Autonomic pharmacology (physiology) Flashcards
What is another name for adrenergic agonists?
Sympathomimetics
What is another name for adrenergic antagonists?
Sympatholytics
What is another name for cholinergic agonists?
Parasympathomimetics
What is another name for cholinergic antagonists?
Parasympatholytics
What are some uses of autonomic drugs?
13
(1) Hypertension
(2) Hypotension
(3) Angina
(4) Cardiac arrhythmias
(5) Attention deficit hyperkinetic disorder
(6) Asthma
(7) Glaucoma/other eye diseases
(8) Allergies
(9) Urinary retention (bladder atony)
(10) Incontinence
(11) Hyperthyroidism
(12) Immunological diseases
(13) Benign prostatic hyperplasia
What is the purpose of the autonomic nervous system?
To maintain internal homeostasis
How is the autonomic nervous system divided?
Efferent: sympathetic and parasympathetic
Afferent: receptors
Which half of the ANS is dominant at rest?
Parasympathetic
Which division of the ANS innervates organ systems discretely? All at once?
Sympathetic - all at once
Parasyhmpathetic - discretely (ex. when your pupils constrict, you don’t urinate too)
Where does epinephrine in the periphery originate?
Adrenals
Where does epinephrine in the CNS originate?
CNS
What is the functional arrangement of the sympathetic nervous system?
(5)
(1) Preganglionic cholinergic fiber synapses on (2) nicotinic receptor of postganglionic neuron, which sends a (3) noradrenergic fiber to (4) α1, β1, β2 receptors on an effector cell. (5) There is also an α2 receptor on the postganglionic neuron
What is the functional arrangement of the parasympathetic nervous system?
(4)
(1) Preganglionic cholinergic fiber synapses on (2) nicotinic receptor of postganglionic neuron, which sends a (3) cholinergic fiber to (4) muscarinic receptors on an effector cell
Why should drugs that act on nicotinic receptors be avoided?
They affect both sympathetic and parasympathetic ganglia
What is the α2 receptor?
A pre-junctional autoregulatory receptor that turns off continued release of epinephrine when activated
Eye physiology:
What are mydriasis and miosis?
Mydriasis: pupil dilation
Miosis: pupil constriction
Eye physiology:
What receptors are found on the dilator muscle?
α1 (sympathetic effector)
What receptors are found on the ciliary muscles?
Muscarinic (parasympathetic effector)
Eye physiology:
What happens when radial ciliary muscles relax? When they contract?
Relaxation: tension on lens leads to distant vision
Contraction: lens accomodates for near vision
Eye physiology:
Eye physiology:
What happens when longitudinal ciliary muscles contract?
Aqueous humor of the eye drains through the Canal of Schlemm
Eye physiology:
What receptors are found on the constrictor muscle?
Muscarinic (parasympathetic effector)
Eye physiology:
How can mydriasis be induced?
α1 agonist or muscarinic antagonist in eyedrops
Eye physiology:
What happens when glaucoma patients are given muscarinic agonists?
(3)
(1) Longitudinal ciliary muscle contracts, draining aqueous humor via Canal of Schlemm
(2) Radial ciliary muscles contract and cause near vision, and
(3) Constrictor muscles contract, leading to constricted pupils and poor night vision
What controls systolic blood pressure?
(1) Cardiac output, which is determined by (2) heart rate and (3) force of contraction
Which sympathetic receptor is most prevalent in the heart and what does it cause?
(2)
(1) β1
(2) Increase in rate and force of contraction
What does parasympathetic innervation to the heart cause?
Decrease in rate and force of contraction
What sympathetic receptors are present in blood vessels and what do they cause?
(2)
(1) α1 - constriction of vascular smooth muscle
(2) β2 - relaxation of vascular smooth muscle
What type of drugs can be given to someone with a low blood pressure?
(2)
(1) β1 agonist
(2) Muscarinic antagonist
What type of drug can be given to someone with a high blood pressure? What shouldn’t be given?
β1 antagonist
No muscarinic agonist due to side effects
What controls diastolic blood pressure?
Dilation/constriction of blood vessels and stroke volume (decrease in stroke volume lowers diastolic BP)
What happens when both α1 and β2 receptors in blood vessels are activated?
α1 dominates, leading to constriction of vascular smooth muscle
Where is parasympathetic innervation in blood vessels?
No parasympathetic innervation to vascular smooth muscle
Vascular endothelium has muscarinic receptors which can be activated by drugs, leading to vasodilation
What sympathetic receptors are found in the lungs and what do they cause?
(2)
(1) β2
(2) relaxation of bronchial smooth muscle
What does parasympathetic innervation to the lungs cause?
Constriction of bronchial smooth muscle
How is asthma treated?
β2 agonists, muscarinic antagonists
What sympathetic receptors are found in the GI smooth muscle and what do they cause?
(2)
(1) β2
(2) Relaxation of GI smooth muscle
What does parasympathetic innervation to the GI smooth muscle cause?
Contraction of GI smooth muscle
What sympathetic receptors are found in the GI sphincters and what do they cause?
(2)
(1) α1
(2) Contraction of GI sphincters
What does parasympathetic innervation to the GI sphincters cause?
Relaxation of GI spincters
What functions of the GI tract do the SNS inhibit and PNS promote?
(3)
(1) Urination
(2) Digestion
(3) Defecation
What sympathetic receptors are found on the detrusor muscle of the bladder and what do they cause?
(2)
(1) β2
(2) Relaxation of the detrusor muscle
What does parasympathetic innervation to the detrusor muscle of the bladder cause?
Contraction of the detrusor muscle
What sympathetic receptors are found in the internal/urethral sphincter of the bladder and what do they cause?
(2)
(1) α1
(2) Contraction of the internal/urethral sphincter
What does parasympathetic innervation to the internal/urethral sphincter of the bladder cause?
Relaxation of the internal/urethral sphincter
Why does urination occur more frequently when one is anxious (sympathetic activation) if it leads to contraction of the internal sphincter of the bladder?
Sympathetic activation leads to increased heart rate, cardiac output, and thus glomerular filtration rate, leading to increased urine production
What sympathetic receptors are found in the uterus and what do they cause?
(2)
(1) α1 - increase contractions
(2) β2 - decrease contractions
Would you give α1 agonists to pregnant women in labor? Why or why not?
No because they result in sustained rather than intermittent contraction
What sympathetic receptors are found in the salivary glands and what do they cause?
(2)
(1) α1 and β2
2) Increase viscous secretions (not seen much
What does parasympathetic innervation to the salivary glands cause?
Increased watery secretions
Where is monoamine oxidase (MAO) found and what does it do?
2
(1) Sympathetic neuronal varicosity and effector cell
(2) Removes norepinephrine
How is norepinephrine eliminated from the synapse?
90% is eliminated by reuptake into the sympathetic neuronal varicosity, the rest is taken up by the effector cell
