NBME Or National Board Of Medical Examiners Trivia Quiz

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The long thoracic nerve innervates the serratus anterior muscle, which is responsible for stabilizing the scapula against the thoracic wall. Injury to the long thoracic nerve can result in winging of the scapula, as seen in this patient when she presses her outstretched arms against a wall. The other nerves listed do not innervate the serratus anterior muscle and would not cause this specific symptom.

The presentation of respiratory distress shortly after birth, along with cyanosis, lower rib retractions, and fine densities with a reticulogranular appearance on chest x-rays, suggests a diagnosis of pulmonary surfactant deficiency. Pulmonary surfactant is responsible for reducing surface tension in the alveoli, allowing for proper lung expansion and gas exchange. In premature infants, insufficient production or lack of surfactant can lead to respiratory distress syndrome (RDS). This condition is more common in premature infants, especially those born before 34 weeks gestation. Erythroblastosis fetalis, extralobar sequestration, intracranial hemorrhage, and situs inversus would not typically present with the same respiratory findings.

The patient's presentation of severe headache, confusion, nuchal rigidity, and the worst headache he has ever had is highly suggestive of subarachnoid hemorrhage. Subarachnoid hemorrhage occurs when there is bleeding into the subarachnoid space, often due to rupture of an intracranial aneurysm. The presence of nuchal rigidity indicates meningeal irritation, which is a common finding in subarachnoid hemorrhage. A CT scan without contrast is the initial imaging modality of choice for suspected subarachnoid hemorrhage, and it may show evidence of blood in the subarachnoid space.

Based on the given symptoms and findings, the most likely diagnosis is a leaking aortic aneurysm. The patient's presentation of sudden onset weakness, nausea, abdominal and back pain that radiates to the lower extremities, along with pale appearance, cold sweat, weak pulses in the lower extremities, and a faint bruit in the lower abdomen, are consistent with a ruptured or leaking abdominal aortic aneurysm. This is a life-threatening condition that requires immediate medical intervention. Acute compression fracture of the L-3 vertebral body, herniated L-3 to L-4 intervertebral disc, perforated rectum, and perforated sigmoid colon do not explain the full range of symptoms and findings seen in this patient.

The patient's presentation of severe back pain, weight loss, and point tenderness over the L4-5 area, along with the presence of 4+ proteins in the urine, is highly suggestive of multiple myeloma. Multiple myeloma is a malignancy of plasma cells that commonly presents with bone pain, hypercalcemia, renal failure, and anemia. The photomicrograph of findings from bone marrow aspiration would likely show an increase in abnormal plasma cells, confirming the diagnosis. Hyperparathyroidism, metastatic bone disease, Paget disease, and Waldenstrom macroglobulinemia do not typically present with the same constellation of symptoms and findings as seen in this patient.

Cluster headaches: recurrent brief attacks of sudden severe unilateral peri-orbital pain. Can occur unexpectedly, often at a specific time of day/year, particularly during sleep. Causes excruciating pain behind the eyes. Idiopathic

The correct answer is ubiquitination. Ubiquitination is a post-translational modification process in which ubiquitin molecules are attached to proteins. This modification targets the proteins for degradation by the proteasome. In this patient with cystic fibrosis, there is a mutation in the cystic fibrosis transmembrane conductance regulator gene, leading to misfolded proteins. These misfolded proteins need to be destroyed, and this is achieved through ubiquitination followed by proteasomal degradation. Dimerization, glycosylation, phosphorylation, and sulfation are not directly involved in the degradation of misfolded proteins.

Mechanism of the antibacterial effect
- It is due mainly to the two following actions:
1) Beta-lactam antibiotics bind to specific beta-lactam receptors called penicillin-binding proteins (PBPs) located on the cytoplasmic membrane. These proteins are enzymes endowed with various catalytic functions which are inhibited by the binding with the
antibiotic. The most important enzymes inhibited are transpeptidases which catalyze the
final cross-link step in the synthesis of murein (also called peptidoglycan ). Since peptidoglycan layers are constituents of bacteria cell wall, the ***synthesis of this wall is blocked.***
2) Autolytic enzymes (called autolysins or murein hydrolases) are present in the cell wall and degrade the peptidoglycan. Beta-lactam antibiotics can activate these autolysins (apparently by blocking an autolysin inhibitor) so promoting the lysis of bacteria.

The presence of cuboidal epithelial cells with electron dense lamellar bodies in the alveoli suggests that these cells are producing surfactant. Surfactant is a substance that reduces surface tension in the alveoli, preventing them from collapsing and facilitating gas exchange. This is important for maintaining proper lung function. The other options, such as collagen, type I, epinephrine, histamine, and IgG, are not associated with the production of surfactant.

This question is the most appropriate because it allows the patient to express their feelings and experiences with self-administering insulin. It opens up a conversation about any difficulties or challenges the patient may be facing, without making assumptions or placing blame. This approach promotes open communication and understanding between the physician and the patient, which can help identify any barriers to insulin administration and find appropriate solutions.

This man is most likely to have sinusitis because the scenario suggests that the man has Kartagener syndrome, a condition characterized by immotile cilia. Kartagener syndrome is associated with primary ciliary dyskinesia, which can lead to chronic respiratory infections such as sinusitis. The other conditions listed are not typically associated with immotile cilia or infertility.

Imprinting is the best genetic principle that explains the findings in this family. Imprinting refers to the differential expression of a gene depending on whether it is inherited from the mother or the father. In this case, the balanced translocation involving chromosome 15q11-q13 is likely disrupting the expression of imprinted genes in this region. This disruption leads to the clinical features observed in the affected individuals, such as almond-shaped eyes, mental retardation, and hyperphagia. The fact that both the father and paternal aunt have the same balanced translocation suggests that the translocation is inherited in an imprinted manner.

The patient's history of alcohol consumption and physical examination findings suggest that he has liver cirrhosis. Liver cirrhosis can lead to a decrease in testosterone production, which can cause erectile dysfunction. Testosterone is the primary male sex hormone responsible for maintaining sexual function. Therefore, decreased serum concentrations of testosterone are the most likely cause of this patient's erectile dysfunction.

This is Bullous pemphigoid

The patient's presentation of amenorrhea, blue-tinged vaginal mucosa, and soft uterus suggests a diagnosis of Asherman syndrome, which is characterized by intrauterine adhesions that result in menstrual abnormalities. The most appropriate next step to establish the diagnosis is to measure urine B-human chorionic gonadotropin (hCG) concentration. This is because Asherman syndrome can cause a false-negative pregnancy test due to the inability of the endometrium to respond to hCG. Therefore, measuring urine hCG can help rule out pregnancy as a cause of the patient's amenorrhea and further support the diagnosis of Asherman syndrome.

The most likely diagnosis in this case is diverticulitis. Diverticulitis is characterized by inflammation and infection of the diverticula, which are small pouches that can form in the colon. The patient's symptoms of abdominal pain, diarrhea, and loss of appetite, along with the physical examination findings of distention and rebound tenderness localized to the left lower quadrant, are consistent with diverticulitis. The presence of a thickened colonic wall and pericolic fat inflammation on the abdominal CT scan further support this diagnosis.

The correct answer is IgM. IgM is the first antibody isotype produced during an immune response and is involved in the primary immune response. In this case, the mother received a vaccine and generated an antibody response to the polysaccharide antigen within 1 month. The presence of IgM in her serum prior to labor suggests that she produced IgM antibodies in response to the vaccine. IgM antibodies are typically produced early in an immune response and are involved in neutralizing pathogens and activating the complement system.

The patient's symptoms of sudden onset right-sided chest pain and shortness of breath, which worsens with inspiration, along with a clear lung auscultation, are suggestive of a pulmonary embolism. In a ventilation-perfusion lung scan, a pulmonary embolism would present as an absence of perfusion in some areas that are ventilated. This occurs because the blood flow to those areas is blocked by a clot, leading to a ventilation-perfusion mismatch. This finding is consistent with the patient's symptoms and clinical presentation.

The histologic findings of small shrunken hepatocytes with intense eosinophilic cytoplasm, fragmented nuclear chromatin, and cytoplasmic bleb formations suggest apoptosis. Apoptosis is a programmed cell death that occurs in response to various stimuli, such as infection or injury. It is characterized by cell shrinkage, chromatin condensation, and the formation of apoptotic bodies. In this case, the patient's symptoms of fever, headache, chills, and pain in the upper right quadrant of the abdomen may be indicative of an underlying infection or inflammation, which could trigger apoptosis in the liver cells.

The patient's presentation of bloody diarrhea and diffuse abdominal pain, along with the findings of patchy ulceration on colonoscopy, is consistent with the diagnosis of ischemic colitis. Ischemic colitis occurs when there is a decrease in blood flow to the colon, leading to inflammation and ulceration. This can be caused by various factors, such as atherosclerosis, emboli, or low blood pressure. Given the patient's age and history of cerebral infarction, it is plausible that she may have vascular disease that has affected the blood supply to her colon, resulting in ischemic colitis.

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This patient presents with symptoms of anemia, including fatigue and pallor, and has laboratory findings consistent with anemia, such as low hemoglobin and hematocrit levels. The most appropriate pharmacotherapy for this patient is erythropoietin, which is a hormone that stimulates the production of red blood cells. Erythropoietin can be used to treat anemia in patients with chronic kidney disease, which is likely the cause of this patient's anemia given his elevated urea nitrogen and creatinine levels.

Homologous pairing of chromosomes in prophase I is essential for crossing over. During crossing over, homologous chromosomes exchange genetic material, resulting in genetic recombination. This process increases genetic diversity and ensures the proper segregation of chromosomes during meiosis. Centromere division, chromosome uncoiling, and DNA replication are not directly dependent on homologous pairing and crossing over.

The patient's symptoms of behavioral changes, failing classes, staying out late, increased pulse and blood pressure, pupillary dilation, diaphoresis, agitated affect, and confused thought process are consistent with intoxication with amphetamines. Amphetamines are stimulant drugs that can cause increased energy, euphoria, and hyperactivity. They can also lead to impaired judgment, confusion, and agitation. The patient's exposure to a new neighborhood with drug-addicted and criminal teenagers suggests a potential source of amphetamine use.

The Musculocutaneous Nerve (C5-C7) innervates the flexors in the arm- the biceps brachii, brachialis, and Coracobrachialis. It then travels to the lateral forearm where it provides cutaneous innervation.

The patient presented with acute kidney injury (AKI) following a significant blood loss due to a bleeding duodenal ulcer. The laboratory findings, including elevated urea nitrogen and creatinine levels, along with the presence of granular casts in the urine sediment, indicate acute tubular necrosis (ATN) as the cause of AKI. The subsequent improvement in renal function, as indicated by clear urine sediment and normal renal function two weeks later, suggests regeneration of the tubular epithelial cells. Therefore, the histologic examination of a renal biopsy specimen at this time is most likely to show regenerating tubular epithelial cells.

The patient's presentation of bronze-colored skin, hepatosplenomegaly, and increased iron concentration in a liver biopsy specimen is consistent with hemochromatosis. Hemochromatosis is a genetic disorder characterized by increased intestinal iron absorption, leading to iron overload in the body. The increased iron absorption results in iron deposition in various organs, including the liver, causing cirrhosis. The elevated ferritin levels and transferrin saturation also support the diagnosis of hemochromatosis. The patient's family history of cirrhosis and type 2 diabetes mellitus further suggests a hereditary form of hemochromatosis.

Cisplatin crosslinks DNA in several different ways, interfering with cell division by mitosis. The damaged DNA elicits DNA repair mechanisms, which in turn activate apoptosis when repair proves impossible (from Wikipedia)

Clomiphene is a SERM that an Estrogen receptor antagonist in the hypothalamus, which stops negative feedback, and increases GnRH => increase LH, FSH => jumpstarting ovulation

Loss of negative glomerular charge is the most likely cause of this patient's condition. The presence of puffy eyes and proteinuria (3+protein on urine dipstick test) suggests that there is an issue with the filtration process in the kidneys. The negative charge on the glomerular basement membrane normally repels negatively charged proteins, preventing them from being filtered into the urine. However, in this case, the negative charge is lost, allowing proteins to pass through and be excreted in the urine. This is known as loss of negative glomerular charge and is commonly seen in conditions such as nephrotic syndrome.

After undergoing a radical mastectomy with removal of the axillary lymph nodes, the woman is experiencing painful edema in her left upper extremity. This is likely due to lymphedema, which occurs when lymphatic drainage is impaired. The most effective therapy for decreasing swelling in this patient is the use of a compression sleeve. Compression therapy helps to improve lymphatic flow and reduce fluid accumulation. Applying heat, diuretic therapy, exercise therapy, and passive movement may have some benefits, but they are not as effective as a compression sleeve in managing lymphedema.

Promoting thorough hand cleansing before and after medical personnel visit each patient is the most likely infection control measure to decrease the spread of the highly resistant strain of Klebiella pneumonia. Hand hygiene is a crucial aspect of infection control and can effectively prevent the transmission of pathogens. By ensuring that medical personnel properly clean their hands before and after visiting each patient, the risk of spreading the organism to other patients in the ICU and elsewhere in the hospital can be significantly reduced.

Activation of hepatic adenylyl cyclase leads to increased levels of cyclic adenosine monophosphate (cAMP) in the liver. This activates protein kinase A (PKA), which in turn phosphorylates and activates hepatic glycogen phosphorylase. Activated glycogen phosphorylase breaks down glycogen into glucose, leading to an increase in blood glucose concentration. Therefore, activation of hepatic adenylyl cyclase is the most likely cause of this patient's hyperglycemia.

The strongest predisposing risk factor for this patient's condition is diet. The patient's history of unintentional weight loss and epigastric abdominal pain, along with the finding of a gastric ulcer confirmed to be adenocarcinoma, suggests the presence of gastric cancer. Diet plays a significant role in the development of gastric cancer, and the patient's traditional Japanese diet may be a contributing factor. Certain dietary factors, such as high salt intake, low fruit and vegetable consumption, and the consumption of smoked or pickled foods, have been associated with an increased risk of gastric cancer.

The given sampling technique is population-based because the study sample is selected based on census data, which is representative of the national census data for the factors selected. This means that the sample is chosen in a way that accurately reflects the characteristics of the population being studied, in this case, African American men and women in the USA.

The most likely cause of the increased muscle weakness in this patient is desensitization of nicotinic receptors. Myasthenia gravis is an autoimmune disorder characterized by the production of antibodies against nicotinic acetylcholine receptors at the neuromuscular junction. Neostigmine, a cholinesterase inhibitor, is commonly used to treat myasthenia gravis by increasing the availability of acetylcholine at the neuromuscular junction. However, long-term use of neostigmine can lead to desensitization of the nicotinic receptors, resulting in decreased responsiveness to acetylcholine and worsening muscle weakness.

The most likely explanation for the persistent colonization of this patient by the organism is biofilm formation in the lower respiratory tract. Biofilm is a protective layer formed by bacteria that allows them to adhere to surfaces and resist eradication by antibiotics. In cystic fibrosis patients, the thick mucus in the airways provides an ideal environment for biofilm formation. This biofilm protects the bacteria from antibiotics and the immune system, leading to chronic infections.

The correct answer is "Induction of cytochrome P450." Alcohol is known to induce cytochrome P450 enzymes in the liver, leading to increased metabolism of drugs and toxins. This can result in increased production of toxic metabolites, such as N-acetyl-p-benzoquinonelmine, which can cause liver damage. In this case, the patient's symptoms of nausea, vomiting, and lethargy, along with the increased hepatic aminotransferase levels, are consistent with alcohol-induced liver injury.

Praziquantel is the correct answer because it is known to increase the permeability of cell membranes to calcium, leading to paralysis and death of parasites. This aligns with the results of the experiment described in the question. Albendazole, Bithionol, Diethylcarbamazine, and Niclosamide do not have the same mechanism of action as Drug X and therefore are not the most closely resembling option.

The most likely cause of the decrease in calf circumference is increased protein degradation. This is because the patient had a ruptured Achilles tendon which required surgical repair and immobilization. Immobilization can lead to muscle atrophy and loss of muscle mass. Increased protein degradation is a key mechanism in muscle wasting and atrophy. Therefore, it is the most likely cause of the decrease in calf circumference.

The pulmonary circulation is responsible for oxygenating the blood and removing carbon dioxide, while the bronchial circulation supplies blood to the conducting airways of the lungs. Since the pulmonary circulation is directly involved in gas exchange, it is expected to have a larger percentage of cardiac output compared to the bronchial circulation. This is because a larger amount of blood needs to be oxygenated and circulated to the lungs for gas exchange to occur. Therefore, the correct answer is that the pulmonary circulation has a larger percentage of cardiac output.

The presence of a 5-cm, rounded mass next to the bifurcation of the carotid artery, positive immunohistochemistry for synaptophysin, chromogranin, and neuron-specific enolase, and numerous electron-dense, membrane-bound neurosecretory granules seen on electron microscopy are all characteristic findings of a paraganglioma. Paragangliomas are neuroendocrine tumors that arise from the paraganglia, which are clusters of neuroendocrine cells located along the autonomic nervous system. They can occur in various locations, including the head and neck, and are often positive for neuroendocrine markers. In this case, the presence of the mass in the neck and the positive immunohistochemistry and electron microscopy findings support the diagnosis of a paraganglioma.

The most appropriate interpretation of the finding is that selenium is associated with a lower risk of gastric cancer. This is supported by the relative risk estimate of 0.3, which is less than 1. A relative risk less than 1 indicates a lower risk of the outcome (gastric cancer) in individuals with a high-selenium diet compared to those without. Additionally, the confidence interval of 0.1-0.8 suggests that the true relative risk falls within this range with 95% certainty. Therefore, it can be concluded that selenium is associated with a lower risk of gastric cancer.

This patient's recurrent yeast infections and deficiency of myeloperoxidase suggest a defect in the production of hydroxyl-halide radicals. Myeloperoxidase is an enzyme that catalyzes the production of hydroxyl-halide radicals, which are important for the killing of microorganisms by neutrophils. Without the production of these radicals, the patient's neutrophils would have impaired ability to kill microorganisms, leading to increased susceptibility to infections. Decreased oxygen consumption after phagocytosis, defective neutrophil degranulation, defective production of prostaglandins, and inability to produce hydrogen peroxide are not directly related to the production of hydroxyl-halide radicals and are therefore less likely to be the cause of the patient's increased susceptibility to infections.

The correct answer is E. Based on the given information, the amount of calcium sequestration in the sarcoplasmic reticulum is highest during response E. This can be inferred because response E shows the strongest contractile response to electrical stimulation. Since calcium is essential for muscle contraction, the higher the contractile response, the higher the amount of calcium sequestration in the sarcoplasmic reticulum.

The patient's symptoms, including weakness, numbness, and areflexia, along with the electrophysiologic findings of slow conduction velocity in multiple nerves, suggest a peripheral neuropathy. The decreased sensation to vibration and joint position indicates impaired proprioception, which is mediated by the dorsal columns of the spinal cord. Voltage-gated Ca+ + channels are responsible for the entry of calcium ions into the presynaptic terminal, triggering the release of neurotransmitters, including glutamate, which is essential for normal synaptic transmission in the dorsal columns. Impaired function of these channels could lead to the observed symptoms and electrophysiologic findings.