Immunology

Question 0

At what gestation does the fetus produce IgM, IgG and IgA

Answer 0

IgM at 11 weeks
IgG at 17 weeks
IgA at 30 weeks

Question 1

What immunoglobulins are small enough to cross the placenta

Answer 1

IgG only (smallest) 
IgA, IgD, IgE and IgM are too large

Question 2

What infective organisms contain no nucleic acids

Answer 2

Prion proteins

Question 3

Is HIV an RNA or DNA virus

Answer 3

RNA

Lentivirus class

Question 4

What is a type 1 hypersensitivity reaction

Answer 4

Allergic reaction

Question 5

What mediates a type 1 hypersensitivity (allergic) reaction

Answer 5

IgE

Question 6

What occurs in a type 1 hypersensitivity (allergic) reaction

Answer 6

Antigens ingested by antigen presenting cells (dendritic + B cells)
Presented to naive helper T cells
Via major histocompatibility complex
These Th0 cells differentiate into Th2 and produce IL4.
These cytokines act on B cells causing differentiation to plasma cells that produce IgE.
IgE binds to mast cells, activated eosinophils and basophils causing degranulation.
Releasing histamine, enzymes and more cytokines

Question 7

What cytokines are involved in a type 1 hypersensitivity reaction

Answer 7

Derivatives of arachadonic acid
Leukotrienes, produced via lipoxygenase pathway
Prostaglandins via the cycloxygenase pathway

Question 8

Where is IgA produced

Answer 8

Plasma cells near mucosal surfaces

Found in tears sweat, lung, gut, urine.