Autonomic Nervous System (ANS) Function
Controls involuntary body functions (e.g., heart rate, digestion, respiration)
Afferent Fibers
Sensory input in the Autonomic Nervous System.
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Flashcards covering the key concepts of the autonomic nervous system and related drugs.
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Autonomic Nervous System (ANS) Function
Controls involuntary body functions (e.g., heart rate, digestion, respiration)
Afferent Fibers
Sensory input in the Autonomic Nervous System.
Central Integration
Processes information in the Autonomic Nervous System.
Efferent Fibers
Preganglionic and postganglionic motor fibers in the Autonomic Nervous System.
Parasympathetic Nervous System (PANS)
"Rest and digest," conserves energy, increases digestion.
Sympathetic Nervous System (SANS)
"Fight or flight," increases heart rate, dilates pupils.
Effect comparison (PANS vs. SANS)
Opposing effects on the same organs.
PANS Neurotransmitter
Acetylcholine (ACh) at both ganglion and effector in the Parasympathetic Nervous System
SANS Neurotransmitters
ACh at ganglion, Norepinephrine (NE) at effector in the Sympathetic Nervous System
Cholinergic receptors
Nicotinic (at ganglia) and Muscarinic (at effector)
Adrenergic receptors
Alpha (α) and Beta (β)
Direct-acting agents (Cholinergic)
Bind directly to receptors (e.g., Pilocarpine).
Indirect-acting agents (Cholinergic)
Inhibit cholinesterase, increasing ACh (e.g., Neostigmine).
Pharmacologic effects of Cholinergic Agents
Decrease heart rate, vasodilation, lower blood pressure.
Pharmacologic effects of Cholinergic Agents
Increase GI motility and secretions.
Miosis
Pupil constriction
Cycloplegia
Paralysis of ciliary muscle
Uses of Cholinergic Agents
Treats Glaucoma, xerostomia, urinary retention (non-obstructive)
Mechanism of Anticholinergic Agents
Block muscarinic receptors, inhibiting ACh effects in PANS.
Pharmacologic effects of Anticholinergic Agents
Decrease saliva and bronchial secretions
Mydriasis
Pupil dilation
Pharmacologic effects of Anticholinergic Agents
Decrease GI motility and secretions
Uses of Anticholinergic Agents
Pre-op to reduce secretions, ophthalmic exams (mydriasis + cycloplegia)
Uses of Anticholinergic Agents
Treats veractive bladder, motion sickness (e.g., scopolamine patch)
Contraindications of Anticholinergic Agents
Angle-closure glaucoma, prostatic hypertrophy, GI/GU obstruction
Adverse effects of Anticholinergic Agents
Dry mouth, blurred vision, constipation, urinary retention
Alpha-blockers (α-blockers)
Block vasoconstriction, lowers BP, may cause reflex tachycardia
Beta-blockers (β-blockers)
Block β-receptors, lowers heart rate and contractility, can cause bronchoconstriction
Combined blockers (α/β)
Example: Labetalol - lowers BP without reflex tachycardia
Non-depolarizing (competitive) Neuromuscular Blocking Drugs
Block ACh causing muscle paralysis
Depolarizing Neuromuscular Blocking Drugs
Constantly stimulate leading to eventual paralysis
Uses of Neuromuscular Blocking Drugs
Muscle relaxation during surgery
Caution: Succinylcholine
Risk of malignant hyperthermia
Epinephrine reversal
Giving α-blocker before epinephrine can drop BP instead of raising it.
Pseudoephedrine regulation
Restricted due to its use in methamphetamine production.