Pharm: ANS Pharmacology Flashcards
Functional integration in the ANS is provided mainly through ____ feedback.
negative
The ANS uses modulatory pre- and post-synaptic receptors at the ____ level and ____ ____ at the system level.
local; homeostatic reflexes
Local feedback control has been found at the level of _____ in all systems investigated.
the nerve endings
Describe the feedback loop for norepinephrine and its receptor modulation.
there is a negative feedback loop for NE upon its own release, modulated via the alpha-2 receptors located on the presynaptic nerve membrane
What is an autoreceptor?
a receptor that binds the primary substance and thereby regulate its release
Nicotinic transmission is primary in what type of synapse?
ganglionic synapse
How do post-synaptic receptors modulate signaling?
by evoking slow excitatory or inhibitory postsynaptic potentials (EPSPs or IPSPs)
Blood pressure is regulated by a neural response and a hormonal response. Name both.
neural = baroreceptor reflex hormonal = renin-angiotensin-aldosterone system
Any deviation in the blood pressure ____ ____ causes a change in ANS activity and R-A-A levels.
“set point” (the MAP level determined by the vasomotor center and renal sensors
A decrease in BP caused by hemorrhage causes increased ____ discharge and ____ release.
SANS; renin
Sympathetic nerves will release what neurotransmitter?
norepinephrine
____-blocking drugs can block the effects of the SANS response to hemorrhage, including the increased peripheral vascular resistance, venous tone, heart rate, and cardiac force.
ganglion-blocking
Under the influence of increased aldosterone levels, what happens to replenish the blood volume?
retention of salt and water in the kidney
True or false: a vasodilator given alone will work to decrease hypotension over the long-term.
False - if the vessels are chronically dilated to decrease hypotension there will be compensatory mechanisms, including retention of salt and water in the kidneys and tachycardia; these may be overcome by the use of additional drugs
Where are the main autonomic nervous receptors located in the body? (thing organ systems)
heart, GI tract, GU tract, skin, neuro, pulm
Nicotinic receptors are located where? Name the 2 types.
- located in the sympathetic ganglia = nicotinic N (Nn) receptors
- located in PSNS/muscles = nicotinic muscle (Nm) aka muscarinic (M) receptors
What effects does the SNS have on the heart?
increase contractility/HR, increase SA/pacemaker
Through what receptors in cardiac muscle cells does the SNS function?
Beta-1 and beta-2
SNS effect through alpha receptors has what effect on the vasculature?
constrict skin, splanchnic
SNS effect through beta-2 receptors has what effect on the vasculature?
relax vessels supplying skeletal muscle
SNS effect through alpha-2 and beta-2 receptors has what effect on the GI tract?
relax the wall; alpha 2 will also decrease secretions
SNS effect through alpha-1 receptors has what effect on the GI tract?
sphincter contraction
SNS effect through beta-2 receptors has what effect on the bronchial smooth muscle?
relax bronchial smooth muscle
SNS effect through alpha-1 receptors has what effect on the GU tract?
sphincter contraction
SNS effect through alpha receptors has what effect on the GU tract of males, specifically?
ejaculation
SNS effect through beta-2 receptors has what effect on the GU tract?
detrussor muscle relaxation
SNS effect through alpha receptors has what effect on the skin?
apocrine (stress) sweat
SNS effect through alpha receptors has what effect on the metabolism?
increase glycogenolysis and gluconeogenesis
SNS effect has what effect on the metabolism?
- via alpha receptors = increase glycogenolysis and gluconeogenesis
- via beta receptors = Beta-1 increase gluconeogenesis; Beta-1/2 increase glycogenolysis
- glycogen-ALL-isis = all receptors do glycogenolysis
- gluco-THREE-ogenesis = three receptors do gluconeogenesis (alpha 1, alpha 2, beta 1)
SNS effect through beta-1 receptors has what effect on the metabolism?
increase renin release
PNS effect through M receptors has what effect on the skin?
thermoregulatory sweat
PNS effect through M receptors has what effect on the GU tract (of the male, specifically)?
erection
PNS effect through M2 receptors has what effect on the GU tract?
detrussor contraction, sphincter relaxation
PNS effect through M3 receptors has what effect on the bronchial smooth muscle?
contraction
PNS effect through M3 receptors has what effect on the GI tract?
wall contraction, sphincter relaxation, increase secretion
PNS effect through M receptors has what effect on the vasculature in cats/dogs but NOT humans?
arterial relaxation in skeletal muscle
PNS effect through M2 receptors has what effect on the heart?
SA node decelerates, decrease atria contractility
Phenylephrine:
which receptor type?
agonist versus antagonist?
alpha-agonist
non-selective
Phentolamine:
which receptor type?
agonist versus antagonist?
alpha-antagonist
1&2
Prazosin:
which receptor type?
agonist versus antagonist?
alpha-1-antagonist
Isoproterenol:
which receptor type?
agonist versus antagonist?
beta-agonist
1&2
Dobutamine:
which receptor type?
agonist versus antagonist?
beta-1-agonist
Albuterol:
which receptor type?
agonist versus antagonist?
beta-2-agonist
Atenolol:
which receptor type?
agonist versus antagonist?
beta-1-antagonist
Propanolol:
which receptor type?
agonist versus antagonist?
beta-antagonist
1&2
Norepinephrine:
which receptor type?
agonist versus antagonist?
alpha-1&2 and beta-1 agonist
Epinephrine:
which receptor type?
agonist versus antagonist?
alpha-1&2, beta-1&2 agonist
Baroreceptors provide feedback on _______ to the _______.
mean arterial pressure; vasomotor center
What effect does the sympathetic ANS have on peripheral vascular resistance and venous tone?
increases it
What effect does the sympathetic ANS have on contractile force and heart rate?
increases it
What effect does the parasympathetic ANS have on contractile force and venous tone?
none (according to Sweatman’s diagram)
What effect does the parasympathetic ANS have on heart rate?
decreases it
Phenylephrine is often given to treat what? It can also cause what unintended effects?
given for: hypotension, nasal congestion (it’s a vasoconstrictor, stimulating SNS)
can also cause: elevated BP (via reflex bradycardia–baroreceptors sense increased BP, they slow the heart) and urinary retention (SNS stimulation is relaxing the detrussor m, must contract in order to urinate)
Phenylephrine is associated with or can cause what unintended effects?
elevated BP, reflex bradycardia, urinary retention
What receptor types predominate in the heart, and which in the lungs?
Beta-1 in the heart; beta-2 in the lungs
*1 heart, 2 lungs
What autonomic receptor is in the vasculature and what does stimulation of it do?
alpha-1: constricts skin/splanchnic vessels
beta-2: dilates skeletal muscle vessels
Beta-1 receptor agonists cause a stimulation of what?
heart rate and force; function to increase cardiac activity which elevates the BP
What type of receptors in cats/dogs cause what type of effect in arterial systems and skeletal muscle?
muscarinic receptors; relaxatory
Muscarinic activity in the vasculature tends to be on a local or systemic level?
local
SNS tends to cause ____ of digestive activity.
a decrease; “flight, fright, fight”
PSNS tends to cause ____ of digestive activity.
increase; “rest and digest”
Bronchial smooth muscle constriction is mediated by what ANS/nerve?
PSNS = vagally-mediated bronchoconstriction (wheezing)
What type of drugs would cause broncho-relaxation?
Cholinergic antagonists, or beta-2 adrenergic agonist (different mechanisms)
What would happen if a patient took too much beta-2 adrenergic agonist for bronchodilation? (in terms of off-target effects)
it would stimulate the heart
For a drug that acts directly on the heart to increase pumping, what other effect would be seen due to the presence and function of baroreceptors?
faster HR = higher bp, so baroreceptors would induce vasodilation to correct
For a patient with hypotension, what kinds of drugs could you give to increase bp?
- cardiac stimulator
- vasoconstrictor
- fluid retention
How does using a vasoconstrictor such as phenylephrine help with nasal congestion?
nasal congestion is occurring because the blood vessels in the nasal passages are dilated; so constrict them and congestion decreases
Phentolamine/Prazosin are both alpha antagonists. What are they used to treat?
- dermal necrosis (due to lack of blood supply to digits)
- hypertension
- BPH (benign prostatic hypertrophy)
- Raynaud’s syndrome
What are some typical adverse effects expected with the use of Phentolamine/Prazosin?
tachycardia, weakness, dizziness, flushing (Vaso-vagal reaction) orthostatic hypotension, nasal congestion
Isoproterenol 1+2 and dobutamine 1 are both beta agonists. What are they used to treat?
bradycardia, cardiac arrest, AV block
What are some typical adverse effects expected with the use of Isoproterenol 1+2 and dobutamine 1?
serious reactions: ventricular arrhythmia, tachyarrhythmia, HTN, pulmonary edema
common reactions: tachycardia, angina, dizziness/flushing, orthostatic hypotension, nasal congestion
Atenolol 1 and Propranolol 1+2 are both beta antagonists. What are they used to treat?
- angina
- hypertension
What are some typical adverse effects expected with the use of Atenolol 1 and Propranolol 1+2?
Serious: CHF, ventricular arrhythmia, severe bradycardia, MI (if abrupt discontinuation), Raynaud’s, bronchospasm
Common: bradycardia, orthostatic hypotension, dyspnea, bronchospasm ,cold extremities (blood shunting)
What types of AEs would Epi and NE produce?
Severe: HTN, bradycardia, asthma exacerbation, extravasational necrosis, bronchospasm, cold extremities, dyspnea
What drugs have an effect on the PSNS muscarinic receptors?
Agonists: Bethanechol
Antagonist: Atropine
Is atropine useful for treating asthma?
Yes because it is a cholinergic Muscarinic antagonist (can also use a beta-2 agonist)
What is mydriasis and miosis?
mydriasis is pupillary dilation; miosis is pupillary constriction
What are the side effects of atropine?
Severe: bronchospasm, hypotension, tachycardia
Other: urinary urgency, vasomotor response, diarrhea, diaphoresis
What is atropine used to treat?
bradycardia, aspiration prophylaxis, block cardio-vagal response
Is PSNS or SNS the dominant tone in the eye?
PSNS
Most pharmacology of the eye involves what route of drug delivery?
topical application
In the eye:
Iris radial muscle is contracted via ____.
Iris circular muscle is contracted via ____.
Ciliary muscle is contracted via ____.
alpha-1
M3
M3
How would you induce mydriasis in the eye?
sympathetic agonist or parasympathetic antagonist
How would you induce miosis in the eye?
sympathetic antagonist or parasympathetic agonist
Stimulation of ____ receptors is involved in the secretion of aqueous humor, too much of which can cause glaucoma. Therefore, to treat glaucoma, ____ (type of drugs) are used.
Beta-2; beta-blockers
