Mid-term Flashcards
SNS & PNS: central nervous system
consists of the brain and the spinal cord
SNS & PNS: peripheral nervous system
consists of neurons outside the brain and spinal cord
it is made up of two sub-systems: autonomic nervous system and the somatic nervous system
SNS & PNS: autonomic nervous system
one of two systems of the peripheral nervous system
this sub-system is made of 2 of its own sub-systems: sympathetic and parasympathetic nervous systems
this system deals with our involuntary responses
responsible for:
- control of smooth muscle i.e. bronchi, blood vessels, GI tract
- cardiac muscle which functions whether the person is conscious or not
- exocrine glands i.e. gastric, sweat, salivary
SNS & PNS: synaptic transmission
this is the process that all activity in our autonomic nervous system occurs
involves the synthesis of neurotransmitters in the nerve terminal
includes storage of the neurotransmitter in the nerve terminal awaiting an action potential
involves release if the specific neurotransmitter
after release, the neurotransmitter diffuses across the synaptic gap and reversibly binds to a receptor on the post-synaptic cell
- reversibility is an ideal mechanism when it comes to drug administration when the effects of a drug ever need to be reversed
after binding and exerting an effect, the neurotransmitter [or drug, or chemical] is released and dissociated from its binding site by a variety of mechanisms
the neurotransmitter is now degraded for use
SNS & PNS: sympathetic nervous system
or S.N.S. or adrenergic
- it is termed adrenergic for the receptors found in this system
it is responsible for our fight or flight response
sympathoMIMEtics turn on or replicate “mime” responses by stimulating receptors
- occurs through adrenergic agonist’s: alpha-beta agonist’s
sympathoLYTICs turn off or “lysis” responses by blocking receptors
- occurs through adrenergic antagonists: alpha-beta blockers
sub-type receptors: alpha-1, alpha-2, beta-1, and beta-2
drugs that are agonist or “activate” this system are similar to the effects seen with antagonist in the P.N.S.
SNS & PNS: parasympathetic nervous system
or P.N.S. or cholinergic
- it is termed cholinergic for the receptors found in this system
it is responsible for our rest and digest response
parasympathoMIMEtics turn on or replicate “mime” responses by stimulating recceptors
parasympathoLYTICs turn off or block “lysis” responses by stimulating receptors
sub-type receptors: Nicotinic N, Nicotinic M, Muscarinic
- muscarinic sub-types: M1, M2, and M3
this system is solely mediated by acetylcholine [Ach]
drugs that are antagonist or “block” this system are similar to the effects seen with agonist of the S.N.S.
SNS & PNS: stimulation of alpha-1 receptors
therapeutic effects: vasoconstriction, hemostasis [leads to blood clotting], increased peripheral resistance [leads to increased B.P.], mydriasis or pupil dilation, closure of the internal sphincter of the bladder [to keep stores of fluid]
adverse effects: hypertension [2o to widespread vasoconstriction], necrosis [2o to vasoconstriction and hemostasis], tachycardia [2o to reflex slowing of the heart]
SNS & PNS: phenylephrine
brand name: neosynephrine IV
it is a potent vasoconstrictor that exclusively stimulates alpha-1
adverse effects: vascular failure, hypotension, shock states
SNS & PNS: prazosin
a vasodilator that block alpha-1
it decreases peripheral resistance and increases vasodilation
indications: hypertension
SNS & PNS: stimulation of alpha-2 receptors
alpha-2 [unlike-1, beta-1, and beta-2] block the sympathetic response
the activation of these receptors inhibits norepinephrine
there are no therapeutic applications r/t activation of peripheral alpha-2 receptors
effects: reduces sympathetic outflow from brain to heart and blood vessels, relief of severe pain
SNS & PNS: epineprhine
it is a non-selective adrenergic agonist meaning that it will activate all alpha-beta receptors
- alpha-1, beta-1, and beta-2 will cause activation of the S.N.S.
- alpha-2 will block activation of the S.N.S
indication: cardiopulmonary arrest, ventricular fibrillation [the lethal dysrhythmia], anaphylactic shock, asthma [relived by beta-2 by causing bronchodilation]
SNS & PNS: what do alpha-1, beta-1, and beta-2 work on?
alpha-1 on blood vessels
beta-1 on the heart
beta-2 on the lungs and uterus
SNS & PNS: stimulation of beta-1 receptors
indications: cardiac arrest, heat failure, heart block [a conduction disturbance]
therapeutic effects: tachycardia, increase in myocardial contractility, increase in lipolysis [burning of fat for energy]
- an antagonist to beta-1 would cause the opposite effects which would be beneficial for pt.’s with hypertension
SNS & PNS: stimulation of beta-2 receptors
therapeutic applications limited to the lungs and uterus
indications: asthma, hypertension, delay pre-term labor
therapeutic effects: bronchodilation, vasodilation, slightly decreased peripheral resistance, increased muscle and liver glycolysis [monitor pt. for hyperglycemia], increased release of glucgon [breaks down to become glucose in the blood], relaxation of uterine smooth muscle
adverse effects: hyperglycemia, tremors [2o to activation of S.N.S]
SNS & PNS: isoproterenol
it is a non-selective beta-2 stimulant
- its non-selectiveness signifies that it can stimulate beta-1 as well, causing unwanted cardiac stimulation
indication: CHF, various types of shock, hypoperfusion, asthma, bronchitis, emphysema
adverse effects: primarily r/t cardiac stimulation
SNS & PNS: propranolol
it is a non-specific beta blocker therefore it block both beta-1 and beta-2 receptors
indication: cardiovascular disorders
adverse effects: r/t cardiac and respiratory effects
- discontinue administration of this drug slowly to prevent rebound tachycardia leading to angina and possibly myocardial infarction
SNS & PNS: what do muscarinic M1, M2, and M3 work on?
M1 works on the brain
M2 works on the heart
M3 works on every other organ
SNS & PNS: stimulation of P.N.S. effectss
SLUGBAM salivation, secretions, sweat lacrimation [eye moisture] urination GI upset [diarrhea] bradycardia, bowel movement, bronchoconstriction abdominal cramps, anorexia miosis [pupillary constriction]
SNS & PNS: pilocarpine
binds solely to cholinergic receptors
indications: simple and acute glaucoma [for its miotic effects], preoperative and postoperative elevated intraocular pressure, drug induced mydriasis [pupil dilation]
SNS & PNS: neostigmine
brand name: prostigmin
indications: myasthenia gravis [a neuromuscular disorder] to minimize muscle fatigue
adverse effects: cholinergic crisis [an excess of Ach]
it has a cholinergic effect despite it not binding to a cholinergic receptor
- the drug inhibits the enzyme cholinesterase which breaks down Ach, if that action is inhibited there is more Ach which causes the cholinergic agonist effect
SNS & PNS: atropine
an anti-cholinergic drug, which acts as an antidote to a cholinergic crisis
indication: preoperative drying of secretions [facilitates intubation, if needed], acute cardiac emergencies, ophthalmic disorders, motion sickness, diarrhea [by slowing down gastric peristalsis
SNS & PNS: excessive blockage of P.N.S. effects
increased intraocular pressure mydriasis [dilation of pupils] photophobia decreased sweating dry mouth decreased bronchial secretions respiratory depression decreased GI motility w/ possible constipation decreased B.P. followed by increase B.P. - these drugs will decrease B.P. causing the heart to compensate for the decrease by increasing the heart rate which causes the rise in B.P. tachycardia and, possibly, palpitations urinary retention vasodilation drowsiness, confusion, and agitation
SNS & PNS: anti-cholinergic poisoning
a lack of Ach remember: mad as a hatter blind as a bat red ass a beet dry as a bone
diuretics: thiazides
the largest group of diuretics, structurally r/t the antibacterial sulfoamides [ask pt. for allergies to sulfa]
prototype: hydrochlorothiazide [HCTZ]
acts in the early tubules
- excretes Na and Cl by inhibiting the ion pumps that work in Na and Cl reabsorption
- furthermore, it increases excretion of water-soluble vit.’s, K, HCO3, and Mg and decreases the excretion of Ca
indications: hypertension, edema [resulting from CHF, hepatic cirrhosis, renal disease, long-term steroid or estrogen therapy]
nursing interventions: ID allergies to sulfa, determine renal and hepatic status, ID blood glucose and uric acid levels
decreases GFR and increases BUN, blood glucose, and uric acid
diuretics: loop diuretics
or high-ceiling diuretics, is rapid-acting which takes effect in less than 10 minutes when administered IV
prototype: furosemide [lasix]
acts in the loop of Henle
- inhibits the reabsorption of Na, Cl, and water
- furthermore, it excretes K, Mg, and Ca [thiazides increases the levels of Ca]
indications: reduces peripheral edema [from pulmonary edema, CHF, hepatic or renal disease], hypertension, pre-existing renal disease [loop preferred b/c it has no effect on the GFR, unlike thiazides
adverse effects: F&E imbalance [may cause hypovoleia and dehydration], ototoxicity [occurs w/ rapid IV administration]
can increase blood glucose, low-density lipoprotein, total cholesterol, uric acid and triglyceride levels
diuretics: [aldosterone-antagonist] potassium sparing diuretics
acts in the late distal tubules
blocks the effect of aldosterone causing the body to excrete Na yet hold on to K
prototype: spironolactone [aldactone]
indications: hyperaldosteronism, minimizes K loss
adverse effects: impotence, menstrual irregularities, gynecomastia, interacts w/ salicylates, hyperkalemia
interferes w/ testosterone synthesis, which leads to altered estrogenic and androgenic activity; a major use is in diagnosisng and treating primary hyperaldosteronism
