Autonomic Nervous System Flashcards
What is the main function of the sympathetic nervous system?
Prepares body for stress (fight or flight)
What is the main function of the parasympathetic nervous system?
Promotes relaxation and recovery (rest and digest)
What is the primary neurotransmitter for the SNS?
Norepinephrine (postganglionic)
Acetylcholine (preganglionic)
What is the primary neurotransmitter for the PNS?
Acetylcholine (both pre-and postganglionic)
What does the SNS do to HR?
Increases
What does the PNS do to HR?
Decreases
What does the SNS do to respiratory rate?
Increases
What does the PNS do to respiratory rate?
Decreases
What does the SNS do to digestive system?
Inhibits digestion
What does the PNS do to digestive system?
Stimulates digestion
What does the SNS do to pupillary response?
Dilation
What does the PNS do to pupillary response?
Constriction
How does the SNS effect sweating?
Stimulated (sweat glands)
How does the PNS effect sweating?
Inhibited
How does the SNS effect bladder function?
Inhibits contraction
How does the PNS effect bladder function?
Stimulates contraction
How does the SNS effect sexual function?
Stimulates ejaculation and orgasm
How does the PNS effect sexual function?
Stimulates erection
How does the autonomic nervous system respond to high blood pressure?
High blood pressure - > decreased sympathetic output (vasodilation, decreased HR) + increased parasympathetic output (slower HR)
How does the autonomic nervous system respond to low blood pressure?
Low blood pressure - > increased sympathetic output (vasoconstriction, increased HR) + decreased parasympathetic output (increased HR)
Receptor activation response of Sympathomimetic Alpha-1 (a1) Agonist Receptors:
Activation results in vasoconstriction, increasing blood pressure
Pupillary dilation (mydriasis)
Bladder sphincter contraction, promoting retention of urine
Receptor activation response of sympathomimetic Alpha - 2 (a2) agonist Receptors:
Inhibition of further norepinephrine release
Inhibition of acetylcholine release
Inhibition of insulin release
Decreases secretion of aqueous humor
Platelet aggregation
Receptor activation response of sympathomimetic Beta - 1 (B1) Receptors:
Tachycardia (stimulation)
Increased myocardial contractibility
Increased release of renin
Receptor activation response of sympathomimetic Beta - 2 (B2) Receptors:
Slight decrease in peripheral resistance
Bronchodilation
Increased muscle and liver glycogenolysis
Increased release of glucagon
Relaxed uterine muscles
What is the mechanism of action of sympathomimetic agents?
They mimic the effects of norepinephrine and epinephrine by activating adrenergic receptors. They can act on alpha and beta receptors, either selectively or non-selectively.
Receptor activation response of sympatholytic Alpha-1 antagonists (blockers):
Relax smooth muscle
Decrease vascular resistance
Receptor activation response of sympatholytic Alpha-2 antagonists (blockers):
Used mainly in research
Depression
Receptor activation response of Beta -1 Adrenergic antagonist (blocker)?
Reduce HR and cardiac output
Reduce renin secretion
Reduce intraocular pressure
Receptor activation response of Beta -2 Adrenergic antagonist (blocker)?
Smooth muscle constriction (bronchial, vascular)
Reduce hepatic glucose
Mask Hypoglycemia
What is the mechanism of action of adrenergic antagonists?
Bind to adrenergic receptors and inhibit the effects of norepinephrine and epinephrine
Mechanism of action of alpha blockers?
Block alpha - 1 receptors
Mechanism of action of beta blockers?
Block beta -1 & 2 receptors (propranolol for non-selective, metoprolol for beta-1 selective)
Receptor activation response of acetylcholine Muscarinic Receptors antagonists:
Relax smooth muscle
Decrease gland secretions
Increase HR
Receptor activation response of acetylcholine Nicotinic Receptors antagonists:
Neuromuscular blocking agents
Mechanism of action of muscarinic and nicotinic receptors
These drugs mimic the action of acetylcholine by activating muscarinic and nicotinic receptors, promoting parasympathetic nervous system activity
Therapeutic Use of sympathomimetic alpha 1 agonists?
Elevate BP
Nasal decongestion
Adjunct to local anesthesia
Promote Hemostatis
Treat urinary stress or urge incontinence
Mydriasis
Adverse effects of sympathomimetic A1 Activation?
Hypertension (most common with IV)
Necrosis (from IV or if injection in finger, hands, feet)
Bradycardia (baroreceptor reflex)
Therapeutic use of sympathomimetic A2 Agonists?
Peripheral:
^ BP
Nasal decongestion
Promote hemostatis (platelet aggregation)
Decrease aqueous humor production (glaucoma tx)
Central:
Lower BP
Adjunct to local anesthesia
Relieve of severe pain
Adverse effects of a2 sympathomimetic agonist activation?
HTN (IV)
Necrosis (IV)
Bradycardia
What is the primary response of the Adrenergic agonist drug Albuterol, and what adrenoreceptor does is act on?
Asthma, B2
What is the primary response of the Adrenergic agonist drug Clonidine, and what adrenoreceptor does is act on?
HTN, a2
What is the primary response of the Adrenergic agonist drug Dobutamine, and what adrenoreceptor does is act on?
Cardiac stimulant, B1, B2
What is the primary response of the Adrenergic agonist drug Levophed, and what adrenoreceptor does is act on?
Shock, a1, B1
What is the primary response of the Adrenergic agonist drug Afrin, and what adrenoreceptor does is act on?
Nasal congestion, a1 & partial a2
What is the primary response of the Adrenergic agonist drug Phylephrine, and what adrenoreceptor does is act on?
Nasal congestion, a1
What is the primary response of the Adrenergic agonist drug Terbutaline, and what adrenoreceptor does is act on?
Slow uterine contractions, B2
What is the primary response of the Adrenergic agonist drug Epinephrine, and what adrenoreceptor does is act on?
Anaphalyactic Shock, cardiac arrest.
A1, B1, B2
What is the primary use of Alpha-Adrenergic antagonist (blocker) Terazosin?
HTN
BPH
A1
What is the primary use of Alpha-Adrenergic antagonist (blocker) Prazosin?
HTN
BPH
A1
What is the primary use of Alpha-Adrenergic antagonist (blocker) Tamsulosin?
BPH
A1
What is the primary use of Alpha-Adrenergic antagonist (blocker) Phenoxybenzamine?
HTN emergencies
a1, 2
What is the primary use of Alpha-Adrenergic antagonist (blocker) Mirtazapine?
Depression
A2
What is the primary use of beta-Adrenergic antagonist (blocker) Propanalol?
HTN
Angina
B1,2
What is the primary use of beta-Adrenergic antagonist (blocker) Metoprolol?
HTN
B1
What is the primary use of beta-Adrenergic antagonist (blocker) Acebutolol?
HTN
Cardiac Arrythmias
B1
What is the primary use of beta-Adrenergic antagonist (blocker) Atenolol?
HTN
Angina
Acute MI
B1
What is the primary use of beta-Adrenergic antagonist (blocker) Labetalol?
HTN
A1, B1,2
What is the primary use of beta-Adrenergic antagonist (blocker) Carvedilol?
HTN
HF
A1, B1,2
What is the primary use of beta-Adrenergic antagonist (blocker) Timolol?
HTN
Acute MI
Glaucoma
Migraine
B1, 2
Therapeutic use of direct-acting acetylcholine agonist acetylcholine?
Little therapeutic use due to rapid breakdown
Therapeutic use of direct-acting acetylcholine agonist Carbachol?
Produces miosis; glaucoma treatment
Therapeutic use of direct-acting acetylcholine agonist Bethanechol?
Urologic; stimulates atonic bladder
Therapeutic use of direct-acting acetylcholine agonist Pilocarpine?
Produces rapid miosis; glaucoma treatment; produces salivation; siogren’s syndrom
Therapeutic use of direct-acting acetylcholine agonist cevimeline?
Dry mouth;
post radiation treatment
Siogren’s syndrome
Therapeutic use of direct-acting acetylcholine agonist verenicline?
Smoking cessation
Therapeutic use of indirect-acting acetylcholine agonist physostigmine?
Increase intestinal/bladder motility
Treat drug OD with anticholinergic agents
Glaucoma
Therapeutic use of indirect-acting acetylcholine agonist Neostigmine?
Myasthenia gravis symptoms
Therapeutic use of indirect-acting acetylcholine agonist Pyridostigmine?
Chronic treatment myasthenia gravis
Therapeutic use of indirect-acting acetylcholine agonist Tacrine, Donepezil, ravastigmine, and galatamine?
Delay dementia progression of Alzheimer’s Disease and Parkinson’s Disease
