ANS part 3 (adrenergic receptors) Flashcards
which target organs of the SYMPATHETIC nervous system DO NOT have adrenergic receptors on the surface?
sweat glands - have muscarinic
the adrenal medulla - has nicotinic
what are the three catecholamines that are produced in the adrenal cortex?
adrenaline, noradrenaline and dopamine
what is the rate limiting step in the production of catecholamines in the adrenal medulla?
the transformation of tyrosine to DOPA decarboxylase by TYROSINE HYDROXYLASE
what inhibits tyrosine hydroxyls?
catecholamines
how do amphetamines affect noradrenergic neurons?
they increase the release of noradrenaline in synaptic vesicles
where are alpha 1 adrenergic receptors located?
mainly cardiovascular - on arteries and arterioles
smooth muscle - mainly GI and GU sphincters
where are beta 2 adrenergic receptors located?
mainly on the heart
also on kidneys
where are beta 2 adrenergic receptors located?
mainly lungs
visceral smooth muscle
skeletal muscle
what is the effect of stimulating the alpha 1 adrenergic receptors?
vasoconstriction - increases cardiac force and blood pressure
constricts GI and GU sphincter muscles
what is the effect of stimulating beta 1 receptors?
increases cardiac force and rate
increases renin release from kidneys - increases fluid retention and blood volume
what is the effect of stimulating beta 2 receptors?
bronchodilation, relaxation of visceral smooth muscle, vasodilation, skeletal muscle tremors
which adrenergic receptors does noradrenaline act on as an agonist?
alpha 1 and beta 1
which adrenergic receptors does adrenaline act on as an agonist?
on all of them
which adrenergic receptors does phenylephrine act on as an agonist?
alpha 1 only
which adrenergic receptors does salbutamol and salmeterol act on as an agonist
mainly beta 2 (some on beta 1) (used to treat asthma and to relax smooth muscle (e.g. to delay premature labour))
