1.
What of the following is true about the Nicotinic Cholinergic Receptors in the Periphery
Correct Answer
E. All are true
Explanation
Nicotinic Cholinergic Receptors in the periphery are found on postganglionic neurons of the parasympathetic nervous system, they are ligand-gated ion channels, and they are also found at neuromuscular junctions of the somatic nervous system. Additionally, these receptors act as gates for sodium ions. Therefore, all of the statements given in the options are true about Nicotinic Cholinergic Receptors in the periphery.
2.
Which of the following are true about Muscarinic Cholinergic Receptors in the Periphery
Correct Answer
D. All are true
Explanation
Muscarinic Cholinergic Receptors in the Periphery have different subtypes, including M1, M2, M3, M4, and M5. M1, M3, and M5 receptors are mainly stimulatory and activate Gq proteins, while M2 and M4 receptors are mainly inhibitory and activate Gi proteins. These receptors are found in both sympathetic and parasympathetic sites. Therefore, all the statements given in the options are true.
3.
Autonomic nerve fibers plays a role in regulating
Correct Answer(s)
A. Blood pressure and flow
B. Metabolism
C. Blood glucose levels
D. Micturition and defecation
E. Pupillary light and accommodation reflexes
F. Glandular secretions
G. Bronchial dilation
H. Body temperature
I. Gastrointestinal movements and secretions
Explanation
The autonomic nerve fibers play a role in regulating various bodily functions including blood pressure and flow, metabolism, blood glucose levels, micturition and defecation, pupillary light and accommodation reflexes, glandular secretions, bronchial dilation, body temperature, and gastrointestinal movements and secretions. These functions are controlled by the autonomic nervous system, which consists of the sympathetic and parasympathetic divisions. The sympathetic division is responsible for the fight-or-flight response, while the parasympathetic division controls rest and digestion. The autonomic nerve fibers innervate various organs and tissues, allowing for the regulation of these important physiological processes.
4.
What are the actions of atropine. What is it used for?
Correct Answer
A. Compete with ACh for a common binding site on muscarinic receptors
Explanation
Atropine competes with acetylcholine (ACh) for a common binding site on muscarinic receptors. Muscarinic receptors are a type of receptor found in various tissues and organs in the body that are stimulated by ACh. By competing with ACh for binding to these receptors, atropine blocks the actions of ACh. This leads to inhibition of the parasympathetic nervous system, which is responsible for controlling various involuntary functions in the body. Atropine is used for a variety of purposes, including as an antidote for certain types of poisoning, to treat certain heart conditions, and to dilate the pupils during eye examinations.
5.
What are the effects of ACh on cardiovascular function?
Correct Answer
D. A and b
Explanation
ACh has both direct and indirect effects on cardiovascular function. The direct effect occurs through the activation of parasympathetic fibers, which leads to a decrease in cardiac output. The indirect effect is through the inhibition of NE secretion. Therefore, both options a and b are correct.
6.
What are the effects of ACh on heart function?
Correct Answer(s)
A. Decrease in cardiac force of contraction
B. Decreased heart rate
C. Vasodilation
D. Decreased conduction rate in SA and AV nodes
Explanation
ACh (acetylcholine) has multiple effects on heart function. It causes a decrease in cardiac force of contraction, meaning that the strength of the heart's contractions is reduced. It also leads to a decreased heart rate, slowing down the heart's rhythm. ACh causes vasodilation, which is the widening of blood vessels, allowing for increased blood flow. Additionally, it decreases the conduction rate in the SA (sinoatrial) and AV (atrioventricular) nodes, which are responsible for coordinating the electrical signals that regulate the heart's contractions. Therefore, ACh has an overall inhibitory effect on heart function.
7.
Muscarinic receptors are responsible for __________ are located on _____________
Correct Answer(s)
vasodilation, endothelial cells
Explanation
Muscarinic receptors are a type of receptor that are responsible for vasodilation, which is the widening of blood vessels. These receptors are located on endothelial cells, which are the cells that line the inner surface of blood vessels. When muscarinic receptors are activated, they cause a relaxation of the smooth muscle in the blood vessel walls, leading to vasodilation and increased blood flow.
8.
What are the nonselective ACh agonists
Correct Answer(s)
A. Carbechol
B. Arecoline
Explanation
The nonselective ACh agonists listed are carbachol and arecoline. These drugs activate both muscarinic and nicotinic receptors, leading to a wide range of effects in the body. Carbachol is commonly used in ophthalmology to decrease intraocular pressure in glaucoma. Arecoline, derived from the betel nut, has been used traditionally as a stimulant and to treat conditions like asthma and constipation. Both drugs have potential side effects due to their nonselective nature and should be used with caution.
9.
What are the muscarinic selective ACh agonists
Correct Answer(s)
C. Pilocarpine
D. Muscarine
E. Bethanechol
F. Methacholine
Explanation
The muscarinic selective ACh agonists are drugs that specifically activate muscarinic receptors in the body. Pilocarpine, muscarine, bethanechol, and methacholine are all examples of muscarinic selective ACh agonists. These drugs mimic the effects of acetylcholine, a neurotransmitter that plays a role in various bodily functions such as smooth muscle contraction, glandular secretion, and slowing of heart rate. By selectively targeting muscarinic receptors, these drugs can be used for various therapeutic purposes, such as treating glaucoma, stimulating gastrointestinal motility, or diagnosing bronchial hyperresponsiveness.
10.
Muscarinic receptor antagonists block muscarinic receptors on
Correct Answer(s)
A. Smooth muscle
B. Vascular muscle
C. Cardiac muscle
D. Gland cell
E. Peripheral ganglia
F. CNS
Explanation
Muscarinic receptor antagonists block muscarinic receptors on smooth muscle, vascular muscle, cardiac muscle, gland cells, peripheral ganglia, and the central nervous system (CNS). These receptors are part of the parasympathetic nervous system and are involved in controlling various bodily functions. By blocking these receptors, muscarinic receptor antagonists inhibit the effects of acetylcholine, the neurotransmitter that activates these receptors. This leads to a relaxation of smooth muscle, dilation of blood vessels, decreased heart rate, reduced glandular secretions, and inhibition of nerve impulses in peripheral ganglia and the CNS.
11.
Muscarinic receptor antagonists
Correct Answer
B. Decrease tone and motility of GI
Explanation
Muscarinic receptor antagonists are drugs that block the action of acetylcholine at muscarinic receptors in the body. These receptors are found in various organs, including the gastrointestinal (GI) tract. By blocking the muscarinic receptors in the GI tract, these antagonists decrease the tone (contraction) and motility (movement) of the GI muscles. This can result in a decrease in GI activity and slower movement of food through the digestive system. Therefore, the correct answer is that muscarinic receptor antagonists decrease tone and motility of the GI tract.
12.
Which of the sympathetic muscarinic receptor antagonists do not cross the BBB
Correct Answer(s)
A. Tiotropium
C. Ipratropium
E. Methylatropine
Explanation
Tiotropium, ipratropium, and methylatropine do not cross the blood-brain barrier (BBB). The blood-brain barrier is a protective barrier that prevents certain substances from entering the brain. These three drugs are sympathetic muscarinic receptor antagonists that are used to treat conditions such as asthma and chronic obstructive pulmonary disease. By not crossing the BBB, they primarily act on peripheral muscarinic receptors in the airways, reducing bronchoconstriction and improving airflow. Homatropine and tropicamide, on the other hand, are muscarinic receptor antagonists that can cross the BBB and are used primarily for their effects on the eye, such as dilating the pupil.
13.
Physiological Effects of Muscarinic Antagonists on the CNS
Correct Answer(s)
A. Cause euphoria; can also cause hallucination, delirium
B. Cause CNS depression (drowsiness, fatigue, amnesia, dreamless sleep, etc..)
C. Used in Parkinson’s disease as adjuncts to levodopa; also used to treat tardive dyskinesia
E. Cause mild vagus nerve excitation by stimulating medulla and higher brain centers
Explanation
Muscarinic antagonists have various physiological effects on the central nervous system (CNS). They can cause euphoria, hallucination, and delirium, which suggests their potential for altering mood and perception. Additionally, these antagonists can induce CNS depression, leading to symptoms such as drowsiness, fatigue, amnesia, and dreamless sleep. They are used as adjuncts to levodopa in Parkinson's disease and also for treating tardive dyskinesia. Furthermore, muscarinic antagonists can have a mild vagus nerve excitation effect by stimulating the medulla and higher brain centers.
14.
Cholinergic autonomic neurotransmission is mainly regulated by activation of ______________
Correct Answer(s)
nicotinic receptors
Explanation
Cholinergic autonomic neurotransmission is primarily regulated by the activation of nicotinic receptors. These receptors are located in the autonomic ganglia and adrenal medulla, where they mediate the effects of acetylcholine release. Upon activation, nicotinic receptors allow the influx of sodium ions, leading to depolarization and subsequent propagation of the nerve impulse. This ultimately results in the transmission of signals in the autonomic nervous system, which controls various involuntary bodily functions such as heart rate, digestion, and glandular secretions.
15.
Physiological Effects of Muscarinic Antagonists on the respiratory system inhibit _________ and _____________
Correct Answer(s)
secretions, bronchoconstriction
Explanation
Muscarinic antagonists inhibit secretions and bronchoconstriction in the respiratory system. These drugs block the action of acetylcholine on muscarinic receptors, which are found in the airways and glands of the respiratory system. By inhibiting secretions, muscarinic antagonists reduce the production of mucus in the airways, making it easier to breathe. Additionally, by blocking bronchoconstriction, these drugs help to relax the smooth muscles in the airways, widening them and improving airflow. Overall, the use of muscarinic antagonists can help alleviate symptoms of respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD).
16.
Ingestion of __________ is a major cause of poisoning
Correct Answer(s)
belladonna alkaloids
Explanation
Ingestion of belladonna alkaloids is a major cause of poisoning. Belladonna alkaloids are a group of toxic substances found in plants such as deadly nightshade (belladonna). These alkaloids can cause a range of symptoms including dilated pupils, dry mouth, blurred vision, rapid heartbeat, and even hallucinations. Ingesting these alkaloids in high amounts can lead to severe poisoning, which can be life-threatening. Therefore, the ingestion of belladonna alkaloids is considered a major cause of poisoning.
17.
Many drugs are ‘dirty’, and bind muscarinic receptors to produce unwanted effects:
Correct Answer(s)
A. Phenothiazines
B. Histamine H1 antagonists
C. Tricyclic antidepressants
E. Newer antipsychotic drugs
Explanation
The drugs mentioned in the answer (phenothiazines, histamine H1 antagonists, tricyclic antidepressants, and newer antipsychotic drugs) are known to bind muscarinic receptors and produce unwanted effects. This means that when these drugs interact with muscarinic receptors in the body, they can cause side effects or adverse reactions that are not desired.
18.
Acetylcholinesterase
-
Degrades ACh by ___________ , producing a choline and an acetate group
-
Active site composed of an _____ site and esteratic site that bind to ACh
-
Have very high catalytic activity
-
Degrade ___molecules of ACh/second/single AChE
Correct Answer(s)
hydrolysis, anionic, 25K
Explanation
Acetylcholinesterase degrades ACh through hydrolysis, breaking it down into choline and an acetate group. Its active site is composed of an anionic site and an esteratic site that bind to ACh. Acetylcholinesterase has very high catalytic activity, allowing it to degrade 25,000 molecules of ACh per second.
19.
What is true about reversible AChE inhibitors
Correct Answer(s)
A. Some have high affinity for the anionic site of AChE (edrophonium is prototype)
B. Acid transforming inhibitors bind to AChE and form an intermediate acid-enzyme compound
C. Carbamated AChE cannot hydrolyze ACh
Explanation
Reversible AChE inhibitors have several characteristics. Firstly, some of them, such as edrophonium, have a high affinity for the anionic site of AChE. Secondly, acid transforming inhibitors bind to AChE and form an intermediate acid-enzyme compound. Additionally, carbamated AChE inhibitors are unable to hydrolyze ACh. Lastly, reversible AChE inhibitors bind to the esteratic site of AChE and form a stable but inactive compound.
20.
What is true about irreversible AChE inhibitors
Correct Answer(s)
D. Bind AChE at the esteratic site
E. Form a stable but inactive compound
Explanation
Irreversible AChE inhibitors bind to the esteratic site of AChE, forming a stable but inactive compound. This means that once the inhibitor binds to the enzyme, it permanently deactivates it, preventing the hydrolysis of ACh. This is different from reversible AChE inhibitors, which can bind and unbind from the enzyme, allowing the enzyme to regain its activity. The statement about irreversible AChE inhibitors in the question aligns with this explanation.
21.
Reversible AChE Inhibitors
Correct Answer(s)
A. Carbamates and acridines
C. Tacrine
E. Phystostigmine
Explanation
The correct answer includes carbamates and acridines, tacrine, and phystostigmine. Reversible AChE inhibitors are substances that block the activity of the enzyme acetylcholinesterase, which breaks down the neurotransmitter acetylcholine. Carbamates and acridines are two classes of compounds that can reversibly inhibit AChE. Tacrine is a specific reversible AChE inhibitor used in the treatment of Alzheimer's disease. Phystostigmine is another reversible AChE inhibitor commonly used in the treatment of myasthenia gravis and glaucoma.
22.
Irreversible AChE Inhibitors
Correct Answer(s)
B. Nerve gases (sarin, tabun, soman
D. Carbaryl
Explanation
The correct answer is nerve gases (sarin, tabun, soman) and carbaryl. Nerve gases such as sarin, tabun, and soman are irreversible acetylcholinesterase (AChE) inhibitors, meaning they bind irreversibly to the AChE enzyme and inhibit its activity. This leads to the accumulation of acetylcholine in the synaptic cleft, resulting in overstimulation of cholinergic receptors and causing symptoms such as muscle paralysis, respiratory distress, and ultimately death. Carbaryl is also an irreversible AChE inhibitor, commonly used as a pesticide. It works by binding to and inhibiting the AChE enzyme, leading to the same effects as nerve gases but at a slower rate and lower potency.
23.
ACh inhibitor that
-
Synthetic, binds to anionic site
-
Does not cross BBB
-
Also has actions at nicotinic receptors in neuromuscular junctions
Correct Answer
C. Neostigmine
Explanation
Neostigmine is the correct answer because it is an ACh inhibitor that binds to the anionic site. It does not cross the blood-brain barrier (BBB) and also has actions at nicotinic receptors in neuromuscular junctions.
24.
ACh inhibitor that
-
Binds anionic site
-
Alkaloid made from the calabar bean
Correct Answer
B. Physostigmine
Explanation
Physostigmine is an ACh inhibitor that binds to the anionic site. It is an alkaloid derived from the calabar bean.
25.
ACh inhibitor that
-
Binds to anionic site and blocks ACh binding
-
Reversible inhibitor
Correct Answer
A. Edrophonium
Explanation
Edrophonium is a reversible ACh inhibitor that binds to the anionic site and blocks ACh binding. This means that it prevents the action of ACh by binding to the specific site on the receptor where ACh normally binds. As a reversible inhibitor, the effects of edrophonium can be reversed once it is no longer present, allowing ACh to bind to the receptor and restore normal function.
26.
Myasthenia gravis is an autoimmune disorder in which __________ receptors at the neuromuscular junction are attacked
Correct Answer
nicotinic
Explanation
Myasthenia gravis is an autoimmune disorder in which nicotinic receptors at the neuromuscular junction are attacked. This means that the immune system mistakenly targets and attacks the nicotinic receptors, which are responsible for transmitting signals from nerves to muscles. As a result, the communication between nerves and muscles is disrupted, leading to muscle weakness and fatigue.
27.
___________ poisoning is counteracted by physostigmine
Correct Answer
Belladonna
Explanation
Belladonna poisoning is counteracted by physostigmine. Belladonna, also known as deadly nightshade, contains toxic alkaloids that can cause symptoms such as dilated pupils, dry mouth, rapid heartbeat, and hallucinations. Physostigmine is an antidote that works by blocking the action of these toxic alkaloids, thereby reversing the symptoms of belladonna poisoning. It acts by inhibiting the enzyme responsible for breaking down acetylcholine, a neurotransmitter involved in various bodily functions. By increasing the levels of acetylcholine, physostigmine helps to restore normal physiological processes and counteract the effects of belladonna poisoning.
28.
AChE inhibitors are used to counteract ______ intoxication
Correct Answer
atropine
Explanation
AChE inhibitors are used to counteract atropine intoxication. Atropine is a medication that blocks the action of acetylcholine, a neurotransmitter in the nervous system. When atropine is administered in high doses, it can lead to symptoms such as increased heart rate, dry mouth, and dilated pupils. AChE inhibitors work by inhibiting the enzyme acetylcholinesterase, which breaks down acetylcholine. By inhibiting this enzyme, AChE inhibitors can increase the levels of acetylcholine in the body and counteract the effects of atropine intoxication.
29.
Tricyclic antidepressants in very high doses cause significant _______ receptor blockade
Correct Answer
muscarinic
Explanation
Tricyclic antidepressants in very high doses cause significant muscarinic receptor blockade. This means that these antidepressants, when taken in high amounts, can block the muscarinic receptors in the body. Muscarinic receptors are a type of receptor that are involved in various bodily functions, including the regulation of heart rate, smooth muscle contraction, and glandular secretions. Blocking these receptors can lead to side effects such as dry mouth, blurred vision, constipation, and urinary retention.
30.
AChE Inhibitors for Eye Conditions
Glaucoma
Correct Answer(s)
A. Reduce intraocular pressure by increasing ACh concentrations
B. Contraction of the ciliary body
C. Increase aqueous outflow
Explanation
AChE inhibitors for eye conditions, such as glaucoma, work by reducing intraocular pressure. They do this by increasing the concentration of acetylcholine (ACh), which leads to the contraction of the ciliary body and an increase in aqueous outflow. By increasing ACh concentrations, these inhibitors help to decrease the pressure inside the eye, which is beneficial for treating glaucoma.
31.
AChE Inhibitors for GI and Urinary Tract Disorders
-
Counteract smooth muscle inactivity (cause contractions)
-
Aid in bladder emptying by causing contractions of muscles associated with bladder
Correct Answer
A. True
Explanation
AChE inhibitors are known to counteract smooth muscle inactivity and cause contractions. In the context of GI and urinary tract disorders, these inhibitors can aid in bladder emptying by causing contractions of the muscles associated with the bladder. Therefore, the statement "AChE inhibitors for GI and urinary tract disorders counteract smooth muscle inactivity and aid in bladder emptying by causing contractions of muscles associated with the bladder" is true.
32.
AChE Inhibitors for GI and Urinary Tract Disorders
-
Counteract smooth muscle inactivity (cause dilations)
-
Aid in bladder emptying by causing dilations of muscles associated with bladder
Correct Answer
B. False
Explanation
The given answer is false. AChE inhibitors do not counteract smooth muscle inactivity or cause dilations. Instead, they inhibit the enzyme acetylcholinesterase, which leads to an accumulation of acetylcholine and increased cholinergic activity. This can have various effects on the body, but it does not directly cause dilations or aid in bladder emptying.
33.
One of hallmarks of Alzheimer’s is decreased ACh secretion
Correct Answer
A. True
Explanation
Alzheimer's disease is characterized by a decrease in the secretion of acetylcholine (ACh), which is a neurotransmitter involved in memory and cognition. This decrease in ACh secretion is one of the hallmarks of the disease and contributes to the cognitive decline observed in individuals with Alzheimer's. Therefore, the statement "One of the hallmarks of Alzheimer's is decreased ACh secretion" is true.
34.
One of hallmarks of Alzheimer’s is increased ACh secretion
Correct Answer
B. False
Explanation
The statement is false because one of the hallmarks of Alzheimer's disease is actually a decrease in acetylcholine (ACh) secretion, not an increase. Alzheimer's disease is characterized by the progressive loss of cholinergic neurons, which are responsible for producing and releasing ACh in the brain. This decrease in ACh levels leads to cognitive decline and memory loss, which are common symptoms of the disease. Therefore, the correct answer is false.
35.
Chronic fatigue is sometimes treated with _________, which crosses the BBB
Correct Answer
A. Galantamine
Explanation
Galantamine is sometimes used to treat chronic fatigue because it is able to cross the blood-brain barrier (BBB). The blood-brain barrier is a protective barrier that prevents certain substances from entering the brain. By crossing this barrier, galantamine is able to reach the brain and potentially alleviate symptoms of chronic fatigue. Tacrine, donepezil, and rivastigmine are not mentioned as being able to cross the BBB, so they may not be as effective in treating chronic fatigue.
36.
AChE Inhibitor Toxicities
Correct Answer(s)
A. Miosis
B. Salivation
C. Sweating
D. Vomiting
E. Bronchial constriction
Explanation
The given answer includes a list of symptoms that are associated with AChE inhibitor toxicities. AChE inhibitors are substances that inhibit the enzyme acetylcholinesterase, leading to an accumulation of acetylcholine in the body. This accumulation can result in various symptoms, including miosis (constriction of the pupils), salivation, sweating, vomiting, and bronchial constriction. These symptoms occur due to the overstimulation of the cholinergic system, which is responsible for various bodily functions.
37.
AChE Inhibitor Toxicities Treated by removing person from the poison then giving…
Correct Answer(s)
A. Atropine
B. Cholinesterase reactivators
Explanation
Atropine and cholinesterase reactivators are used to treat toxicities caused by acetylcholinesterase (AChE) inhibitors. AChE inhibitors block the breakdown of acetylcholine, leading to an accumulation of this neurotransmitter in the body. Atropine is used to counteract the effects of excess acetylcholine in the peripheral nervous system, while cholinesterase reactivators help restore the activity of AChE, allowing for the breakdown of acetylcholine. Parathion, tacrine, and distigmine are AChE inhibitors themselves and would not be used to treat toxicities caused by AChE inhibitors.