resp pharmacology quick Flashcards
what does ACh on M3 receptors in the airway cause
Gq
stimulates phospholipase C
contraction
what does adrenaline on B2 receptors in airway cause
Gs stimulates adenylyl cyclase ATP --> cAMP --> PKA PKA phosphorylates \+ inhibits MLCK \+ stimulates myosin phosphatase relaxation
how does calcium initiate relaxation in a SMC
joins with calmodulin to form Ca2+-calmodulin
what does ca2+-calmodulin do
converts inactive MLCK into active MLCK
what does active MLCK do
converts inactive myosin cross bridge into phosphorylated myosin cross bridge (binds actin)
phosphorylation of regulatory MLC in the presence of elevated intracellular Ca2+ and ATP —->
contraction
dephosphorylation of MLC by myosin phosphatase —>
relaxation
in the presence of elevated intracellular Ca2+, what is greater - the rate of phosphorylation or the rate of dephosphorylation
rate of phosphorylation
true/false
relaxation requires return of intracellular Ca2+ to basal level
true - primary and secondary active transport
what does myosin light chain kinase do
dephosphorylated inactive MLC —> phosphorylated active MLC
relaxation —> contraction
what does myosin phosphatase do
phosphorylated active MLC —> dephosphorylated inactive MLC
contraction —> relaxation
give 5 characteristics of chronic asthma
increased mass of SM (hyperplasia and hypertrophy) accumulation of interstitial fluid increased secretion of mucus epithelial damage sub-epithelial fibrosis
what does epithelial damage cause
exposed sensory nerve endings (c-fibres) - hypersensitivity
what kind of hypersensitivity is asthma
Type 1 (delayed phase is type 4 but in general type 1)
what is the immediate phase of asthma
bronchoconstriction - hyperresponsiveness
what is the delayed phase of asthma
inflammation
what happens when a non-atopic individual encounters an allergen
phagocytosis of allergen by dendritic cell
low level Th1 response
what kind of immunity is it when a non-atopic individual meets an allergen
cell mediated
IgG and macrophages
what happens when an atopic person encounters an allergen
phagocytosis by dendritic cell
strong Th2 response
what kind of immunity is it when an atopic individual meets an allergen
anti-body mediated
IgE
what happens in severe asthma
Th1 also contributes
how does the antigen presenting cell present to Th cells
MHC class II
what does Th2 produce that activates B cells
IL4
also by binding to them
what do the activated B cells do
mature to plasma cells that secrete IgE
