CH 7 Questions Flashcards
A 30-year-old woman undergoes abdominal surgery. In spite of minimal tissue damage, complete ileus (absence of bowel motility) follows, and she complains of severe bloating. She also finds it difficult to urinate. Mild cholinomimetic stimulation with bethanechol or neostigmine is often effective in relieving these complications of surgery. Neostigmine and
bethanechol in moderate doses have significantly different effects on which one of the following?
(A) Gastric secretory cells
(B) Vascular endothelium
(C) Salivary glands
(D) Sweat glands
(E) Ureteral tone
(B) Vascular endothelium
Parathion has which one of the following characteristics?
(A) It is inactivated by conversion to paraoxon
(B) It is less toxic to humans than malathion
(C) It is more persistent in the environment than DDT
(D) It is poorly absorbed through skin and lungs
(E) If treated early, its toxicity may be partly reversed by pralidoxime
(E) If treated early, its toxicity may be partly reversed by pralidoxime
Ms Brown has been treated for myasthenia gravis for several years. She reports to the emergency department complaining of recent onset of weakness of her hands, diplopia, and difficulty swallowing. She may be suffering from a change in response to her myasthenia therapy, that is, a cholinergic or a myasthenic crisis. Which of the following is the best drug
for distinguishing between myasthenic crisis (insufficient therapy) and cholinergic crisis (excessive therapy)?
(A) Atropine
(B) Edrophonium
(C) Physostigmine
(D) Pralidoxime
(E) Pyridostigmine
(B) Edrophonium
A crop duster pilot has been accidentally exposed to a high concentration of a highly toxic agricultural organophosphate insecticide. If untreated, the cause of death from such exposure would probably be
(A) Cardiac arrhythmia
(B) Gastrointestinal bleeding
(C) Heart failure
(D) Hypotension
(E) Respiratory failure
(E) Respiratory failure
Mr Green has just been diagnosed with dysautonomia (chronic idiopathic autonomic insufficiency). You are considering different therapies for his disease. Pyridostigmine and neostigmine may cause which one of the following in this patient?
(A) Bronchodilation
(B) Cycloplegia
(C) Diarrhea
(D) Irreversible inhibition of acetylcholinesterase
(E) Reduced gastric acid secretion
(C) Diarrhea
Parasympathetic nerve stimulation and a slow infusion of bethanechol will each
(A) Cause ganglion cell depolarization
(B) Cause skeletal muscle end plate depolarization
(C) Cause vasodilation
(D) Increase bladder tone
(E) Increase heart rate
(D) Increase bladder tone
Actions and clinical uses of muscarinic cholinoceptor agonists include which one of the following?
(A) Bronchodilation (treatment of asthma)
(B) Miosis (treatment of glaucoma)
(C) Decreased gastrointestinal motility (treatment of diarrhea)
(D) Decreased neuromuscular transmission and relaxation of skeletal muscle (during surgical anesthesia)
(E) Increased sweating (treatment of fever)
(B) Miosis (treatment of glaucoma)
Which of the following is a direct-acting cholinomimetic that is lipid-soluble and is used to facilitate smoking cessation?
(A) Acetylcholine
(B) Bethanechol
(C) Neostigmine
(D) Physostigmine
(E) Varenicline
(E) Varenicline
A 3-year-old child is admitted to the emergency department after taking a drug from her parents’ medicine cabinet. The signs suggest that the drug is an indirect-acting cholinomimetic with little or no CNS effect and a duration of action of about 2–4 h. Which of the following is the most likely cause of these effects?
(A) Acetylcholine
(B) Bethanechol
(C) Neostigmine
(D) Physostigmine
(E) Pilocarpine
(C) Neostigmine
Which of the following is the primary second-messenger process in the contraction of the ciliary muscle when focusing on near objects?
(A) cAMP (cyclic adenosine monophosphate)
(B) DAG (diacylglycerol)
(C) Depolarizing influx of sodium ions via a channel
(D) IP3 (inositol 1,4,5-trisphosphate)
(E) NO (nitric oxide)
(D) IP3 (inositol 1,4,5-trisphosphate)
