Test 1: lecture 3 alpha2 Flashcards
alpha 2 receptors are what type of receptors
g protein
⍺2 autoreceptors will cause the —
stop the release of NE
compare presynaptic and postsynaptic ⍺2 receptors
presynaptic ⍺2 autoreceptors : inhibit NE release
postsynaptic: cause release of NE
α-2A receptors located presynaptically on neurons in the — of the brain
LOCUS COERULEUS
controls sleep and awake (will cause sedation, analgesia, decreased sympathetic activity such as decreased HR and decreased BP)
a2 will first cause vessels outside the brain to vasoconstrict and decrease HR
if high BP then still in peripheral phase, if low BP then drug has made it into the brain
peripheral or central effect of a2 will cause decreased BP
central: will cause decreased HR and decreased BP
peripheral: causes vasoconstriction= higher BP and decreased HR
what type of animal requires much lower dose of xylazine IV
cattle
explain supraspinal analgesia
thalamus will tell spinal cord to chill
brain knows there is pain but if not actively using leg no need to freak out
when to treat with atropine
for central: decreased sympathetic tone: ↓BP, ↓HR and ↓CO
do not use for peripheral when ↑BP, ↓HR and ↓CO (caused by vasoconstriction of vascular smooth muscle)
how does a2 agonist effect respiratory in horses
will cause muscle relaxation
horses flare nostrils to breathe, if you relax these muscles will causes increased resistance and increased work
will decrease abduction of arytenoid cartilage and effect larynx
do not use in horses will COPD or airway obstructions
what happens to lungs of sheep with a2 agonist
macrophages cause damage to capillary endothelium and alveolar type I cells causing edema and hemorrhage
—, a2 agonist, use 1/10 equine dose in cattle
xylazine
what a2 agonist is used in small animal
Dexmedetomidine
can be reversed with antisedan (Atipamezole)
reversal for small animal ⍺2 agonist
Dexmedetomidine
can be reversed with antisedan (Atipamezole)
