immune

Question 1

what are antibodies also known as?

Answer 1

immunoglobulins

Question 2

where do antibodies comes from?

Answer 2

they’re secreted by b cells - specifically, by plasma cells in the blood stream

Question 3

what is the role of antibodies in the body?

Answer 3

to control and stop pathogens

to assist in the immune response

Question 4

how many classes of antibodies are there?

Answer 4

5

Question 5

which immunoglobulin is the main one found in blood, lymph, CSF and peritoneal fluid?

Answer 5

IGg

Question 6

what percentage of total serum proteins does IGg usually make up?

Answer 6

15% (a lot!)

Question 7

what is opsonisation?

Answer 7

coating of bacteria by the antibody

(assist in phagocytosis)

(one end of the antibody binds to receptors on the antigen; phagocytes have receptors for the other end of the antibody, so they bind to the antibody and then phagocytose the antigen)

Question 8

what is agglutination?

Answer 8

forms precipitate, makes antigen more soluble and makes them more easily phagocytised

Question 9

what is the only antibody that can pass through to the placenta?

Answer 9

IGg

Question 10

what is antibody-dependent cell-mediated cytotoxicity

Answer 10

a process by which IGg antibodies bind to receptor on tumor cells, marking them for NK cells which will release cytotoxins to destroy it

Question 11

how do IGg cells assist the immune response?

Answer 11

opsonisation,
agglutionation & precipitation,
neutralisation
activation of the complement sysytem

Question 12

what is neutralisation?

Answer 12

neutralisation of toxins by IGg, including tetanus, botulism, snake and scorpion venom

neutralisation of viruses - binds to epitopes, may prevent virus absoption and release

Question 13

describe IgG

Answer 13

‘memory’ antibody (80% of antibodies)

responsible for resistance against many viruses, bacteria and bacterial toxins

Smaller, can cross the placenta

Question 14

describe IgD

Answer 14

found in B cell surfaces, bind with antigens in ECF and plays a role in sensitising B cells

IgD is membrane-bound, is a marker of maturity in b cells, and the exact action is not perfectly understood

Question 15

describe IgA

Answer 15

found primarily in glandular secretions: mucus, tears, saliva, semen; but also in in blood

because it is commonly found in mucus, plays an important role in GI, respiratory and genital tracts
role is to attack pathogens before they gain access to internal tissues

Question 16

describe IgM

Answer 16

first one made after antigen encountered

IgM population declines as IgG population increases

Anti-A and anti-B antibodies responsible for agglutination of incompatible blood types are IgM

Question 17

describe IgE

Answer 17

active in allergies, protection from parasites

chain end binds to active sites on mast cells and basophils, with fab area ready to bind to antigen

Once bound to an antigen, mast cell releases histamine and accelerates inflammation