mrcp part 1 clinical sciences Flashcards
(40 cards)
what type of cellular channel do local anaesthetic agents such as lidocaine work on
ion gated channels
what is a g protein coupled receptor
a drug binds to the target causing a sequence of events leading to the production of a secondary messenger
what drugs bind to g protein coupled receptors
opioids, adrenoreceptors (adrenoreceptors bind to catecholamines)
what are the adrenoreceptors
a1, a2, b1 and b2 receptors
1 receptors stimulate
2 receptors inhibit
what binds to tyrosine kinase receptors
endogenous hormones such as insulin
what binds to nuclear receptors
exogenous hormones such as levothyroxine and prednisolone
what mechanism of inheritance is found in a young male who developed bl loss of vision over one week with a central scotoma
lebers optic atrophy
mitochondrial inheritance
what is the pattern in mitochondrial inheritance
only via the maternal line, the sperm contributes no cytoplasm to the zygote
which type of conditions are inherited in an autosomal dominant
fashion
structural conditions
exceptions -
Hyperlipidaemia and hypokalaemic periodic paralysis are autosomal dominant
which type of conditions are autosomal recessive
generally metabolic conditions are recessive - including cystic fibrosis, CAH and albinism
exceptions
- ataxic telangiectasia and Frederichs ataxia are autosomal recessive
- G6PD and Hunters are x linked recessive
what is the inheritance of prader-willi and angelman
imprinting = gene deletion from one chromosome
if gene deleted from father - PW
if deleted from mother - AM
what are pcr reactions used for
detects a particular dna sequence
can detect mutated oncogenes, diagnosis of infection and prenatal diagnosis
uses a primer and Taq
what is a type 1 hypersensitivity reaction
allergic reaction
ige mediated
exposure to a previously sensitised substance causes mast cell degranulation
what is type 2 hypersensitivity and examples
cell mediated
igm and igg
antibodies already present attack cell surface antigens
AIHA, hyperacute gvhd, rheumatic fever, haemolytic transfusion reaction pemphigoid goodpastures etc
what is a type 3 hypersensitivity reaction
immune complex reaction
antibodies bind to soluble antigens this then causes reaction and inflammation at tissues
post strep gn, sle, serum sickness, HS pneumonia
type 4 sensitivity
delayed e.g. tuberculosis
type 5 hypersensivity
receptor based
myasthenia, graves
only recently added category
What is the innate immune system
Initial more generalised defence
macrophages recognise pathogen and signal further NT and macrophages and create inflammation with cytokine release
what is the adaptive immune system
more specialised immune system using t cells and b cells
what is il-1
tells the brain to cause fever, reduced appetite and lethargy
il-6 function
tells the liver to produce acute phase proteins
il-8 function
causes recruitment of further macrophages
il-2 and il-12
causes nk cell recruitment
how does adaptive immunity work with t cells
dendritic cells pick up antigens and display on cell surface
recognised by cd4 t cells which replicate into t helper cells
t helper cells
- become cd8 (cytotoxic t cells)
- attract b cells to produce plasma cells and ab
- release cytokines to recruit macrophages
