Introduction to Autonomic Pharmacology Quiz Flashcards
Which of the following receptors will cause mydriasis when activated? α1 α2 β1 β2 β3 D1 D2 M2 M3 Nm Nn
α1
Which of the following receptors will cause increased gluconeogenesis when activated? β1 β2 β3 D1 D2 M2 M3 Nm Nn
β2
Which of the following receptors will cause selected dilation of renal vessels when activated? α1 α2 β1 β2 β3 D1 D2 M2 M3 Nm Nn
D1
Which of the following receptors will cause constriction of bladder internal sphincter when activated? α1 α2 β1 β2 β3 D1 D2 M2 M3 Nm Nn
α1
Which of the following receptors will cause decreased AV conduction when activated? α1 α1 β1 β2 β3 D1 D2 M2 M3 Nm Nn
M2
Which of the following receptors will cause mydriasis when blocked? α1 α2 β1 β2 β3 D1 D2 M3 Nm
M3
Which of the following receptors will cause decreased aqueous humor outflow when blocked? α1 α2 β1 β2 β3 D1 D2 M2 M3 Nm
M3
Which of the following receptors will cause tachycardia when blocked?
(more than one correct answer, think about direct and indirect mechanisms) α1 α2 β1 β2 β3 D1 D2 M2 M3 Nm Nn
α1, M2, Nn
Activation of M2 receptors leads to decreased heart rate. Blockage of M2 will result in tachycardia.
Blockade of α1 will result in decreased blood pressure, the baroreceptor reflex will cause tachycardia to maintain mean arterial pressure.
The predominant tone of the heart is determined by the parasympathetic nervous system. Blockade of Nn receptors in the autonomic ganglia will result in decreased parasympathetic output and result in tachycardia.
Which of the following receptors will cause relaxation of the bladder external sphincter when blocked? α1 α2 β1 β2 β3 D1 D2 M2 M3 Nm
Nm
The external bladder sphincter is under voluntary control. Therefore contraction is controlled by the somatic nervous system and Nm receptors.
What would the answer be if the question asked about the internal sphincter of the bladder?
Which of the following receptors will cause decreased intestinal peristalsis when blocked? α1 α2 β1 β2 β3 D1 D2 M3 Nm
M3
Which of the following fibers of the peripheral nervous system are short and unmyelinated? Postganglionic parasympathetic Postganglionic sympathetic Preganglionic parasympathetic Preganglionic sympathetic A-alpha motor A-beta sensory
Postganglionic parasympathetic
Postganglionic fibers of the ANS are all unmyelinated. Those of the parasympathetic nervous system are short.
B) Postganglionic sympathetic fibers are usually long.
C, D, E, F) All these fibers are myelinated.
Fibers of the sympathetic nervous system that utilize acetylcholine as the postganglionic neurotransmitter innervate which of the following tissues/organs? Ciliary muscle Skeletal muscle Sweat glands Adrenal medulla Gastrointestinal sphincters Salivary glands
Sweat glands
The vast majority of sweat glands in the body are innervated by sympathetic cholinergic neurons, i.e. sympathetic postganglionic neurons that happen to release acetylcholine instead of norepinephrine.
Which of the following is the predominant mechanism that terminates the action of the main neurotransmitter released by postganglionic adrenergic nerve endings?
Metabolism by catechol-O-methyl-transferase
Metabolism by monoamine oxidase
Diffusion away from the synaptic cleft
Metabolism by acetylcholinesterase
Reuptake into the nerve ending
Uptake by effector cells
Reuptake into the nerve ending
The termination of action of norepinephrine released from the adrenergic nerve ending, mainly occurs by reuptake of the neurotransmitter into the adrenergic terminal by the norepinephrine transporter (NET).
Which of the following is a site where autonomic receptors are primarily Nn cholinergic? Celiac ganglion Urinary bladder Sinoatrial node Vascular smooth muscle Lower esophageal sphincter
Celiac ganglion
In all autonomic ganglia receptors are primarily Nn.
Which of the following effects is most likely mediated by the activation of peripheral postsynaptic β1 receptors?
Coronary vasoconstriction Increased synthesis of angiotensin II Increased intestinal peristalsis Increased gluconeogenesis Decreased blood pressure
Increased synthesis of angiotensin II
Activation of β1 receptors increases renin secretion. Renin is the enzyme that catalyzes the biosynthesis of angiotensin II.
Which of the following is the predominant mechanism that terminates the action of the main neurotransmitter released by preganglionic nerve endings?
Metabolism by choline acetyltransferase Metabolism by monoamine oxidase Diffusion away from the synaptic cleft Metabolism by acetylcholinesterase Reuptake into the nerve ending Uptake by effector cells
Metabolism by acetylcholinesterase
The main neurotransmitter released by preganglionic nerve endings (both sympathetic and parasympathetic) is acetylcholine which, when released into the synaptic cleft, is quickly metabolized by acetylcholinesterase. This is the main mechanism that terminates the action of acetylcholine.
A) This enzyme catalyze the synthesis, not the metabolism, of acetylcholine.
B) This enzyme catalyze the metabolism of catecholamines.
C, E) These mechanisms are not involved in the termination of the action of acetylcholine.
Which of the following actions most likely results from the activation of autonomic autoreceptors?
Modulation of neurotransmitter release Inhibition of neurotransmitter reuptake Stimulation of enzyme synthesis Inhibition of enzyme synthesis Modulation of neurotransmitter storage
Modulation of neurotransmitter release
A receptor is defined as an “autoreceptor” when it modulates the release of the same neurotransmitter that activates it. In most cases this modulation results in an inhibition of the release (alpha-2 autoreceptors inhibit the release of norepinephrine, M2 autoreceptors inhibit the release of acetylcholine) but in a few cases there is a stimulation of the release (beta-2 autoreceptors stimulate the release of norepinephrine, Nn autoreceptors stimulate the release of acetylcholine).
Which of the following is a site where autonomic receptors are primarily α1 adrenergic?
Bronchial muscle Sphincter muscle of iris Atrioventricular node Purkinje fibers Skin vessels
Skin vessels
The vascular system has both α1 and β2 receptors. α1 receptors predominate in the vessels of the skin, gastrointestinal system and genitourinary system. β2 receptors predominate in the vessels of skeletal muscle and liver. Parasympathetic receptors are not widely represented in the vascular system.
Which of the following is a site where autonomic receptors are primarily α2 adrenergic? Uterus Lung Detrusor muscle Bladder internal sphincter Platelets
Platelets
Platelets have α2 receptors that can stimulate platelet aggregation. These receptors are not innervated but the increased plasma concentration of epinephrine and norepinephrine during the activation of the sympathetic nervous system increases the aggregation of platelets so improving the hemostasis. This is a good outcome in emergency situations because it helps to limit bleeding from wounds.
Which of the following is a site where autonomic receptors are primarily β1 adrenergic?
Gastric parietal cells
Radial muscle of iris
Ciliary epithelium
Juxtaglomerular cells
Juxtaglomerular cells
β1 receptors are abundant in juxtaglomerular cells and the activation of these receptors increases renin secretion.
A) Autonomic receptors in gastric parietal cells are primarily M3.
B) Autonomic receptors in the radial muscle of iris are primarily α1.
C) Autonomic receptors in the ciliary epithelium are primarily β2 and α2
