sympathetic systrm Flashcards
(18 cards)
what is this system about
fight flight fright freeze
blocking the parasympathetic NS e.g. with atropine poisoning leads to
revealing excess ‘sympathetic tone’ ??? kinda irrelevant icl
pre-ganglionic nerves emerge from where
the length of the spinal cord
most ganglia are in chains where
on either side of the spine
are pre-ganglionic neurons cholinergic
yes, but the transmitter switches in most post ganglionic neurons
life cycle of norepinepherine: unlike ACh, NE is degraded where
inside the cells:
- presynaptic metabolism via monoamine oxidase (MAO)
- postsynaptic metabolism via catechol-O-methyltransferase (COMT)
most sympathetic post ganglionic neurons release what?
noradrenaline
in the heart sympathetic neurons activate what receptors?
Beta 1 adrenagic receptors
in most other tissues sympathetic neurons activate what receptors
beta 2 adrenergic receptors
adrenaline is released from where
the adrenal medulla
what does this adrenaline bind to
mainly Beta 2 adrenergic receptors, which it reaches via the bloodstream
- exception and why
→ sweat glands: their sympathetic innervation is cholinergic and activates M3 receptors
sympathetic system target organs and the effect
eye (pupil dilation, a1 adrenergic)
salivary (viscous secretion - b2 adrenergic)
heart (increased rate and force of contraction (b1 adrenergic)
sweat glands (sweating, M3 muscarinic)
GI tract (B2 adrenergic: decreased motility), and (a1 adrenergic: constriction of sphincter)
Name ONE (1) a1 adrenergic agonist. Which tissues does it act on and for which conditions is it prescribed?
sudafedpe: nasal decongestant
- tissue : blood vessels (contracts)
- indication: congestion (constricts blood vessels in nasal passages)
Name ONE (1) a1 adrenergic antagonist. Which tissues does it act on and for which conditions is it prescribed?
prazosin hydrochloride
tissues: blood vessels (relaxes)
indication: hypertension, and reduces constriction in the urethra
Name ONE (1) B1 adrenergic antagonist. Which tissues does it act on and for which conditions is it prescribed?
atenolol
tissue: cardiac muscles (reduces activity)
indication: hypertension
some adrenergic ligands (They can bind to adrenergic receptors)
- atenolol
- propranolol
- adrenaline
Name ONE (1) B2 adrenergic agonist. Which tissues does it act on and for which conditions is it prescribed?
salbutamol
tissues: relaxes bronchial tubes (by blocking adrenaline from blood stream)
indication: asthma
Name ONE (1) muscarinic antagonist. Which tissues does it act on and for which conditions is it prescribed?
ipratropium bromide
- opens bronchial tissues, relaxing muscles and reducing mucus
indicated for asthma and COPD
