Midterm - Practice Questions Flashcards
Which type of major receptor is most associated with a “refractory period” after it is activated
a. G-protein coupled receptors
b. Voltage activated sodium channels
c. Nuclear hormone receptors (intracellular receptors)
d. Tyrosine kinase-associated receptors
Voltage activated sodium channels
The sulfonylurea (SUR1) receptor regulates the ATPdependent Na+ channel in pancreatic ℬ-cells
a. True
b. False
False
Induction of cytochrome P450 metabolizing enzymes can ____________ the metabolism of a drug, which will _____________ the elimination half life of a drug
a. increase; decrease
b. decrease; increase
c. increase; increase
d. decrease; decrease
Increase; decrease
Which receptor regulation term best describes “repeated or persistent drug-receptor interaction results in the removal of the receptor from the site (plasma membrane) of drug-receptor
interaction”
A. Desensitization
B. Tachyphylaxis
C. Down-regulation
Down-regulation
Regarding the graph below depicting a semi-logarithmic plot of plasma drug X concentration (Y axis) versus time (X axis) after intravenous administration of 500 mg; the approximate elimination half life is:
a. 2 hrs
b. 4 hrs
c. 8 hrs
d. 1 hr
4 hrs
(from 64 to 32ug/mL, from time 0 to 4 hrs)
- Which of the following statements about agonists and antagonists is MOST correct
A. Partial agonists are able to achieve the same maximal responses to full agonists with increased agonist concentrations
B. Negative allosteric modulators enhance agonist effects
C. Competitive receptor antagonists depress the maximal response or Emax value of the agonist
D. Non-receptor antagonists include chemical antagonists and physiologic antagonists
Non-receptor antagonists include chemical antagonists and physiologic antagonists
Which one of the following statements about the autonomic nervous system is FALSE?
a. Monoamine oxidase metabolizes norepinephrine
b. Acetylcholine is synthesized by the enzyme choline acetyltransferase
c. Activation of the sympathetic nervous system stimulates the secretion of epinephrine from the adrenal gland
d. All parasympathetic postganglionic neurons release acetylcholine
e. Activation of M2 receptors increases the rate and force of contraction of the heart
Activation of M2 receptors increases the rate and force of contraction of the heart
Which one of the following statements about autonomic drugs is TRUE?
a. Bethanechol is used to reduce the motility of the stomach or intestines
b. Epinephrine administration will contract smooth muscle in the bronchi
c. Dobutamine is an α2 receptor antagonist
d. Pilocarpine administration decreases blood pressure
e. Administration of muscarine will contract skeletal muscle
Pilocarpine administration decreases blood pressure
Which one of the following is an effect of a beta receptor antagonist?
a. Skeletal muscle contraction
b. Decreased heart rate
c. Bronchodilation
d. Increased intraocular pressure
e. Pupil dilation
Decreased heart rate
Which one of the following is an expected effect of a therapeutic dose of clonidine?
a. Decreased cAMP in presynaptic nerve terminals
b. Decreased DAG in intestinal smooth muscle
c. Increased cAMP in cardiac muscle cells
d. Increased cAMP in cells of the salivary gland
e. Increased EDRF release from endothelial cells that line blood vessels
Decreased cAMP in presynaptic nerve terminals
(b would also be accepted)
Which one of the following acts as a direct agonist at both nicotinic and muscarinic receptors?
a. Yohimbine
b. Atropine
c. Physostigmine
d. Acetylcholine
e. Butoxamine
Acetylcholine
Which one of the following statements is TRUE?
a. Dobutamine can be used to treat hypertension
b. Atropine will dilate the pupil without relaxing the ciliary muscle
c. Isoproterenol will increase heart rate and blood flow to skeletal muscle
d. Amphetamine administration will dilate blood vessels and decrease heart rate
e. Trimethaphan increases norepinephrine release and can activate adrenergic receptors directly
Isoproterenol will increase heart rate and blood flow to skeletal muscle
Which one of the following effects of norepinephrine would be blocked by prazosin but not by metoprolol?
a. Relaxation of gastrointestinal smooth muscle
b. Increased heart rate
c. Relaxation of smooth muscle cells in blood vessels
d. Dilation of the pupil
e. Relaxation of smooth muscle cells in the uterus
Dilation of the pupil
Blockers of α1 receptors can be used to treat which one of the following?
a. Asthma
b. Overactive bladder
c. Glaucoma
d. Hypertension
e. Anaphylactic shock
Hypertension
All of the following are symptoms of muscarinic excess EXCEPT:
a. Bronchodilation
b. Diarrhea
c. Constricted pupils
d. Sweating
e. Salivation
Bronchodilation
Which one of the following statements is FALSE?
a. Cocaine can be used to reduce local blood flow
b. Propranolol administration will reduce blood pressure
c. Bethanechol can be used to treat hypotension
d. Epinephrine can be used to treat cardiac arrest
e. Physostigmine can be used to treat glaucoma
Bethanechol can be used to treat hypotension
Match Trimethaphan with the appropriate use or effect
1. Muscarinic receptor antagonist
2. Can be used to treat glaucoma
3. Bronchodilator
4. Ganglionic blocker
5. Irreversible acetylcholinesterase
Ganglionic blocker
Match Echothiophate with the appropriate use or effect
1. Muscarinic receptor antagonist
2. Can be used to treat glaucoma
3. Bronchodilator
4. Ganglionic blocker
5. Irreversible acetylcholinesterase
Can be used to treat glaucoma
AND
Irreversible acetylcholinesterase inhibitor
Match Atropine with the appropriate use or effect
1. Muscarinic receptor antagonist
2. Can be used to treat glaucoma
3. Bronchodilator
4. Ganglionic blocker
5. Irreversible acetylcholinesterase
Muscarinic receptor antagonist
AND
Bronchodilator
Match Pilocarpine with the appropriate use or effect
1. Muscarinic receptor antagonist
2. Can be used to treat glaucoma
3. Bronchodilator
4. Ganglionic blocker
5. Irreversible acetylcholinesterase
Can be used to treat glaucoma
Match Albuterol with the appropriate use or effect
1. Muscarinic receptor antagonist
2. Can be used to treat glaucoma
3. Bronchodilator
4. Ganglionic blocker
5. Irreversible acetylcholinesterase
Bronchodilator
You perform the following experiment: you inject drug X into a tissue bath preparation that contains a section of gastrointestinal (GI) tract smooth muscle. Both parasympathetic and sympathetic nerve terminals are present in the tissue and the ganglia located closest to this piece of GI tract are still attached. In this experiment drug X produces a contraction.
(a) From the list of drugs provided below, which drug(s) might be causing the contraction?
acetylcholine, nicotine, trimethaphan, clonidine, yohimbine, isoproterenol.
acetylcholine, nicotine, yohimbine
Next you add trimethaphan to the tissue bath followed by the addition of drug X. In the presence of trimethaphan drug X still increases the contraction of the GI smooth muscle.
(b) From the list below, which drug(s) have you eliminated as a candidate for drug X?
acetylcholine, nicotine, yohimbine
nicotine
You switch tissue preparations. You are now using isolated skeletal muscle cells with no presynaptic input present. When you add drug X to this preparation the skeletal muscle cells contract.
(c) What is the identity of drug X?
acetylcholine, yohimbine
acetylcholine
How might the following symptoms have been induced?
Blurred vision:
inhibition of muscarinic receptors = dilation of pupil + relaxation of ciliary muscles = loss of accommodation
How might the following symptoms have been induced?
Heat prostration:
inhibition of muscarinic receptors on sweat glands = decreased secretion
What autonomic pathways & neurotransmitters normally regulate these physiological responses?
Blurred vision:
PSNS / ACh
What autonomic pathways & neurotransmitters normally regulate these physiological responses?
Heat prostration:
SNS/ ACh
What symptoms would indicate exposure to organophosphates?
symptoms of muscarinic excess + effects of increased ACh in the CNS, at ganglia and skeletal muscle
“dumbbels”
Diarrhea
Urination
Miosis
Bradycardia
Bronchoconstriction
Excitation (CNS)
Lacrimation
Sweating and salivation
In case of nerve gas exposure, military personnel are issued injectors containing atropine and pralidoxime. Why are atropine and pralidoxime used?
- atropine treats symptoms of muscarinic excess; short half life & does not help with nicotinic receptor effects
- pralidoxime removes the organophosphate from acetylcholinesterase
(a) Which of the following drugs causes relaxation?
acetylcholine, albuterol, atropine, clonidine, isoproterenol, nicotine
albuterol, atropine, clonidine, isoproterenol
You add propranolol to the tissue bath followed by the addition of drug X. Drug X no longer causes relaxation.
(b) Which drug (s) from the list below have you eliminated as a candidate for drug X?
albuterol, atropine, clonidine, isoproterenol
atropine, clonidine
You switch tissue preparations. You are now using isolated cardiac muscle cells with no presynaptic input. When you add drug X the cells contract.
(c) What is the identity of drug X?
albuterol, isoproterenol
isoproterenol
A child has swallowed the contents of a bottle of nasal decongestant containing an alpha receptor agonist. Which of the following symptoms would be observed?
a) Elevated blood pressure
b) Constriction of pupils
c) Increased urinary frequency
d) Increased gastric secretion
e) Sweating
Elevated blood pressure
What drug would inhibit the effect of elevated blood pressure caused by alpha receptor agonist consumption?
Prazosin
Local anaesthetics are used to alleviate pain and improve patient comfort in a number of procedures (eg. tooth extraction, wound cleaning, stitches, surgical procedures). For some procedures the duration of action of the anaesthetic may be too short. What autonomic drugs could be combined with the local anaesthetic to increase its duration of action?
Any drug that vasoconstricts (activate alpha1)
- direct agonists = norepinephrine, epinephrine, phenylephrine
- indirect agonists = cocaine, amphetamine, tyramine
Match Prazosin with the most appropriate effect or use listed below.
a. Can be used to treat hypertension in asthmatics
b. Long acting acetylcholinesterase inhibitor
c. Can be used to treat glaucoma
d. Decreases skeletal muscle contraction following exposure to organophosphates
e. Can be used to treat frequent urination
Can be used to treat hypertension in asthmatics
Match Atropine with the most appropriate effect or use listed below.
a. Can be used to treat hypertension in asthmatics
b. Long acting acetylcholinesterase inhibitor
c. Can be used to treat glaucoma
d. Decreases skeletal muscle contraction following exposure to organophosphates
e. Can be used to treat frequent urination
Can be used to treat frequent urination