NBME 13 Section 3 (Qst 1-50)

Reviewed by Editorial Team
The ProProfs editorial team is comprised of experienced subject matter experts. They've collectively created over 10,000 quizzes and lessons, serving over 100 million users. Our team includes in-house content moderators and subject matter experts, as well as a global network of rigorously trained contributors. All adhere to our comprehensive editorial guidelines, ensuring the delivery of high-quality content.
Learn about Our Editorial Process
| By Chachelly
C
Chachelly
Community Contributor
Quizzes Created: 513 | Total Attempts: 630,644
| Attempts: 2,676
Quiz Flashcard
SettingsSettings
Please wait...
  • 1/50 Questions

    A 35-year-old man who is a farmer is brought to the hospital by his wife because of difficulty breathing, sweating, excess salivation, and diarrhea for the past 2 hours. His wife says that the symptoms started when he was applying a new insecticide to his crops. Temperature is 36°C (96.8°F), pulse is 501min, respirations are 22/min, and blood pressure is 90/60 mm Hg. Which of the following is the most appropriate treatment?    

    • Atropine
    • Lpratropium
    • Mecamylamine
    • Neostigmine
    • Propantheline
Please wait...
About This Quiz

This NBME 13 Section 3 quiz evaluates medical knowledge and clinical decision-making skills through questions on various medical conditions and treatments, relevant for medical students preparing for the USMLE.

NBME 13 Section 3 (Qst 1-50) - Quiz

Quiz Preview

  • 2. 

    A 55-year-old man comes to the physician because of intermittent heartburn during the past 3 months. He says that he has approximately two episodes weekly during which he develops burning pain between his chest and abdomen when he lies down for a nap after dinner. A bitter taste sometimes accompanies the pain. He often has an alcoholic drink before dinner and several glasses of wine with the meal. He is 178 cm (5 ft 10 in) tail and weighs 113 kg (250 lb); BMI is 36 kg/m2. Physical examination shows no other abnormalities. In addition to weight loss and decreased alcohol consumption, which of the following drugs is most appropriate for this patient?

    • Loperamide

    • Misoprostol

    • Omeprazole

    • Prochlorperazine

    • Sucralfate

    Correct Answer
    A. Omeprazole
    Explanation
    The patient's symptoms of intermittent heartburn, especially after lying down and accompanied by a bitter taste, suggest gastroesophageal reflux disease (GERD). The patient's obesity and alcohol consumption are contributing factors to GERD. Omeprazole, a proton pump inhibitor, is the most appropriate drug for this patient as it reduces gastric acid secretion and provides relief from heartburn. Weight loss and decreased alcohol consumption are also important lifestyle modifications to manage GERD. Loperamide is an antidiarrheal, misoprostol is a prostaglandin analog used for preventing gastric ulcers, prochlorperazine is an antiemetic, and sucralfate is a mucosal protective agent, none of which are indicated for GERD.

    Rate this question:

  • 3. 
    A 35-year-old man has a 6-year history of weight loss, chronic abdominal pain, bloating, and frequent voluminous, greasy, malodorous stools. He had similar symptoms scan adolescent, but they resolved spontaneously within 2 years. His mother has a similar illness that is controlled by restricting wheat, barley, and rye in her diet. In addition to the gastrointestinal symptoms, the patient has a chronic pruritic rash shown in the photograph of his elbow. Which of the following is the most likely diagnosis of this patient's skin condition? - ProProfs

    A 35-year-old man has a 6-year history of weight loss, chronic abdominal pain, bloating, and frequent voluminous, greasy, malodorous stools. He had similar symptoms scan adolescent, but they resolved spontaneously within 2 years. His mother has a similar illness that is controlled by restricting wheat, barley, and rye in her diet. In addition to the gastrointestinal symptoms, the patient has a chronic pruritic rash shown in the photograph of his elbow. Which of the following is the most likely diagnosis of this patient's skin condition?

    • Bullous pemphigoid

    • Dermatitis herpetiforrnis

    • Epidermolysis bullosa

    • Erythema nodosum

    • Pemphigus vulgans

    Correct Answer
    A. Dermatitis herpetiforrnis
    Explanation
    The patient's symptoms of chronic abdominal pain, weight loss, and malodorous stools, along with a pruritic rash, are consistent with dermatitis herpetiformis (DH). DH is a skin manifestation of celiac disease, which is an autoimmune disorder triggered by gluten ingestion. The fact that the patient's mother also has a similar illness controlled by restricting wheat, barley, and rye in her diet further supports the diagnosis of DH. Bullous pemphigoid, epidermolysis bullosa, erythema nodosum, and pemphigus vulgaris are unrelated conditions and do not fit with the patient's symptoms.

    Rate this question:

  • 4. 

    A 35-year-old man comes to the physician because of a chronic cough for 5 months. He says, I worry I may have lung cancer like my dad." He has smoked 2 packs of cigarettes daily for 15 years. Physical examination and an x-ray of the chest show no abnormalities. After the physician informs the patient of the findings, which of the following responses is most appropriate to encourage this patient to quit smoking?   

    • "Have you ever considered changing to chewing tobacco?"

    • “Have you ever thought about quitting smoking?”

    • “I'd like to refer you to a hypnotist to help you quit smoking."

    • “I’ll prescribe some nicotine patches for you. That will help you cut down on your smoking."

    • “Try changing to low-nicotine cigarettes for a while. That will decrease your chances of getting lung cancer"

    • “You must stop smoking immediately, or you will most likely get lung cancer someday like your father.”

    Correct Answer
    A. “Have you ever thought about quitting smoking?”
    Explanation
    The most appropriate response to encourage the patient to quit smoking is to ask if they have ever thought about quitting. This response shows empathy and allows the patient to reflect on their smoking habit without being judgmental or forceful. It opens up a conversation about quitting smoking and allows the physician to provide information and support to the patient.

    Rate this question:

  • 5. 

    A 6-week-old male newborn has persistent nonbilious projectile vomiting. Physical examination shows prominent peristalsis. Laboratory findings are indicative of a metabolic alkalosis. Which of the following is the most likely mechanism of this condition?           

    • Aganglionosis of the large bowel

    • Congenital atresia of the bile ducts

    • Congenital defect in the diaphragm

    • Hypertrophy of the pyloric sphincter

    • Intestinal obstruction by meconium

    Correct Answer
    A. Hypertrophy of the pyloric sphincter
    Explanation
    The most likely mechanism of the newborn's condition is hypertrophy of the pyloric sphincter. This condition, known as pyloric stenosis, is characterized by the thickening and narrowing of the pyloric sphincter, which leads to difficulty in food passing from the stomach to the small intestine. The persistent nonbilious projectile vomiting and prominent peristalsis are typical clinical manifestations of pyloric stenosis. Metabolic alkalosis is also commonly seen in this condition due to the loss of hydrochloric acid through vomiting.

    Rate this question:

  • 6. 

    A healthy 56-year-old man comes to the physician for a pm-employment physical. Cardiac examination shows a systolic heart murmur that is best heard in the second interspace at the right sternal border and is transmitted to the carotid arteries. The murmur begins immediately after S1, rises in crescendo before falling in pitch, and ceases before S2. Which of the following is the most likely cause of the murmur?

    • Aortic stenosis

    • Atrial septal defect

    • Mitral regurgitation

    • Pulmonary regurgitation

    • Tricuspid stenosis

    Correct Answer
    A. Aortic stenosis
    Explanation
    The description of the murmur in this patient is consistent with a systolic ejection murmur, which is characteristic of aortic stenosis. The murmur is best heard in the second interspace at the right sternal border and is transmitted to the carotid arteries. The timing of the murmur, beginning immediately after S1 and ceasing before S2, is also consistent with aortic stenosis. Atrial septal defect, mitral regurgitation, pulmonary regurgitation, and tricuspid stenosis would not typically present with this specific pattern of murmur.

    Rate this question:

  • 7. 

    A 2-year-old girl is brought to the physician by her mother because of fever and a sore throat for 3 days. She has difficulty swallowing and has become irritable, listless, and uninterested in eating. She was recently adopted from a developing country, and her immunization history is unknown. Her temperature is 38.5°C (101.37), pulse is 150/min, and respirations are 40/min. Physical examination shows a dull red throat. A gray exudate is present on the tonsils, pharynx, uvula, and tongue, and the exudate can be lifted with a tongue blade. There is marked cervical lymphadenopathy. The most likely causal organism produces a toxin that causes ADP-ribosylation of which of the following targets?

    • Acetylcholinesterase

    • Adenylyl cyclase

    • Elongation factor-2

    • GTPase Gs subunit

    • Guanylyl cyclase

    • Ribosomal protein S1

    Correct Answer
    A. Elongation factor-2
    Explanation
    The most likely causal organism in this scenario is Group A Streptococcus, which produces a toxin called streptococcal pyrogenic exotoxin A (SpeA). This toxin causes ADP-ribosylation of elongation factor-2 (EF-2). ADP-ribosylation of EF-2 inhibits protein synthesis, leading to the characteristic symptoms of this infection, such as sore throat, fever, and difficulty swallowing. Acetylcholinesterase is not the target in this case, and the other options are not associated with the causal organism or its toxin.

    Rate this question:

  • 8. 

    An 8-year-old boy with severe mental retardation is brought to the physician because of a 1-year history of self-mutilating behavior, including biting his fingers. His male cousin has similar symptoms. Physical examination shows spasticity, chorea, and mutilation of the digits. Laboratory studies are most likely to show which of the following abnormalities?

    • Hypercalcemia

    • Hypercalciuria

    • Hyperuricemia

    • Hypokalemia

    • Hyponatremia

    • Hypophosphatemia

    Correct Answer
    A. Hyperuricemia
    Explanation
    The correct answer is hyperuricemia. In this case, the patient's self-mutilating behavior, along with the presence of spasticity, chorea, and mutilation of the digits, suggests the diagnosis of Lesch-Nyhan syndrome. This is a rare genetic disorder that results in the deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT), leading to the accumulation of uric acid. Hyperuricemia is a hallmark feature of this condition. Laboratory studies would likely show elevated levels of uric acid, confirming the diagnosis.

    Rate this question:

  • 9. 

    A 65-year-old man dies 4 days after complete occlusion of the left coronary artery. The left ventricle contains a large irregular area that is soft and pale. Which of the following processes is most likely responsible?         

    • Caseation necrosis

    • Coagulation necrosis

    • Dystrophic calcification

    • Fat necrosis

    • Gangrenous neCrOSIS

    • Liquefaction necrosis

    • Metastatic calcification

    Correct Answer
    A. Coagulation necrosis
    Explanation
    The most likely process responsible for the large irregular area in the left ventricle is coagulation necrosis. Coagulation necrosis occurs when there is a lack of blood supply to the tissue, leading to cell death. In this case, the complete occlusion of the left coronary artery would have caused ischemia and subsequent necrosis of the tissue in the left ventricle. The description of the area being soft and pale is consistent with coagulation necrosis.

    Rate this question:

  • 10. 

    A 15-year-old boy is brought tote physician by his mother because of a 2-month history of sneezing, coughing, and watery eyes immediately after he mows the lawn. Fifteen minutes after his symptoms first begin, he develops a red rash containing areas thatare soft to the touch. Physical examination shows boggy, soft, raised, pruritic, erythematous lesions with wheal and fiare eruptions over the face, trunk, and back. Which of the following describes the most likely underlying mechanism of the rash in this patient?

    • Type I (immediate) hypersensitivity

    • Type II (complement-mediated cytotoxic) hypersensitivity

    • Type III (immune complex-mediated) hypersensitivity

    • Type IV (delayed) hypersensitivity

    Correct Answer
    A. Type I (immediate) hypersensitivity
    Explanation
    The patient's symptoms of sneezing, coughing, watery eyes, and the development of a red rash immediately after mowing the lawn suggest an allergic reaction. The presence of soft, raised, pruritic, erythematous lesions with wheal and flare eruptions is characteristic of a type I (immediate) hypersensitivity reaction. Type I hypersensitivity reactions involve the release of histamine and other mediators from mast cells and basophils, resulting in the symptoms seen in this patient.

    Rate this question:

  • 11. 

    A 59-year-old man who has smoked 2 packs of cigarettes daily for 40 years develops an ulcerated laryngeal neoplasm. Examination of tissue obtained on biopsy of the lesion is most likely to show which of the following?

    • Adenocarcinoma

    • Reactive nodule

    • Squamous cell carcinoma

    • Squamous papilloma

    • Undifferentiated carcinoma

    Correct Answer
    A. Squamous cell carcinoma
    Explanation
    Based on the information provided, the 59-year-old man's smoking history is a significant risk factor for developing squamous cell carcinoma of the larynx. Smoking is strongly associated with the development of squamous cell carcinomas in various parts of the body, including the larynx. Therefore, it is most likely that the examination of the tissue obtained on biopsy of the ulcerated laryngeal neoplasm will show squamous cell carcinoma.

    Rate this question:

  • 12. 

    A 25-year-old man comes to the physician because of a 4-day history of pain and burning with urination and frequent urinary urgency. He is sexually active and has several female partners; he does not use condoms. His temperature is 37°C (98.6°F). Urinalysis shows 2+ protein; cultures grow on chocolate agar. A Gram stain shows gram-negative diplococci. The organism causing this patient’s symptoms most likely produces which of the following virulence factors?

    • Elementary bodies

    • Exotoxins

    • Free radicals

    • Pili

    • Spores

    Correct Answer
    A. Pili
    Explanation
    Although it does not produce any exotoxins, Neisseria gonorrhoeae has a wide range of virulence determinants. The first stages of infection, which includes adherence and invasion, are mediated by surface components. The bacterium first attaches to epithelial cells by means of its fimbriae, SPECIFICALLY N-METHYLPHENYLALANINE (TYPE IV) PILI, with the main subunit PilE. After initial attachment, the bacteria enter a second stage of binding mediated by the outer membrane protein P.II (also known as Opa) which is needed for tight binding and invasion of epithelial cells. Also, P.II from one bacterium will bind to LOS of an adjacent bacterium, which allows for the construction of a small colony that may function similarly to a biofilm. Neisseria gonorrhoeae also produces an IgA1 protease that may take part in the colonization stage.
    The outer membrane porin of N. gonorrhoeae P.I (also known as Por) is equivalent to the ompC and ompF porins of E. coli. They are involved in the passage of solutes through the outer membrane. However, P.I apparently has a role in virulence that allows the gonococci to survive inside of phagocytes. Purified P.I has also been shown to inhibit the ability of phagocytes to kill ingested bacteria. The lipooligosaccharide (LOS) is thought to be responsible for most of the symptoms of gonorrhea. Gonococcal LOS triggers an intense inflammatory response. The activation of complement, attraction and feeding by phagocytes, and the lysing of the phagocytes themselves, contributes to the purulent discharge. The local production of TNF is thought to be the main cause of damage to the fallopian tubes. In addition, in strains that cause systemic infection, LOS binds sialic acid from the serum forming a microcapsule of sialylated LOS, which allows the gonococci to resist the host immune response and serum bactericidal reaction

    Rate this question:

  • 13. 

    A 59-year-old woman with metastatic renal carcinoma is receiving cyclophosphamide, paclitaxel , and interleukin-2 (IL-2). Which of the following is the reason for including 1L-2 in the regimen?

    • Decreasing bone marrow suppression

    • Decreasing the likelihood of hemorrhagic cystitis

    • Decreasing the likelihood of peripheral neuropathy

    • Decreasing nausea and vomiting

    • Stimulating T lymphocytes

    Correct Answer
    A. Stimulating T lymphocytes
    Explanation
    The reason for including IL-2 in the regimen is to stimulate T lymphocytes. IL-2 is a cytokine that plays a crucial role in the activation and proliferation of T lymphocytes, which are important for the immune response against cancer cells. By stimulating T lymphocytes, IL-2 can enhance the immune system's ability to target and destroy cancer cells, potentially improving the outcome of the treatment.

    Rate this question:

  • 14. 

    A 73-year-old woman is brought to the physician because of a 1-month history of urinary frequency and urgency. She also has had a 3-month history of difficulties with walking, conversation. and memory. Neurologic examination shows normal strength and sensation. Her Mini-Mental State Examination score is 21/30. She walks with a wide-based, shuffling gait. A CT scan of the head shows marked enlargement of the ventricles. Which of the following is the most likely diagnosis?

    • Atherosclerosis of the carotid artery

    • Dementia, Alzheimer type

    • Huntington disease

    • Normal-pressure hydrocephalus E) Parkinson disease

    • Small vessel disease

    Correct Answer
    A. Normal-pressure hydrocephalus E) Parkinson disease
    Explanation
    The patient is presenting with urinary frequency and urgency, difficulties with walking, conversation, and memory, and a wide-based, shuffling gait. These symptoms, along with the marked enlargement of the ventricles seen on the CT scan, are consistent with normal-pressure hydrocephalus (NPH). NPH is characterized by the accumulation of cerebrospinal fluid in the ventricles, leading to increased pressure and enlargement of the ventricles. This can cause a triad of symptoms including urinary incontinence, gait disturbance, and cognitive decline. Parkinson's disease can also present with gait disturbance, but it is less likely in this case as the patient does not have any other characteristic symptoms of Parkinson's, such as tremor or rigidity.

    Rate this question:

  • 15. 

    A 5-month-old boy is brought to the physician because of a 5-day history of difficulty feeding. Physical examination shows macroglossia and enlargement of the anterior neck at the midline. A CT scan of the neck shows a 4-cm, well-defined, cystic structure. A remnant of which of the following is the most likely cause of this patient's condition?

    • Cervical sinus

    • First pharyngeal pouch

    • Fourth pharyngeal pouch

    • Occipital myotome

    • Thyroglossal duct

    Correct Answer
    A. Thyroglossal duct
    Explanation
    The patient's presentation of macroglossia and enlargement of the anterior neck at the midline is consistent with a thyroglossal duct cyst. The thyroglossal duct is a structure that connects the developing thyroid gland to the tongue during embryonic development. Normally, the thyroglossal duct obliterates and disappears by birth, but in some cases, it persists and can give rise to cysts. These cysts typically present as painless, midline neck masses that move with swallowing or protrusion of the tongue. CT scan findings of a well-defined, cystic structure further support the diagnosis of a thyroglossal duct cyst.

    Rate this question:

  • 16. 

    A 32-year-old man comes to the physician because of back pain and joint stiffness for 3 months. His symptoms improve after mild exercise. During this illness, he also has had fatigue and a 3.2-kg (7-1b) weight loss. Physical examination and x-rays of the sacroiliac joints confirm a diagnosis of ankylosing spondylitis. Which of the following laboratory tests would be most appropriate for the patient's two children to evaluate their susceptibility to this disease?

    • Analysis of class I MHC allele expression

    • Measurement of B-Iymphocyte mitogen responses to pokeweed mitogen

    • Measurement of T-Iymphocyte mitogen responses to phytohemaggiutinin

    • Polymerase chain reaction assay for bc1-2 gene expression

    • Polymerase chain reaction assay for tyrosine kinase gene expression

    Correct Answer
    A. Analysis of class I MHC allele expression
    Explanation
    Analysis of class I MHC allele expression would be most appropriate for the patient's two children to evaluate their susceptibility to ankylosing spondylitis. Ankylosing spondylitis is strongly associated with the human leukocyte antigen (HLA)-B27 allele, a class I MHC allele. Therefore, analyzing the expression of class I MHC alleles can help determine if the children have inherited the HLA-B27 allele and are at an increased risk of developing ankylosing spondylitis.

    Rate this question:

  • 17. 

    A 38-year-old woman is brought to the emergency department after being found lying on the sidewalk. She is conscious but says she is too weak to stand. Physical examination shows a red, swollen, tender tongue; angular stomatitis; and spoon-shaped nails. Hemoglobin and mean corpuscular volume are decreased. Which of the following is the most likely diagnosis?

    • Vitamin B12 (cobalamin) deficiency

    • Folic acid deficiency

    • Iron deficiency

    • Sickle cell disease

    • Vitamin B1 (thiamine) deficiency

    Correct Answer
    A. Iron deficiency
    Explanation
    The patient's presentation is consistent with iron deficiency anemia. The red, swollen, tender tongue and angular stomatitis are characteristic findings of iron deficiency. Spoon-shaped nails, known as koilonychia, are also commonly seen. Additionally, the decreased hemoglobin and mean corpuscular volume support the diagnosis of iron deficiency anemia. Vitamin B12 deficiency can cause similar symptoms, but it typically presents with neurological symptoms as well. Folic acid deficiency can cause megaloblastic anemia, but it does not typically cause the specific findings mentioned in the question. Sickle cell disease and vitamin B1 deficiency are not associated with the specific findings mentioned in the question.

    Rate this question:

  • 18. 

    A 60-year-old woman comes to the physician because of a 2-day history of flank pain and pain with urination. She has hypertension, recurrent urinary tract infections, and hypothyroidism. Her temperature is 37°C (98.6`F), pulse is 961min, and blood pressure is 152192 mm Hg. Physical examination shows no other abnormalities. Urinalysis shows 3+ blood, 1+ leukocytes, and few bacteria. Ultrasonography of the abdomen shows a large calculus filling the entire right renal pelvis. The renal calculus in this patient is most likely composed of which of the following substances?

    • Calcium oxalate

    • Cystine

    • Struvite

    • Uric acid

    Correct Answer
    A. Struvite
    Explanation
    The patient's history of recurrent urinary tract infections and the presence of 3+ blood, 1+ leukocytes, and few bacteria in the urinalysis suggest an infection-related stone. Struvite stones are commonly associated with urinary tract infections caused by urease-producing bacteria, which can hydrolyze urea to ammonia and increase the urine pH. The alkaline urine pH promotes the precipitation of magnesium ammonium phosphate crystals, leading to the formation of struvite stones. Therefore, the large calculus filling the right renal pelvis in this patient is most likely composed of struvite.

    Rate this question:

  • 19. 

    A 70-year-old woman comes to the physician because of several episodes of burning pain with urination during the past year. Physical examination shows uterine prolapse. Urinalysis shows a mild increase in leukocytes. Ultrasonography of the abdomen shows bilateral dilation of the renal collecting system. This patient is at greatest risk for which of the following?

    • Cervical carcinoma

    • Pyelonephritis

    • Renal cell carcinoma

    • Ureterolithiasis

    • Urotheliar carcinoma

    Correct Answer
    A. Pyelonephritis
    Explanation
    The patient's symptoms of burning pain with urination, uterine prolapse, and mild increase in leukocytes on urinalysis suggest a urinary tract infection (UTI). The ultrasonography findings of bilateral dilation of the renal collecting system indicate hydronephrosis, which is commonly seen in cases of UTI involving the upper urinary tract. Pyelonephritis, which is a bacterial infection of the kidneys, is the most likely diagnosis in this case. Therefore, the patient is at greatest risk for pyelonephritis.

    Rate this question:

  • 20. 

    A 26-year-old woman comes to the physician's office because of a 13.5-kg (30-1b) weight gain, irregular menstrual periods, constipation, and fatigue for the past 6 months. She also complains of increased difficulties with concentration and memory for the past month. Physical examination shows a blood pressure oil45/84 mm Hg, dry skin, and decreased muscle stretch reflexes at the ankles. Serum cholesterol concentration is 310 mg/dL, arid serum potassium concentration is 4.0 mEq/L, Determination of which of the following serum concentrations is most likely to confirm the diagnosis?

    • Cortisol

    • Dehydroepiandrosterone

    • Hemoglobin A1c

    • Luteinizing hormone

    • Prolactin

    • Testosterone

    • Thyroid-stimulating hormone

    Correct Answer
    A. Thyroid-stimulating hormone
    Explanation
    The patient's symptoms and physical examination findings are consistent with hypothyroidism. Hypothyroidism can cause weight gain, irregular menstrual periods, constipation, fatigue, difficulty with concentration and memory, dry skin, and decreased reflexes. The low blood pressure and high cholesterol are also associated with hypothyroidism. Thyroid-stimulating hormone (TSH) is the most appropriate test to confirm the diagnosis of hypothyroidism. In this case, an elevated TSH level would indicate primary hypothyroidism, where the thyroid gland is not producing enough thyroid hormone.

    Rate this question:

  • 21. 

        A 22-year-old man comes to the physician because of a 2-year history of episodes of shortness of breath and wheezing. His respirations are 12/min. Physical examination shows no abnormalities. It is found that the symptoms occur after he takes certain over-the-counter medications containing aspirin. Laboratory studies show a serum IgE concentration within the reference range and no eosinophilia. This patients symptoms are most likely caused by excessive production of which of the following substances?

    • Cyclooxygenase

    • Hydroxyeicosatetraenoic acid

    • Leukotrienes

    • Prostacyclin (PGI,)

    • Prostaglandins

    • Thromboxane A,

    Correct Answer
    A. Leukotrienes
    Explanation
    The patient's symptoms of shortness of breath and wheezing, which occur after taking certain over-the-counter medications containing aspirin, suggest that he may have aspirin-exacerbated respiratory disease (AERD). AERD is characterized by an excessive production of leukotrienes, which are inflammatory mediators involved in the pathogenesis of asthma. This excessive production is due to the dysregulation of the arachidonic acid pathway, leading to increased production of leukotrienes and decreased production of prostaglandins. The absence of eosinophilia and normal IgE levels in this patient further support the diagnosis of AERD. Therefore, the excessive production of leukotrienes is the most likely cause of this patient's symptoms.

    Rate this question:

  • 22. 

    An experimental model of treatment for sickle cell disease involves reactivating the genes that code for the chains of fetal hemoglobin. This treatment is most likely to increase the affinity of hemoglobin for which of the following?

    • 2,3-Bisphosphoglycerate

    • Carbon dioxide

    • Chloride ions

    • Oxygen

    • Protons

    Correct Answer
    A. Oxygen
    Explanation
    Reactivating the genes that code for the chains of fetal hemoglobin would increase the production of fetal hemoglobin. Fetal hemoglobin has a higher affinity for oxygen compared to adult hemoglobin. Therefore, this treatment is most likely to increase the affinity of hemoglobin for oxygen.

    Rate this question:

  • 23. 

    A 23-year-old woman comes to the physician because of a 3-week history of persistent cough that is worsened by the cold air in her drafty apartment. She does not smoke, takes no medications, and has no history of asthma or chronic pulmonary disease. Physical examination shows no abnormalities. Short-term cough suppressant treatment is initiated with a drug that does not cause constipation and has a low potential for substance abuse. This drug is most likely which of the following?

    • Codeine

    • Dextromethorphan

    • Hydromorphone

    • Oxycodone

    • Tramadol

    Correct Answer
    A. Dextromethorphan
    Explanation
    Dextromethorphan is the most likely drug for short-term cough suppressant treatment in this patient. It is a commonly used over-the-counter cough suppressant that does not cause constipation and has a low potential for substance abuse. Codeine, hydromorphone, oxycodone, and tramadol are opioids that can cause constipation and have a higher potential for substance abuse, making them less suitable for this patient. The patient's lack of smoking history, absence of asthma or chronic pulmonary disease, and normal physical examination findings further support the use of dextromethorphan as the appropriate choice.

    Rate this question:

  • 24. 
    A 36-year-aid man who is seropositive for HIV has had a nonproductive cough far 2 weeks. An x-ray of the chest shows a diffuse interstitial infiltrate. Silver stain of a lung biopsy specimen is shown. Which of the following is the most likely causal organism?             - ProProfs

    A 36-year-aid man who is seropositive for HIV has had a nonproductive cough far 2 weeks. An x-ray of the chest shows a diffuse interstitial infiltrate. Silver stain of a lung biopsy specimen is shown. Which of the following is the most likely causal organism?            

    • Candida tropicalis

    • Coccidoides Immitis

    • Cryptococcus neoformans

    • Cytomegalovirus

    • Mycobacterium tuberculosis

    • Pneumocystis jiroveci ( formerly P. carnii )

    Correct Answer
    A. Pneumocystis jiroveci ( formerly P. carnii )
    Explanation
    The most likely causal organism in this case is Pneumocystis jiroveci (formerly P. carinii). This is indicated by the patient's seropositivity for HIV, which puts them at a higher risk for opportunistic infections. Pneumocystis jiroveci is a common opportunistic infection in individuals with HIV and can cause a nonproductive cough and diffuse interstitial infiltrate on chest x-ray. The silver stain of the lung biopsy specimen would likely show characteristic cysts or trophozoites of Pneumocystis jiroveci, confirming the diagnosis.

    Rate this question:

  • 25. 

    A 19-year-old woman comes to the physician because of increasingly severe pain in the right hip during the past month. She has a 4-year history of refractory inflammatory bowel disease with arthritis in the hands treated with corticosteroids for the past 2 years, An x-ray of the pelvis shows collapse of the superior half of the right femoral head with preservation of the articular cartilage. The left hip appears normal. Which of the following is the most likely cause of the hip abnormality?

    • Ankylosing spondylitis

    • Aseptic necrosis

    • Gouty arthritis

    • Multiple myeloma

    • Septic arthritis

    Correct Answer
    A. Aseptic necrosis
    Explanation
    The most likely cause of the hip abnormality in this 19-year-old woman is aseptic necrosis. Aseptic necrosis, also known as avascular necrosis, is the death of bone tissue due to a lack of blood supply. It can be caused by corticosteroid use, which this patient has been taking for her refractory inflammatory bowel disease. The x-ray findings of collapse of the superior half of the right femoral head with preservation of the articular cartilage are consistent with aseptic necrosis. Ankylosing spondylitis, gouty arthritis, multiple myeloma, and septic arthritis are less likely causes in this clinical scenario.

    Rate this question:

  • 26. 

    A 33-year-old woman comes to the physician 3 days after she found a mass in her right breast on self-examination. Examination of the right breast shows a 2.5-cm, hard mass in the upper outer quadrant of the right breast. A photograph of the resected mass is shown. Which of the following characteristics of the lesion best predicts this patient's prognosis?

    • Degree of differentiation of the cells comprising the lesion

    • DNA content of the cells comprising the lesion

    • Lymph node involvement by cells originating in the lesion

    • Presence or absence of hormone receptors within the lesion

    • Size of the lesion

    Correct Answer
    A. Lymph node involvement by cells originating in the lesion
    Explanation
    Lymph node involvement by cells originating in the lesion is the best predictor of prognosis in this case. Lymph node involvement indicates that the cancer cells have spread beyond the breast and into the lymphatic system, increasing the risk of metastasis to other parts of the body. This suggests a more advanced stage of breast cancer and a poorer prognosis. The other characteristics listed may also be important factors in determining prognosis, but lymph node involvement is considered a stronger predictor.

    Rate this question:

  • 27. 

    A 95-year-old man who is a resident de skilled nursing care facility is brought to the emergency department because of a 1-day history of temperatures to 39.4°C (102.9°F), headache, cough, and muscle aches. Several other residents have similar symptoms. Physical examination shows no other abnormalities. Treatment with a neuraminidase inhibitor is begun. This drug most likely will inhibit which of the following processes, therefore decreasing the duration of this patent's symptoms?

    • Nucleocapsid-matiix protein interactions

    • Release of virus from infected epithelial cells

    • Replication of genomic RNA

    • Synthesis of surface glycoproteins

    • Transcription of TRNA

    Correct Answer
    A. Release of virus from infected epithelial cells
    Explanation
    The correct answer is "Release of virus from infected epithelial cells." This is because a neuraminidase inhibitor is a medication that specifically targets and inhibits the neuraminidase enzyme, which is responsible for the release of newly formed virus particles from infected cells. By inhibiting this process, the spread of the virus can be limited, leading to a decrease in the duration of the patient's symptoms.

    Rate this question:

  • 28. 

    A 49-year-old man is brought to the emergency department 30 minutes after fainting in the street. He regained consciousness 1 minute after fainting. He says that he has had watery diarrhea during the past 5 days, which has not improved with fasting. He has not changed his diet or travelled overseas recently. His blood pressure is 90160 mm Hg. Physical examination shows a flushed face and dehydration. Serum studies show a potassium concentration of 2 mEg/L and glucose concentration of 150 mg/dL. He is admitted to the hospital, and intravenous fluid replacement is started. Over the next day, he passes a stool with a volume of 3.5 L. Which of the following is the most likely cause of this patients diarrhea?

    • Bacterial overgrowth

    • Cholera

    • Inactivation of lipase

    • Lactose intolerance

    • Vasoactive intestinal polypeptide secretion

    Correct Answer
    A. Vasoactive intestinal polypeptide secretion
    Explanation
    The patient's symptoms of watery diarrhea, flushing, and dehydration, along with the low potassium concentration and high stool volume, are consistent with vasoactive intestinal polypeptide (VIP) secretion. VIP is a hormone that stimulates intestinal secretion and vasodilation, leading to increased fluid and electrolyte secretion in the intestines. This results in watery diarrhea and dehydration. Bacterial overgrowth, cholera, inactivation of lipase, and lactose intolerance do not typically cause such severe and prolonged watery diarrhea.

    Rate this question:

  • 29. 

    A 22-year-old nulligravid woman develops right flank pain 3 days after undergoing an appendectomy and right ovarian resection because of an appendiceal abscess. Menses occur at regular 28-day intervals. Vital signs are within normal limits. Physical examination shows mild right flank tenderness. The most likely cause of this patient's pain is the accidental ligation of which of the following structures on the right?

    • Ovarian artery

    • Ovarian vein

    • Renal artery

    • Renal vein

    • Ureter

    • Uterine ligament

    Correct Answer
    A. Ureter
    Explanation
    The most likely cause of the patient's pain is the accidental ligation of the ureter on the right. This is because the patient developed right flank pain after the surgery, and physical examination showed mild right flank tenderness. The ureter is a tube that carries urine from the kidneys to the bladder, and ligation of the ureter can cause obstruction and lead to pain in the affected area.

    Rate this question:

  • 30. 

    A 47-year-old woman comes to the physician because she wants to "do something about my wrinkles." Physical examination shows fine wrinkles in photodamaged skin on the face. Treatment with tretinoin is started. Collagen synthesis will most likely be increased in this patient by which of the following mechanisms?

    • Activation of nuclear gene transcription

    • Decreased CAMP production

    • Displaced vitamin A from cellular stores

    • Increased sebum production

    • Protection of keratinocytes from UVB irradiation

    Correct Answer
    A. Activation of nuclear gene transcription
    Explanation
    Tretinoin is a retinoid that works by activating nuclear gene transcription. It binds to retinoic acid receptors in the nucleus of cells, leading to increased gene expression. This increased gene expression promotes collagen synthesis, which can help improve the appearance of wrinkles in photodamaged skin. The other answer choices are not directly related to collagen synthesis.

    Rate this question:

  • 31. 

    A 92-year-old man is brought to the emergency department because of a 6-hour history of chest pain and shortness of breath. A diagnosis of congestive heart failure is made. Diuretic therapy is initiated, and his symptoms resolve over the next 3 days. However, his pulse remains at 44(min, and he has fatigue with minimal exertion. His physician believes that he should receive a pacemaker, however, the patient has expressed a desire to forego all invasive procedures. The physician presents the benefits of the pacemaker fully, but he describes the risks and follow-up in a cursory manner. The patient consents to the procedure. This physician has violated which of the following ethical principles?

    • Beneficence

    • Informed consent

    • Justice

    • Nonmaleficence

    • Veracity

    Correct Answer
    A. Informed consent
    Explanation
    The physician violated the principle of informed consent. Informed consent requires that the patient be provided with all relevant information about a medical procedure, including its benefits, risks, and alternatives, in order to make an informed decision. In this case, the physician only provided cursory information about the risks and follow-up of the pacemaker procedure, which does not meet the standard of informed consent.

    Rate this question:

  • 32. 

    A 63-year-old woman comes to the physician because of a 2-month history of a drooping left eyelid, intermittent pain of her left eye, and an unusually large pupil. Her husband has told her that the eye appears to be "looking sideways." Ophthalmologic examination shows ptosis, lateral strabismus, and mydriasis of the left eye. An MRI of the brain shows an aneurysm of the left posterior communicating artery. The function of which of the following muscles is most likely to remain intact in this patient?

    • Ciliary

    • Inferior oblique

    • Inferior rectus

    • Pupillary constrictor

    • Superior oblique

    • Superior rectus

    Correct Answer
    A. Superior oblique
    Explanation
    The superior oblique muscle is most likely to remain intact in this patient. The patient's symptoms, including ptosis, lateral strabismus, and mydriasis, are consistent with damage to the oculomotor nerve (cranial nerve III). The oculomotor nerve innervates most of the extraocular muscles, including the superior rectus, inferior rectus, inferior oblique, and pupillary constrictor muscles. However, the superior oblique muscle is innervated by the trochlear nerve (cranial nerve IV), which is not affected in this patient. Therefore, the superior oblique muscle is the only muscle listed that would remain intact in this patient.

    Rate this question:

  • 33. 

    A 76-year-old woman who is a resident of a skilled nursing care facility is brought to the physician because of a 2-day history of fever and cough. Her temperature is 38.5°C (10f .3°F). Treatment with ciprofloxacin is begun. Two days later, she is admitted lathe hospital because of a progressive cough and a temperature of 39°C (102.2°F). Culture of sputum at this time grows Streptococcus pneumoniae. A mutation in genes encoding which of the following enzymes is the most likely cause of the organism's resistance to ciprofloxacin?

    • Acetyl transferase

    • DNA gyrase

    • B-Lactamase

    • Tetrahydrofolate reductase

    • Transpeptidase

    Correct Answer
    A. DNA gyrase
    Explanation
    The correct answer is DNA gyrase. DNA gyrase is the target enzyme of ciprofloxacin, an antibiotic from the fluoroquinolone class. It is responsible for introducing negative supercoils into bacterial DNA, which is essential for DNA replication and transcription. Mutations in the genes encoding DNA gyrase can lead to resistance to ciprofloxacin, as the antibiotic is no longer able to bind and inhibit the enzyme effectively. This allows the bacteria, in this case Streptococcus pneumoniae, to survive and continue to cause infection despite treatment with ciprofloxacin.

    Rate this question:

  • 34. 
    A 25 year-old woman with obstructive sleep apnea comes to the physician because of oily, fatty bowel movements since starting a drug 1 month ago to aid in weight loss. She has had a 5- kg (11lb) weight loss during this period. She is 157 cm (5 ft 2 in) tall and now weighs 66 kg (145 lb); BMI is 27 kg/m2. Her blood pressure is 130/80 mm Hg; it was 140/85 mm Hg ether last visit 1 month ago. Physical examination shows no other abnormalities. The results of serum lipid studies done 1 month ago and at this visit are shown. Which of the following drugs is the most likely cause of the steatorrhea and changes in lipid serum studies in this patient?            - ProProfs

    A 25 year-old woman with obstructive sleep apnea comes to the physician because of oily, fatty bowel movements since starting a drug 1 month ago to aid in weight loss. She has had a 5- kg (11lb) weight loss during this period. She is 157 cm (5 ft 2 in) tall and now weighs 66 kg (145 lb); BMI is 27 kg/m2. Her blood pressure is 130/80 mm Hg; it was 140/85 mm Hg ether last visit 1 month ago. Physical examination shows no other abnormalities. The results of serum lipid studies done 1 month ago and at this visit are shown. Which of the following drugs is the most likely cause of the steatorrhea and changes in lipid serum studies in this patient?           

    • Atorvastatin

    • Bupropion

    • Orlistat

    • Phentemine

    • Sibutramine

    Correct Answer
    A. Orlistat
    Explanation
    Orlistat is the most likely cause of the steatorrhea and changes in lipid serum studies in this patient. Orlistat is a weight loss medication that works by inhibiting pancreatic lipase, the enzyme responsible for breaking down dietary fats. This leads to decreased absorption of fat in the intestines, resulting in oily, fatty bowel movements (steatorrhea). The weight loss and changes in lipid serum studies can be attributed to the decreased absorption of dietary fats.

    Rate this question:

  • 35. 

    A 25-year-old medical student whose father had alcoholism and died of cirrhosis initially gets angry at patients with alcoholism. Over the course of training, he continues to recognize that working with these types of patients is distressing to him, but he learns methods of dealing more effectively with them. Which of the following mental mechanisms best describes his ability to effectively control his emotions?

    • Denial

    • Projection

    • Reaction ton-nation

    • Repression

    • Suppression

    Correct Answer
    A. Suppression
    Explanation
    The medical student's ability to effectively control his emotions by recognizing and dealing with his distress when working with patients with alcoholism suggests the mental mechanism of suppression. Suppression involves consciously pushing unwanted thoughts, feelings, or impulses out of awareness in order to cope with them. In this case, the student acknowledges his distress and actively learns methods to deal with it, indicating a conscious effort to suppress his negative emotions and work more effectively with these patients.

    Rate this question:

  • 36. 

    A 76-year-old man with congestive heart failure comes to the physician because of a 1-month history of shortness of breath after walking up a flight of stairs. He has had frequent nausea, and he has had to use two pillows to sleep during this period.  Diffuse, moist crackles are heard over bath lungs. There is pitting edema above the ankles. Which of the following best describes the function of the product secreted by the atrial myocytes in this patient?

    • Decreased glomerular filtration rate

    • Increased sodium reabsorption

    • Induction of vasoconstriction

    • Inhibition of renin release

    • Stimulation of aldosterone release

    Correct Answer
    A. Inhibition of renin release
    Explanation
    The correct answer is "Inhibition of renin release." In congestive heart failure, there is increased fluid volume and pressure in the atria. Atrial myocytes secrete atrial natriuretic peptide (ANP) in response to this increased pressure. ANP acts to counterbalance the effects of the renin-angiotensin-aldosterone system by inhibiting the release of renin from the kidneys. This leads to decreased levels of angiotensin II and aldosterone, which helps to reduce fluid retention and lower blood pressure.

    Rate this question:

  • 37. 

    A 25-year-old man receives a bupivacaine injection for median nerve block as treatment of camel tunnel syndrome. Which of the following is the mechanism of action of this drug on the membrane?      

    • Activation of the Na+/K+ ATPase

    • Decreased permeability to Ca++,

    • Decreased permeability to Na+

    • Increased reuptake glutamate

    • Inhibition of the Na+/Ca++ antiporter

    Correct Answer
    A. Decreased permeability to Na+
    Explanation
    Bupivacaine is a local anesthetic that works by blocking sodium channels in the cell membrane. By decreasing the permeability to sodium ions (Na+), bupivacaine prevents the generation and conduction of nerve impulses, leading to numbness and loss of sensation in the area where it is injected. This mechanism of action explains how bupivacaine can effectively block the transmission of pain signals in the median nerve, providing relief for carpal tunnel syndrome.

    Rate this question:

  • 38. 

    A 32-year-old man has had generalized band-like headaches and dizziness almost every day for the past 6 months. Physical examination and CT scan of the head show no abnormalities. Which of the following additional findings in this patient is consistent with a diagnosis of hypochondriasis rather than undifferentiated somatoform disorder?          

    • Disproportionate fear of serious disease

    • Frequent health care visits

    • Past history of unexplained symptoms

    • Persistence of symptoms longer than 6 months

    • Presence of depressive symptoms

    Correct Answer
    A. Disproportionate fear of serious disease
    Explanation
    The presence of a disproportionate fear of serious disease is consistent with a diagnosis of hypochondriasis rather than undifferentiated somatoform disorder. Hypochondriasis is characterized by excessive worry and fear about having a serious medical condition, despite having little or no medical evidence to support the belief. This disproportionate fear is a key feature of hypochondriasis and distinguishes it from undifferentiated somatoform disorder, which is characterized by physical symptoms without a clear medical explanation. The other options, such as frequent health care visits, past history of unexplained symptoms, persistence of symptoms longer than 6 months, and presence of depressive symptoms, may be common in both hypochondriasis and undifferentiated somatoform disorder and do not specifically differentiate between the two.

    Rate this question:

  • 39. 

    A 1-year-old girl is brought to the physician because of multiple bacterial infections since birth. She is at the 40th percentile for length and 40th percentile for weight. She has white hair, pale skin, blue irises, and prominent red pupils. A complete blood count shows neutropenia. A peripheral smear shows giant granules in the neutrophils. This patient's disorder is most likely due to which of the following pathogenetic mechanisms?

    • Bone marrow suppression

    • Defect in leukocyte adhesion

    • Defect in phagolysosome function

    • Myeloperoxidase deficiency

    • NADPH oxidase deficiency

    Correct Answer
    A. Defect in phagolysosome function
    Explanation
    This patient's disorder is most likely due to a defect in phagolysosome function. The clinical presentation of multiple bacterial infections since birth, along with neutropenia, suggests an immunodeficiency disorder. The presence of giant granules in the neutrophils indicates a defect in phagolysosome function, which is responsible for the intracellular killing of bacteria. This defect can lead to recurrent bacterial infections. Bone marrow suppression, defect in leukocyte adhesion, myeloperoxidase deficiency, and NADPH oxidase deficiency are not consistent with the clinical findings in this patient.

    Rate this question:

  • 40. 
    An autopsy is done on a 50-year-old man who died of pneumonia despite 5 days of antibiotic therapy in the intensive care unit. He had a 15-year history of alcoholism. A photograph of a sagital section of the brain is shown, Based on this pathology, which of the following findings was most likely present on neurologic examination of the patient prior to his death? - ProProfs

    An autopsy is done on a 50-year-old man who died of pneumonia despite 5 days of antibiotic therapy in the intensive care unit. He had a 15-year history of alcoholism. A photograph of a sagital section of the brain is shown, Based on this pathology, which of the following findings was most likely present on neurologic examination of the patient prior to his death?

    • Dysdiadochokinesia

    • Dysmetria on finger-nose testing

    • Essential tremor

    • Gait ataxia

    • Present Romberg sign

    Correct Answer
    A. Gait ataxia
    Explanation
    Based on the information provided, the most likely finding on neurologic examination of the patient prior to his death would be gait ataxia. This is because the patient had a long history of alcoholism, which can lead to damage to the cerebellum. Gait ataxia is a common manifestation of cerebellar dysfunction, causing unsteady and uncoordinated movements while walking. The other options, such as dysdiadochokinesia, dysmetria, essential tremor, and Romberg sign, are not specifically associated with alcoholism or pneumonia.

    Rate this question:

  • 41. 

    An epidemiologist is investigating an outbreak of diarrhea among a total of 1000 consumers of vegetables. Of those consumers, 8OO people ate tomatoes and 200 people ate lettuce.  A total of 400 people became ill; 80 of these people ate tomatoes, and 40 people ate lettuce. Which of the following indicates the probability of diarrhea having developed in people who consumed lettuce?

    • 0.08

    • 0.1

    • 0.2

    • 0.4

    • 0.5

    Correct Answer
    A. 0.2
    Explanation
    The probability of diarrhea having developed in people who consumed lettuce is 0.2. This is determined by taking the number of people who ate lettuce and became ill (40) and dividing it by the total number of people who ate lettuce (200).

    Rate this question:

  • 42. 

    A 30-year-old woman is brought to the emergency department 6 hours after the onset of severe abdominal pain and confusion. Her brother, father, and paternal grandmother had similar problems. Two weeks ago, she began a low-calorie diet. Her pulse is 120/rnin, and blood pressure is 1601110 mm Hg. Physical examination shows restlessness, excess sweating, and tremors. There is no abdominal tenderness. Urine studies show an increased porphobilinogen concentration. Which of the following is the most likely pattern of inheritance causing this patient's condition?

    • Autosomal dominant

    • Autosomal recessive

    • Mitochondrial DNA mutation

    • Mutifactorial

    • X-linked dominant

    • X-linked recessive

    Correct Answer
    A. Autosomal dominant
    Explanation
    The patient's condition is most likely caused by autosomal dominant inheritance because her brother, father, and paternal grandmother also had similar problems. Autosomal dominant inheritance means that only one copy of the mutated gene is needed to inherit the condition.

    Rate this question:

  • 43. 

    A 54-year-old man has a squamous cell carcinoma of the right lung. Analysis of his germline DNA shows two alleles, m and n, at the microsatellite locus Z tightly linked to the p53 gene. Similar analysis of the neoplastic cells shows the presence of the m allele only. These findings are most likely due to which of the following processes?

    • Gemiline mosaicisrn

    • Loss of heterozygosity

    • P53 Gene amplification

    • Pericentric inversion involving p53 and locus Z

    • Point Mutation of allele n

    Correct Answer
    A. Loss of heterozygosity
    Explanation
    Loss of heterozygosity is the most likely explanation for the findings described. Loss of heterozygosity occurs when one allele is lost or inactivated in a tumor, resulting in the presence of only one allele. In this case, the analysis of the neoplastic cells shows the presence of only the m allele, indicating that the n allele has been lost. This loss of heterozygosity could be a result of a genetic event such as a deletion or mutation that specifically affects the n allele in the tumor cells.

    Rate this question:

  • 44. 

    A 60-year-old man comes to the physician because of a 2-year history of progressive shortness of breath with exertion. His two younger siblings have had similar symptoms. His mother died of dilated cardiomyopathy. Physical examination shows jugular venous distention and ankle edema. There is hepatomegaly. Inspiratory crackles are heard over both lung bases. A chest x-ray shows cardiomegaly and pulmonary congestion; angiography confirms dilated cardiomyopathy.  An atrial endocardial biopsy specimen shows abnormal sarcomeres with paracrystalline inclusions in mitochondria. Sequencing of mitochondria! DNA shows a G-to-A transition. This results in an added A:T base pair to the 3' end of the tRNA, thus shortening the C loop. Which of the following is the most likely effect of this mutation on mitochondrial function?         

    • Decreased mRNA stability

    • Decreased protein synthesis

    • Decreased replication

    • Increased mRNA stability

    • Increased protein synthesis

    • Increased replication

    Correct Answer
    A. Decreased protein synthesis
    Explanation
    The G-to-A transition in the mitochondrial DNA results in an added A:T base pair to the 3' end of the tRNA, which shortens the C loop. This mutation is most likely to affect mitochondrial function by causing decreased protein synthesis. tRNA molecules play a crucial role in protein synthesis by carrying amino acids to the ribosome. Any mutation in the tRNA can disrupt this process and lead to decreased protein synthesis. This can further contribute to the development of dilated cardiomyopathy, as proteins are essential for proper cardiac function.

    Rate this question:

  • 45. 

    An investigator is studying  B2-adrenoreceptors in female experimental animals. During the experiment, epinephrine is injected intramuscularly into each animal, and the effects on B2- adrenoreceptors are then observed. Which of the following physiologic effects is most likely to be observed in these animals?

    • Increased myocardial contractility

    • Internal urethral sphincter contraction

    • Lipolysis

    • Pilomotor contraction

    • Papillary dilation

    • Uterine relaxation

    Correct Answer
    A. Uterine relaxation
    Explanation
    During the experiment, epinephrine is injected, which is a hormone that activates B2-adrenoreceptors. B2-adrenoreceptors are known to cause relaxation of smooth muscles, including the muscles in the uterus. Therefore, the most likely physiologic effect observed in these animals would be uterine relaxation. This is because epinephrine would activate the B2-adrenoreceptors in the uterus, leading to relaxation of the uterine muscles.

    Rate this question:

  • 46. 

    In order to determine risk factors for death from coronary artery disease (CAD), persons aged 30 years and older are studied in a community. Every 2 years for a total of 10 years, blood pressure, serum cholesterol concentration, and smoking status are assessed along with deaths from CAD. Persons with increased blood pressure are compared with those who have normal blood pressure to determine which group has greater mortality from coronary artery disease. Which of the following best describes this type of study?

    • Case-control study

    • Case series study

    • Cross-sectional study

    • Ecologic study

    • Observational cohort study

    • Randomized clinical trial

    Correct Answer
    A. Observational cohort study
    Explanation
    An observational cohort study is the best description for this type of study because it involves following a group of individuals over a period of time (10 years in this case) and collecting data on their blood pressure, serum cholesterol concentration, smoking status, and deaths from coronary artery disease. This type of study allows researchers to observe the relationship between the risk factors (increased blood pressure) and the outcome (mortality from coronary artery disease) without intervening or manipulating any variables.

    Rate this question:

  • 47. 

    An executor of an estate consults with a physician concerning the terms of a will. The deceased woman was a philanthropist who was active in addressing disparities in health care. She designated that a large sum of her money be used to educate the public about the leading cause of death in women. The most appropriate use of this money would be a program addressing which of the following diseases?

    • Breast cancer

    • Cardiovascular disease

    • Cerebral infarction

    • Cervical cancer

    • Ovarian cancer

    Correct Answer
    A. Cardiovascular disease
    Explanation
    The most appropriate use of the deceased woman's money would be a program addressing cardiovascular disease. This is because cardiovascular disease is the leading cause of death in women, and the woman's philanthropic efforts were focused on addressing disparities in healthcare. By educating the public about cardiovascular disease, the program can help raise awareness, promote prevention, and improve access to healthcare for women, aligning with the woman's intentions and goals.

    Rate this question:

  • 48. 
    A 46-year-old man receives the diagnosis of squamous cell carcinoma of the esophagus. A barium swallow is shown. Esophagectomy at the region indicated by the arrows is most likely to involve ligation of arterial branches of which of the following vessels? - ProProfs

    A 46-year-old man receives the diagnosis of squamous cell carcinoma of the esophagus. A barium swallow is shown. Esophagectomy at the region indicated by the arrows is most likely to involve ligation of arterial branches of which of the following vessels?

    • Aorta

    • Internal thoracic arteries

    • Pulmonary arteries

    • Superior mesenteric artery

    • Thyrocervical trunk

    Correct Answer
    A. Aorta
    Explanation
    In the case of squamous cell carcinoma of the esophagus, surgical removal of the affected portion of the esophagus (esophagectomy) is often necessary. The arrows on the barium swallow indicate the region where the esophagectomy is most likely to be performed. Since the esophagus is located posterior to the trachea and anterior to the vertebral column, the region indicated by the arrows is in close proximity to the aorta. Therefore, ligation of arterial branches of the aorta would be involved in this procedure.

    Rate this question:

  • 49. 

    A female newborn is delivered al 34 weeks gestation in an advanced-care setting where special delivery systems are available. The diagnosis of persistent pulmonary hypertension is made. Considering that the newborn can be carefully monitored for methemoglobinemia, which of the following is the most appropriate therapy?

    • Desflurane

    • Hyperbaric oxygen

    • Nitric oxide

    • Nitrous oxide

    • Oxygen diluted with helium

    Correct Answer
    A. Nitric oxide
    Explanation
    Nitric oxide is the most appropriate therapy for a newborn with persistent pulmonary hypertension. Nitric oxide is a selective pulmonary vasodilator that helps to relax the smooth muscles in the blood vessels of the lungs, improving oxygenation and reducing pulmonary hypertension. It is commonly used in neonatal intensive care units for this purpose. The other options, such as Desflurane, Hyperbaric oxygen, Nitrous oxide, and Oxygen diluted with helium, are not indicated for the treatment of persistent pulmonary hypertension in newborns.

    Rate this question:

Quiz Review Timeline (Updated): Mar 22, 2023 +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Mar 22, 2023
    Quiz Edited by
    ProProfs Editorial Team
  • Nov 15, 2012
    Quiz Created by
    Chachelly

Recent Quizzes

USMLE Full Length Exam 2 USMLE Full Length Exam 2
USMLE Full Length Exam 1 USMLE Full Length Exam 1
Histology - USMLE- Muscle tissue Histology - USMLE- Muscle tissue
USMLE : ICM and Pathology Questions! Trivia Quiz USMLE : ICM and Pathology Questions! Trivia Quiz
Block 13 USMLE Behavior and Pharm Block 13 USMLE Behavior and Pharm
Hardest Trivia Questions Quiz on USMLE Hardest Trivia Questions Quiz on USMLE
Back to Top Back to top
Advertisement
×

Wait!
Here's an interesting quiz for you.

We have other quizzes matching your interest.