgE found, what cells does it bind to and via what receptors?

A

skin and airways, on the surface of mast cells and bound via Fc-epsilon-R’s

25
Q

symptoms which can occur when allergens bind to basophil-associated IgE

A

asthma, allergies or anaphylaxis

26
Q

what type of immunity is mediated by antibodies

A

humoral immunity

27
Q

what type of immunity is mediated by T-lymphocytes

A

cell-mediated immunity (CMI)

28
Q

what type of antigens are the antibodies of B lymphocytes most effective against and what type of immunity is this?

A

extracellular antigens, e.g. virus particles, extracellular bacteria and toxins - humoral immunity

29
Q

what type of antigens are T lymphocytes most effective against, what type of immunity is this?

A

intracellular antigens (antigens expressed on the surface of the body’s own cells - no antibodies), Cell-mediated immunity

30
Q

what are some examples of the sources of antigens which trigger cell-mediated immunity?

A

products of an infection within the cell (e.g. virus infection), tissues transplanted from a genetically dissimilar individual (e.g. skin graft or organ transplant), changes in the metabolism of cells (e.g. tumour cells), external material which has been phagocytosed and broken down by the cell

31
Q

T cell antigen responses:

A

cytotoxic responses - kill cells that carry recognisable antigens on their surfaces
helper responses - produce cytokines (immunological hormones) that assist other cells to respond

32
Q

What surface receptors do all T cells have?

A

CD3, TCR (T cell receptors - interact with antigens, important for antigen specificity and recognition)

33
Q

What surface receptor do cytotoxic T cells have which helper T cells don’t?

A

CD8

34
Q

What surface receptor do helper T cells have which cytotoxic T cells don’t?

A

CD4

35
Q

How do T cells recognise antigens?

A

T cells can only recognise antigenic epitopes which are presented to them on the surface of cells by Major Histocompatibility Complex determinants (MHCs)

36
Q

what types of chains make TCR’s?

A

alpha and beta

37
Q

What specialised structures are recognised in graft rejection and what is their function?

A

Major Histocompatibility Complex (MHC)/MHC genes, MHC structures present fragments of antigens to lymphocytes (T not B)

38
Q

Class 1 MHC proteins

A

HLA-A, HLA-B, HLA-C in humans, found on virtually all nucleated cells in the body (not on RBCs)

39
Q

Where are MHC class 1 proteins found?

A

On cytotoxic cells

40
Q

Where are MHC class 2 proteins found?

A

On helper T cells

41
Q

Class 1 MHC proteins

A

HLA-DP, HLA-DQ, HLA-DR in humans, only found on B-lymphocytes and specialised APCs (dendritic cells and macrophages)

42
Q

What is the expression of class 1 and class 2 genes and are they polymorphic (many different alleles exist within a species)?

A

co-dominant (expression of both parental alleles on cells). yes, they are polymorphic

43
Q

why is tissue transplant rejection so frequent, except between monozygotic twins (1 zygote splits into two twins)

A

HLA genes are highly polymorphic thus its extremely unlikely that two individuals will have the same set of HLA genes (unless they’re monozygotic twins)

44
Q

how does the immune system recognise tumours?

A

immune system detects an abnormal MHC presentation in tumour cells –> signals destruction
- a decrease in MHC signal triggers an immune response

45
Q

where are MHC proteins (structures) made?

A

ER

46
Q

when does an MHC protein obtain its antigen and specify to it?

A

before reaching the cell surface

47
Q

what type of chain do class 1 MHCs have that class 2 MHCs don’t?

A

Beta 2-microglobulin

48
Q

Antigenic peptide fragments (e.g. viruses or toxins) originating from within the cell is displayed on?

A

MHC Class 1 (HLA-A/B/C)

49
Q

Antigenic fragments phagocytosed by APCs (e.g. macrophages and B lymphocytes) and digested are displayed as what and on what structure?

A

peptide fragments, on MHC Class 2 (HLA-DP/DQ/DR)

50
Q

What T cell receptors interact with the antigen and MHC Class 1 presented to it? What is this interaction called?

A

TCR-alpha-beta, CD8 - this is called signal 1 input

51
Q

function of CD3

A

signalling mechanism

52
Q

are TCRs different on each T-cell clone, if so why?

A

yes, to provide high variability to recognise many different antigens

53
Q

primary what MHC class activates cytotoxic t cell precursors?

A

MHC Class 1

54
Q

what cytokines are sent to antigen-sensitive cytotoxic T lymphocyte precursors (CTLPs) by helper T cells?

A

IL-2

55
Q

where does T cell clonal activation and expansion occur?

A

secondary lymphoid organs

medical science 202 (10 decks)

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