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ANS NTs and drugs
Question | Answer |
---|---|
Glutamate | Major excitatory NT in CNS. |
Dopamine | Generally inhibitory |
Serotonin | High concentrations in brain, GIT, and blood platelets. |
GABA | MAJOR INHIBITORY w/in CNS |
Benzodiazepines act on GABA receptors, what do they do? | Agonist, they enhance the effect. |
What is the general effect of Nitric Oxide | Vasodilation. |
Where are Enkaphalins/endorphins found? What receptors do they bind with? What effect? | Found in GIT and brain. Bind to opioid receptors and modify pain signals. |
Where is Substance P found and what is its effect? | Intestines, peripheral nerves and CNS. Involved with peristalsis in GIT and pain signals in peripheral nerves. |
How is cholinergic NT activity most often ended? | Enzyme degradation (acetylcholinesterase) |
How is adrenergic NT activity ended? | Reuptake. |
What receptors does epi bind to and generally what is the effect? | Potent agonist on Alpha and Beta receptors. Vasopressor |
What are the effects of epi on the myocardium? | Systole is shorter (which inc's coronary blood flow), inc's contractility, inc's CO, work of the heart and O2 consumption |
How does epi effect the pacemakers? | It binds to alpha receptors here and INCREASES HR. |
What mechanism might compensate epi's increased HR? | Inc'd vagal tone. |
How does epi effect blood flow to skin, mucosa, etc? | Vasoconstriction in precapillary arterioles and sphincters results in inc'd pressure/ dec'd blood flow. |
At low doses what is the effect of epi on peripheral blood flow? | Vascular smooth muscles have A1 and B2 receptors. The threshold for B2 is lower than A1 so at low doses epi will stimulate the B2 receptors causes vasodilation and inc'd blood flow. |
Would you prescribe a non-specific beta adrenergic antagonist (beta blocker) to someone with peripheral vascular disease? | No. Blocking the B2 receptors will cause inc'd vasoconstriction and dec'd blood flow. |
What is the effect of epi on the lungs? | Bronchodilation. |
What does epi do to systolic pressure? diastolic pressure? | Inc'd contractility and CO cause higher systolic pressure, dec'd peripheral resistance d/t vasodilation of vessels going to skeletal muscles causes diastolic pressure to drop. MAP stays the same. When dose is high peripheral R will inc. |
Effect of epi of GU? | B2: Relaxes detrusor muscle, bladder fills A1: constricts sphincters. |
What are the metabolic effects of epi? | In general causes inc'd BG. Dec'd insulin, inc'd glucagon, inc'd gluconeogenesis. |
What sort of drug is atropine? What are the general effects? | Direct acting anticholinergic. Very dose dependent. Inc'd HR, dec'd near vision, dry mouth, inc'd body temp d/t dec'd sweating. |
Why would atropine have initial bradycardia at low dose? | Vagal compensation. |
What is propanolol and what are the effects? | Non-selective competitive beta antagonist. Dec'd HR and contractility mostly seen during exercise. |
What receptors are found on the eccrine glands? | Muscarinic cholinergic and adrenergic beta. Primary function is thermoregulation (why PS has a role) and found over most of body but highly on hands and feet. Nervous sweating. |
What receptors ennervate the apocrine glands? | Adrenergic receptors |