autonomic pharmacology 1 Flashcards
which neervous system has both central and perihperal components
autonomic
function of ans
mediates output from the CNS to the whole body except skeletal muscle as its voluntary
what does the ANS regulate
functions essential to human life that dont require conscious effort
contraction and relaxation of vascular and visceral smooth muscle
the heartbeat (including rate and force)
all exocrine and certain endocrine secretions
aspects of metabolism (particularly in liver and skeletal muscle)
modulation of the processes of the immune system
what is the ANS subdivided into
para and sympathetic and enteric
sympathetic ANS
Fight or flight
what does the motor ANS component comprise of
preganglionic and postganglionic fibres
parasympathetic
rest and digest
sympathetic transmitters
ach at pre and noradrenaline at post
parasympathetic transmitters
ach at both
receptors of noradrenaline
adrenoceptors
receptors of ach
cholinoceptors
first step of pathwya of action potential originating in CNS (sympa)
Travels to presynaptic terminal on preganglionic neuron
triggers Ca2+ entry
release of Ach by exocytosis
what is Ca2+ entried through
voltage gated calcium selective ion channels
second step of AP in CNS (sympa)
Ach binds to and opens ligand gated ion channels in postganglionic neurone
causes depolarization
APS propagate to presynaptic terminal of neurone
trigger Ca2+ entry
release of noradrenaline
last step of chemical transmission in ANS (sympa)
noradrenaline activates G protein coupled adrenoceptors in effector cell membrane to cause a cellular response via ion channels/ enzymes
difference in AP conduction in parasympathetic
Ach us always the transmitter at postganglionic neurones
activates g protein coupled muscarinic acetylchoine receptors in effector cell to cause cellular response via iion channels/ enzymes
non adrenergic non cholinergic transmission in sympathetic fibres
ATP and neuropeptide y (NPY)
non adrenergic non cholinergic transmission from parasympathetic fibres
nitric oxide and vasoactive intestinal peptide
are Ach and NA co released with a NANC co transmitter?
yes
agonist of cholinoceptors that are nicotinic or muscarinic
Acetylcholline
nicotinic ach receptors
ligand gated ion channels
activated by the plant alkaloid, nicotine
muscarinic ach receptors of effector cell
GPCRS
activated by plant alkaloid, muscarine
subtypes of muscarinic GPCRS
m1-5
most important subtypes in ANS
m1-3
endogenous agonists of GPCRS
NA and Ach
action of a1
vasoconstriction
action of a2
GI relaxation
action of b1
increases heart rate and force of contraction in atria and ventricles
action of b2
bronchodilation
action of b3
thermogenesis in skeletal muscle
which muscarinic cholinoceptors decraese heart rate and force in atria
m2
which m constricts bronchi, stimulates mucus production and increses intestinal motility
m3
which m contracts wall of bladder
m3
where do efferent signals travel
the body apart form skeletal musclee
where do afferent signals travel
to brain
