Block 5 Neuro Chemosensation Pain MCQ's
Questions and Answers
- 1.
A young neuroscientist has decided to investigate the best areas in the central nervous that enable the alleviation of pain. He delivers electrical stimulation via stereotactic implants into the CNS. Which of the following would most likely be responsible for the alleviation pain?
- A.
Inhibition of enkephalins in the substantia gelatinosa
- B.
Release of glutamate at the dorsal horn
- C.
Release of substance P at the dorsal horn
- D.
Stimulation of the raphe magnus neurons
- E.
Inhibition of opiates in the periaqueductal gray
Correct Answer
D. Stimulation of the raphe magnus neuronsExplanation
Stimulation of the raphe magnus neurons is most likely responsible for the alleviation of pain. The raphe magnus is a cluster of neurons located in the brainstem that is involved in pain modulation. When these neurons are stimulated, they release serotonin, which activates descending pain inhibitory pathways, leading to the alleviation of pain.Rate this question:
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- 2.
A 17~year-old girl presents with a bilateral loss of pain and thermal sensations at the base of the neck (C3 dermatome) and extending over the upper extremity and down to the level of the nipple (C4 to T4 dermatomes). MRI shows a cavitation in the spinal cord at these levels. Damage to which of the following structures would most likely explain this deficit?
- A.
Anterior white commissure
- B.
Left anterolateral system
- C.
Medial longitudinal fasciculus
- D.
Posterior columns
- E.
Right anterolateral system
Correct Answer
A. Anterior white commissureExplanation
The anterior white commissure is responsible for transmitting pain and temperature sensations across the midline of the spinal cord. Damage to this structure would result in a bilateral loss of pain and thermal sensations, which matches the symptoms described in the question. The other structures listed are not involved in transmitting pain and thermal sensations, so they would not explain the deficit.Rate this question:
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- 3.
A 92-year-old woman is brought to the emergency department by her caregiver. The woman had suddenly become drowsy and confused. The examination revealed no cranial nerve deficits and age-normal motor function, but a loss of pain, thermal, vibratory, and discriminative touch sensations on one side of the body excluding the head. CT shows a small infarcted area, (i) Which of the following structures is the most likely location of this lesion?
- A.
Anterolateral system
- B.
Medial geniculate nucleus
- C.
Subthalamic nucleus
- D.
Ventral posterolateral nucleus
- E.
Ventral posteromedial nucleus
Correct Answer
D. Ventral posterolateral nucleusExplanation
The most likely location of the lesion in this case is the ventral posterolateral nucleus. This is because the patient is experiencing a loss of pain, thermal, vibratory, and discriminative touch sensations on one side of the body excluding the head, which are all sensory functions that are processed in the ventral posterolateral nucleus. The absence of cranial nerve deficits and age-normal motor function suggests that the lesion is specific to the sensory pathways in this region.Rate this question:
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- 4.
A 92-year-old woman is brought to the emergency department by her caregiver. The woman had suddenly become drowsy and confused. The examination revealed no cranial nerve deficits and age-normal motor function, but a loss of pain, thermal, vibratory, and discriminative touch sensations on one side of the body excluding the head. CT shows a small infarcted area, (ii) The loss of pain and thermal sensations experienced by this woman would most likely correlate with a lesion involving which of the following structures?
- A.
Anterior (ventral) trigeminothalamic tract
- B.
Anterolateral system
- C.
Lateral lemniscus
- D.
Medial lemniscus
- E.
Spinal trigeminal tract
Correct Answer
B. Anterolateral systemExplanation
The anterolateral system is responsible for transmitting pain and temperature sensations from the body to the brain. In this case, the woman's loss of pain and thermal sensations on one side of the body suggests a lesion involving the anterolateral system. The other structures listed are not specifically involved in transmitting pain and thermal sensations.Rate this question:
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- 5.
The loss of pain and thermal sensation on the right side of the body reflects damage to which of the following fiber bundles or tracts?
- A.
Anterolateral system on the left
- B.
Anterolateral system on the right
- C.
Cuneate fasciculus on the left
- D.
Gracile fasciculus on the left
- E.
Posterior spinocerebellar tract on the left
Correct Answer
A. Anterolateral system on the leftExplanation
The loss of pain and thermal sensation on the right side of the body suggests damage to the anterolateral system on the left. The anterolateral system is responsible for carrying pain and temperature sensations from the opposite side of the body. Therefore, damage to the anterolateral system on the left would result in a loss of these sensations on the right side of the body.Rate this question:
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- 6.
An 80-year-old woman is brought to the emergency department from an assisted care facility. The woman, who is in a wheelchair, complains of not feeling well, numbness on her face, and being hoarse, although she claims not to have a cold. The examination reveals a loss of pain and thermal sensations on the right side of her face and the left side of her body. CT shows an infarcted area in the lateral portion of the medulla. A lesion of which of the following structures in this woman would explain the loss of pain and thermal sensations on her body excluding the head?
- A.
Anterolateral system on the left
- B.
Anterolateral system on the right
- C.
Medial lemniscus on the left
- D.
Spinal trigeminal nucleus on the left
- E.
Spinal trigeminal tract on the left
Correct Answer
B. Anterolateral system on the rightExplanation
The loss of pain and thermal sensations on the right side of the face and the left side of the body suggests a contralateral lesion. The anterolateral system is responsible for transmitting pain and thermal sensations, and it crosses over to the opposite side of the body at the level of the medulla. Therefore, a lesion in the anterolateral system on the right side would explain the loss of these sensations on the left side of the body.Rate this question:
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- 7.
A 65-year-old woman complains of brief attacks of intense pain on the right side of her face. Her physician prescribes carbamazepine, which significantly reduces recurrence of the painful attacks. What was the most likely diagnosis?
- A.
Thalamic pain
- B.
Lesion of the periaqueductal gray
- C.
Medial pontine syndrome
- D.
Lateral medullary syndrome
- E.
Trigeminal neuralgia
Correct Answer
E. Trigeminal neuralgiaExplanation
Trigeminal neuralgia is the most likely diagnosis in this case. Trigeminal neuralgia is characterized by brief attacks of intense pain on one side of the face, often triggered by activities such as eating or talking. Carbamazepine is a commonly prescribed medication for the treatment of trigeminal neuralgia, as it helps to reduce the recurrence of these painful attacks. Thalamic pain, lesion of the periaqueductal gray, medial pontine syndrome, and lateral medullary syndrome are not consistent with the symptoms described.Rate this question:
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- 8.
A 52-year old woman has had posterior spinal fusion with instrumentation and is recovering in the critical care unit. She has severe pain that has not been relieved with high doses of meperidine IM . What is a viable alternative? She is put on patient controlled analgesia using IV
- A.
Codeine
- B.
Meperidine
- C.
Dextromethorphan
- D.
Morphine
- E.
Tramadol
Correct Answer
D. MorphineExplanation
Morphine is a viable alternative for relieving severe pain in this patient. It is a potent opioid analgesic that is commonly used for managing moderate to severe pain. Since the patient has not experienced relief with high doses of meperidine IM, switching to morphine via patient controlled analgesia using IV administration can provide effective pain control. Morphine acts on the central nervous system to alleviate pain by binding to opioid receptors. It is a commonly used medication in postoperative pain management and is known for its strong analgesic properties.Rate this question:
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- 9.
A young neuroscientist has decided to Investigate the best areas in the central nervous that enable the alleviation of pain. He delivers electrical stimulation via stereotactic implants into the CNS. Which of the following would most likely be responsible for the alleviation pain?
- A.
Inhibition of enkephalins in the substantia gelatinosa
- B.
Release of glutamate at the dorsal horn
- C.
Release of substance P at the dorsal horn
- D.
Stimulation of the raphe magnus neurons
- E.
Inhibition of opiates in the periaqueductal gray
Correct Answer
D. Stimulation of the raphe magnus neuronsExplanation
Stimulation of the raphe magnus neurons would most likely be responsible for the alleviation of pain. The raphe magnus neurons are located in the brainstem and are known to be involved in pain modulation. When these neurons are stimulated, they release serotonin, which activates descending pain inhibitory pathways. This leads to the suppression of pain signals in the spinal cord, resulting in pain relief.Rate this question:
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- 10.
A 40-year old male has been diagnosed with bone cancer. His pain has been managed with a morphine pump implanted inside the skin, which has a catheter that runs into the spinal fluid space. However, recently he has developed tolerance to morphine. Which of the following drugs can be indicated to ameliorate his pain?
- A.
Naloxone
- B.
Meperidine
- C.
Codeine
- D.
Methadone
- E.
Fentanyl
Correct Answer
E. FentanylExplanation
Fentanyl can be indicated to ameliorate the patient's pain because it is a potent opioid analgesic that can provide effective pain relief. The patient has developed tolerance to morphine, so switching to a different opioid, such as fentanyl, can help overcome the tolerance and provide pain relief. Naloxone is not indicated because it is an opioid antagonist and would reverse the effects of the morphine pump. Meperidine and codeine are not as potent as fentanyl and may not provide sufficient pain relief. Methadone is an option, but fentanyl is often preferred due to its fast onset and short duration of action.Rate this question:
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- 11.
A 5-year old girl is admitted to the hospital after presenting with the following symptoms: low fever with persistent cough, and which has led to vomiting episodes after the persistent cough. Her throat culture is negative, her fever has resolved, but she has slight cough. Upon discharge from the hospital the pediatrician recommends an opioid antitussive. Which of the following drugs does the pediatrician recommend?
- A.
Naltrexone
- B.
Loperamide
- C.
Codeine
- D.
Propoxyphene
- E.
Naloxone
Correct Answer
C. CodeineExplanation
The pediatrician recommends codeine as an opioid antitussive for the 5-year old girl. Codeine is commonly used to suppress coughing and is effective in reducing cough symptoms. It can help alleviate the persistent cough that the girl is experiencing, which may have caused her vomiting episodes. The other options, such as Naltrexone, Loperamide, Propoxyphene, and Naloxone, are not typically used as antitussive medications and would not be the appropriate choice in this scenario.Rate this question:
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- 12.
Methadone has been used in the treatment therapy for opioid addiction. The ability of this drug to reduce the use of heroin and morphine by recovering addicts can be best explained by which of the following mechanisms?
- A.
Antagonism at the K opioid receptor
- B.
Blockade of the metabolic activation of heroin and morphine to their active forms
- C.
Antagonism at the mu opioid receptor
- D.
Antidepressant effects at serotonin (5-HT) receptors
- E.
Long-Iasting saturation of the mu opioid receptor and development of tolerance
Correct Answer
E. Long-Iasting saturation of the mu opioid receptor and development of toleranceExplanation
Methadone is useful in the treatment of opioid dependence. It has cross-tolerance with other opioids including heroin and morphine, offering very similar effects and a long duration of effect. Oral doses of methadone can stabilise patients by mitigating opioid withdrawal syndrome. Higher doses of methadone can block the euphoric effects of heroin, morphine, and similar drugs. As a result, properly dosed methadone patients can reduce or stop altogether their use of these substances.
As with other opioid medications, tolerance and dependence usually develop with repeated doses. There is some clinical evidence that tolerance to analgesia is less with methadone compared to other opioids; this may be due to its activity at the NA receptor. Tolerance to the different physiological effects of methadone varies; tolerance to both analgesic properties and euphoria develops quickly, whereas tolerance to constipation, sedation, and respiratory depression develops slowly (if ever).Rate this question:
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- 13.
Which of the following drugs has opioid antagonist action and can reduce nicotine and alcohol craving in persons addicted to those drugs?
- A.
Naloxone
- B.
Codeine
- C.
Fentanyl
- D.
Loperamide
- E.
Naltrexone
Correct Answer
E. NaltrexoneExplanation
Naltrexone is a drug that acts as an opioid antagonist, meaning it blocks the effects of opioids in the body. It can also reduce cravings for nicotine and alcohol in individuals addicted to those substances. This is because both nicotine and alcohol activate the brain's reward system, which involves the release of endorphins. Naltrexone blocks the effects of these endorphins, reducing the pleasurable sensations associated with nicotine and alcohol use and therefore reducing cravings.Rate this question:
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- 14.
A 17-year old female suffers a broken arm while training for a gymnastics competition. A cast is applied and she is discharged from the emergency room. She is prescribed an analgesic in case the acetaminophen or non-steroidal anti-inflammatory drugs are not effective in dealing with the pain relief. Which of the following is the best choice for prescription of pain relief?
- A.
Meperidine
- B.
Morphine
- C.
Methadone
- D.
Fentanyl
- E.
Codeine
Correct Answer
E. CodeineExplanation
Codeine is the best choice for prescription of pain relief in this case because it is a commonly used opioid analgesic that is effective in managing moderate to severe pain. It is often prescribed for pain relief after fractures and injuries. Codeine works by binding to opioid receptors in the brain and spinal cord, reducing the perception of pain. It is a relatively safe and well-tolerated medication when used as prescribed.Rate this question:
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- 15.
Jackson, a 65-year old male with type -II diabetes for 6 years, needs to undergo urologic surgery (trans-urethral resection). His surgeon decides to operate under epidural anesthesia. The drug is chosen from the opioid group of analgesics along with bupivacaine. This opioid acts on substantia gelatinasa of spinal cord. This drug most probably is
- A.
Oxycodone
- B.
Pentazocine
- C.
Propoxyphene
- D.
Fentanyl
- E.
Buprenorphine
Correct Answer
D. FentanylExplanation
Fentanyl is the most likely opioid drug chosen for Jackson's surgery because it acts on the substantia gelatinosa of the spinal cord and provides effective analgesia. Fentanyl is a potent opioid analgesic commonly used for surgical procedures, including urologic surgery. It has a rapid onset and short duration of action, making it suitable for epidural anesthesia. Oxycodone, pentazocine, propoxyphene, and buprenorphine are also opioids, but they do not specifically act on the substantia gelatinosa of the spinal cord like fentanyl does.Rate this question:
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- 16.
A 22-year old woman is taken into the emergency room. She is unconscious, has miosis, and depressed respiration. There are needle marks on her arms. In the emergency room the administration of an opioid antagonist produces an awakening effect on the patient. Which of the following drugs was most likely given to this patient?
- A.
Atropine
- B.
Buprenorphine
- C.
Propoxyphene
- D.
Naloxone
- E.
Flunadezil
Correct Answer
D. NaloxoneExplanation
The correct answer is Naloxone. Naloxone is an opioid antagonist that is used to reverse the effects of opioid overdose. The symptoms described in the question, including unconsciousness, miosis (constricted pupils), depressed respiration, and needle marks on the arms, are consistent with opioid overdose. Naloxone works by blocking the effects of opioids in the body, leading to an awakening effect in patients who have overdosed on opioids. Atropine is a medication used to treat certain types of poisoning and does not reverse the effects of opioids. Buprenorphine and propoxyphene are opioids themselves and would not produce an awakening effect in an overdose situation. Flunadezil is not a medication commonly used in emergency situations.Rate this question:
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- 17.
A 34-year-old male complains of ageusia (loss of taste sensation) from the left side of his tongue. Where is the most likely site of damage?
- A.
Left vagus nerve
- B.
Left nucleus of the solitary tract
- C.
Left facial nucleus
- D.
Right facial nerve
- E.
Left hypoglossal nerve
Correct Answer
B. Left nucleus of the solitary tractExplanation
The most likely site of damage in this case is the left nucleus of the solitary tract. The nucleus of the solitary tract is responsible for processing taste information from the tongue and relaying it to the brain. Damage to this nucleus on the left side would result in ageusia specifically from the left side of the tongue. The other options listed do not directly relate to taste sensation, making them less likely sites of damage.Rate this question:
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- 18.
Joe is a 53-year old male advertising executive who banged his head on the windscreen of his car in an automobile accident three weeks ago . At the time, he presented in the ER with watery discharge from the nose, which was identified as cerebrospinal fluid (CSF). After one week of hospitalization, his watery discharge stopped but Joe then observed that he had no sense of smell. Which clinical problem would best explain Joe's loss of smell sensation?
- A.
Fracture of the cribiform plate of the ethmoid bone
- B.
Stroke
- C.
Hysteria
- D.
Absence seizure
- E.
Factitious personality disorder
Correct Answer
A. Fracture of the cribiform plate of the ethmoid boneExplanation
Joe's loss of smell sensation is most likely due to a fracture of the cribiform plate of the ethmoid bone. The cribiform plate is a thin bone located at the roof of the nasal cavity, and it contains small holes through which the olfactory nerves pass. In Joe's case, the head trauma from the automobile accident could have caused a fracture in the cribiform plate, leading to damage or compression of the olfactory nerves. This would result in a loss of smell sensation.Rate this question:
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- 19.
The patient, Joe, in the previous question, has tenderness on his face. He was able to close his eyes, frown and smile; however he was unable to distinguish between coffee and soap. An X-ray of his face revealed a fracture of his cribiform plate. Based on the findings, this patient most likely has
- A.
Bell's palsy
- B.
Seizures
- C.
Dysgeusia
- D.
Hyposmia
- E.
Hyperosmia
Correct Answer
D. HyposmiaExplanation
The patient's inability to distinguish between coffee and soap suggests a problem with his sense of smell, which is known as hyposmia. The fracture of his cribiform plate, which is a part of the skull that separates the nasal cavity from the brain, is likely causing damage to the olfactory nerves responsible for the sense of smell. Therefore, hyposmia is the most likely diagnosis in this case.Rate this question:
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- 20.
Four weeks after a stroke that left a 66-year-old female patient paralyzed in the right lower half of the face only; she presented to her doctor with inability to clearly identify taste sensation on the left side of her tongue while still retaining the ability to respond emotionally to especially noxious substances. The doctor checked this complaint by giving her quinine to taste. Although she couldn't specifically describe the taste of quinine, she reacted to the taste in a way that suggested disgust. Which of the following best explains the pathophysiology of this presentation?
- A.
The stroke affected the primary somatosensory cortex and caused loss of conscious taste sensation
- B.
The stroke affected the cingulate gyrus and compromised patient's emotional response to taste
- C.
The stroke affected the premotor cortex and compromised the patient's psychomotor response to taste
- D.
The stroke affected the tractus solitarius in the brainstem and compromised conscious taste perception
- E.
The stroke damaged the insula while sparing the limbic cortex
Correct Answer
E. The stroke damaged the insula while sparing the limbic cortexExplanation
The insula is responsible for processing taste sensations, while the limbic cortex is involved in emotional responses. The fact that the patient retained the ability to respond emotionally to noxious substances suggests that the limbic cortex was unaffected. However, the patient was unable to clearly identify taste sensations on the left side of her tongue, indicating damage to the insula. This explains the presentation of the patient's symptoms after the stroke.Rate this question:
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- 21.
A 26-year old footballer collides with a member of the opposition during a soccer match. A couple of days later he meets with his physician and complains of hyposmia. Which of the following statements is correct in relation to normal olfaction?
- A.
Primary olfactory neurons are multipolar
- B.
The main output cell of the olfactory bulb is the mitral cell
- C.
Primary olfactory neurons synapse in specific glomeruli within the olfactory epithelium
- D.
Sustentacular cells are also known as Basal cells
- E.
Olfactory epithelium is located in the inferior nasal cavity
Correct Answer
B. The main output cell of the olfactory bulb is the mitral cellExplanation
The main output cell of the olfactory bulb is the mitral cell. This means that the signals received by the olfactory receptors in the nose are transmitted to the olfactory bulb, where the mitral cells then carry these signals to other parts of the brain for further processing and interpretation. This is an important step in the sense of smell, as it allows for the detection and recognition of different odors.Rate this question:
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- 22.
A 34-y/o male complains of ageusia (loss of taste sensation) from the left side of his tongue. Where is the most likely site of damage?
- A.
Left vagus nerve
- B.
Left nucleus of the solitary tract
- C.
Left facial nucleus
- D.
Right facial nerve
- E.
Left hypoglossal nerve
Correct Answer
B. Left nucleus of the solitary tractExplanation
The most likely site of damage in this case is the left nucleus of the solitary tract. The nucleus of the solitary tract is responsible for processing taste information from the tongue and relaying it to the brain. Damage to this nucleus on the left side would result in loss of taste sensation specifically from the left side of the tongue. The other options, such as the left vagus nerve, left facial nucleus, right facial nerve, and left hypoglossal nerve, are not directly involved in taste sensation and would not explain the symptoms of ageusia on the left side of the tongue.Rate this question:
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Mar 18, 2023Quiz Edited by
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Jan 24, 2012Quiz Created by
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