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Question 1
Incorrect
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You are studying the measurement of a new biomarker for cognitive decline, and how it might be applied to geriatric care. You assume that the data for this particular biomarker are likely to be normally distributed.
When considering the normal distribution, which of the following is true?Your Answer: 95% of observations lie within the mean and 1 standard deviation
Correct Answer: The mean, median and mode are the same value
Explanation:Normal Distribution and Parametric Tests
Normal distribution is a bell-shaped curve that is symmetrical on both sides. The mean, median, and mode of a normal distribution are equal. The probability that a normally distributed random variable lies between (mean – 1.96 standard deviation) and (mean + 1.96 standard deviation) is 0.95, while the probability that it lies between (mean – standard deviation) and (mean + standard deviation) is 0.68. Additionally, 95% of the distribution of sample means lie within 1.96 standard deviations of the population mean.
Parametric tests are statistical tests that assume the data are normally distributed. However, data that are not normally distributed can still be subject to a parametric test, but they need to be transformed first. It is important to understand normal distribution and parametric tests in order to accurately analyze and interpret data.
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This question is part of the following fields:
- Clinical Sciences
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Question 2
Incorrect
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Which nerve provides the motor supply to the brachialis muscle?
Your Answer: Median and musculocutaneous nerve
Correct Answer: Radial and musculocutaneous nerve
Explanation:The Brachialis Muscle: Anatomy and Innervation
The brachialis muscle is responsible for flexing the forearm and is located in the anterior half of the humerus and intermuscular septa. It attaches to the coronoid process and tuberosity of the ulna at the elbow joint. The main nerve supply for the brachialis muscle is the musculocutaneous nerve, with C6 and radial nerve also playing a role. Additionally, the lateral part of the brachialis muscle is supplied by branches from the C7 root. Overall, the brachialis muscle is an important muscle for forearm flexion and is innervated by multiple nerves.
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This question is part of the following fields:
- Clinical Sciences
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Question 3
Correct
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Which type of cell is found in the hepatic space of Disse?
Your Answer: Stellate cells
Explanation:The Cell Types in the Liver
The liver is composed of different types of cells that perform various functions. The main epithelial cell type in the liver is the hepatocyte, which is arranged in plates and flanked by sinusoids. The sinusoids are lined by endothelial cells, and there is a small space between the endothelial cells and hepatocytes called the space of Disse. Stellate cells, also known as Ito cells, are found in this space. They store vitamin A when inactive, but when inflammation occurs, they become activated and secrete cytokines and extracellular matrix, which contribute to hepatic fibrosis. Macrophages, known as Kupffer cells, are located within the lumen of the hepatic sinusoids. On the other hand, cholangiocytes are the epithelial cells that line the bile ducts, but not the bile canaliculi, which are made from the lateral walls of hepatocytes. the different cell types in the liver is crucial in diagnosing and treating liver diseases.
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This question is part of the following fields:
- Clinical Sciences
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Question 4
Incorrect
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Which organ is in direct contact with the left kidney's anterior surface without being separated by peritoneum?
Your Answer: Spleen
Correct Answer: Pancreas
Explanation:Retroperitoneal Structures in Proximity to the Left Kidney
The retroperitoneal structures that are in direct contact with the anterior surface of the left kidney include the pancreas, adrenal gland, and colon. While the pancreas is the only structure commonly listed as retroperitoneal, it is important to note that the adrenal gland and colon also share this classification and are located in close proximity to the left kidney.
According to Gray’s Anatomy of the Human Body, which focuses on the urinary organs, the location and relationship of these structures is important for medical professionals. By knowing the retroperitoneal structures in proximity to the left kidney, doctors can better diagnose and treat conditions that may affect these organs.
In summary, while the pancreas is commonly listed as the only retroperitoneal structure in contact with the left kidney, it is important to also consider the adrenal gland and colon in this classification. the location and relationship of these structures is crucial for medical professionals in providing effective care for their patients.
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This question is part of the following fields:
- Clinical Sciences
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Question 5
Correct
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While taking a patient's medical history, you discover that there is a significant family history of a particular disease. Diseases that are inherited in an autosomal dominant manner typically manifest in early adulthood due to structural gene abnormalities, with both males and females being affected equally. Which of the following diseases does not follow an autosomal dominant inheritance pattern?
Your Answer: Haemochromatosis
Explanation:Abnormal Binding Proteins Resulting in Iron Deposition and Multiple Organ Dysfunction
Iron deposition due to an abnormality in binding proteins can lead to various health complications. This condition is characterized by the deposition of iron in different organs, including the heart, liver, pancreas, and skin. The abnormality in binding proteins results in the accumulation of iron in these organs, leading to cardiomyopathy, cirrhosis, pancreatic failure, and skin pigmentation.
This condition is inherited in an autosomal recessive pattern, meaning that an individual must inherit two copies of the mutated gene, one from each parent, to develop the condition. The recessive form of this condition is also known as infantile polycystic kidney disease, which predominantly affects children.
Overall, iron deposition due to an abnormality in binding proteins can cause multiple organ dysfunction and can be inherited in an autosomal recessive pattern. Early diagnosis and management of this condition are crucial to prevent further complications and improve the quality of life of affected individuals.
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This question is part of the following fields:
- Clinical Sciences
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Question 6
Correct
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Which of the following is a function that the liver does not perform?
Your Answer: Synthesis of immunoglobulins
Explanation:Functions of the Liver in Regulating Blood Composition
The liver plays a crucial role in regulating the composition of blood to maintain appropriate levels of solutes, toxins, and drugs. It achieves this through various metabolic reactions, including removing excess solutes, synthesizing deficient solutes, and storing solutes for later use. One of the liver’s essential functions is to maintain blood glucose levels by storing excess glucose as glycogen after a meal and releasing it back into the bloodstream as glucose during fasting. Additionally, the liver can produce glucose through gluconeogenesis using other substances such as fat, protein, or other sugars.
The liver also processes nitrogenous waste from protein catabolism by converting ammonium from amino acids to urea, which is less toxic and can be excreted by the kidneys. Another critical function of the liver is producing bilirubin from haem in red blood cells, which is then processed to make bile exclusively in the liver. The liver also produces various plasma proteins, including albumin, hormones, cytokines, and C-reactive protein, but not immunoglobulins, which are made by plasma cells. Overall, the liver’s functions are vital in maintaining the body’s homeostasis and ensuring proper blood composition.
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This question is part of the following fields:
- Clinical Sciences
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Question 7
Incorrect
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Which substance is not typically found in bile?
Your Answer: Cholic acid
Correct Answer: Glucose
Explanation:The Role and Composition of Bile
Bile plays a crucial role in the excretion of substances that are not easily eliminated by the kidneys, particularly lipid-rich molecules and non-polar substances. Its main components include bile acids or bile salts, cholesterol, phospholipids (such as lecithin), conjugated bilirubin, electrolytes, and a small amount of protein. Glucose is not typically found in bile as it is highly soluble and can be excreted in urine if present in excess in the bloodstream.
Cholesterol is broken down into bile acids, specifically cholic acid and chenodeoxycholic acid, which are then conjugated with proteins like glycine or taurine to form bile salts. Conjugated bilirubin, on the other hand, is a byproduct of the breakdown of haem from haemoglobin and myoglobin. Overall, bile serves as an important mechanism for the elimination of certain substances from the body.
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This question is part of the following fields:
- Clinical Sciences
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Question 8
Incorrect
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To evaluate the effectiveness of a home cholesterol testing kit, a group of 500 individuals under the age of 40 were recruited. Each participant provided a blood sample for analysis. The results showed that 480 individuals had normal cholesterol levels and 20 individuals had high cholesterol levels. What is the sensitivity of the test?
Your Answer: 100%
Correct Answer: 98%
Explanation:Specificity in Medical Testing
Specificity is a crucial concept in medical testing that refers to the accuracy of a test in identifying individuals who do not have a particular condition. In simpler terms, it measures the proportion of people who are correctly identified as not having the condition by the test. For instance, if a test has a specificity of 98%, it means that 98 out of 100 people who do not have the condition will be correctly identified as negative by the test.
To calculate specificity, we use the formula: Specificity = True Negative / (False Positive + True Negative). This means that we divide the number of true negatives (people who do not have the condition and are correctly identified as negative) by the sum of false positives (people who do not have the condition but are incorrectly identified as positive) and true negatives.
It is important to note that highly specific tests are useful for ruling conditions in, which means that if the test is positive, the person is very likely to have the disease. However, it is rare to find tests with 100% sensitivity and/or specificity, including pregnancy tests. Therefore, it is crucial to interpret test results in conjunction with other clinical information and to consult with a healthcare professional for proper diagnosis and treatment.
In summary, specificity is essential in medical testing as it helps to determine the accuracy of a test in identifying individuals who do not have a particular condition. By using the formula and interpreting test results in conjunction with other clinical information, healthcare professionals can make informed decisions about diagnosis and treatment.
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This question is part of the following fields:
- Clinical Sciences
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Question 9
Correct
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A 25-year-old individual is undergoing testing for asthma. Prior to administering bronchodilators, their FEV1/FVC ratio is measured at 0.85, with the FVC at 90% of normal. What does this indicate?
Your Answer: Normal exam
Explanation:The FEV1/FVC ratio is a measure used in lung function tests to assess the health of the lungs. In normal individuals, this ratio ranges from 0.75 to 0.85. If the ratio falls below 0.70, it suggests an obstructive problem that reduces the volume of air that can be expelled in one second (FEV1). However, in restrictive lung disease, the FVC is also reduced, which can result in a normal or high FEV1/FVC ratio.
It is important to understand the FEV1/FVC ratio as it can help diagnose and monitor lung diseases such as chronic obstructive pulmonary disease (COPD) and asthma. A low ratio indicates that the airways are obstructed, while a normal or high ratio suggests a restrictive lung disease. Lung function tests are often used to assess the severity of these conditions and to monitor the effectiveness of treatment. By the FEV1/FVC ratio, healthcare professionals can provide appropriate care and management for patients with lung diseases.
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This question is part of the following fields:
- Clinical Sciences
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Question 10
Correct
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A 15-year-old girl is brought to the clinic by her mother due to complaints of severe abdominal cramps and heavy menstrual bleeding.
Which term accurately describes an excessive amount of menstrual bleeding?Your Answer: Menorrhagia
Explanation:Menstrual Disorders
Menstrual disorders are common among women and can cause discomfort and inconvenience. Menorrhagia is a condition where women experience prolonged and heavy periods at regular intervals. On the other hand, metrorrhagia, also known as spotting, is characterized by vaginal bleeding that is not in line with a regular menstrual cycle. Cryptomenorrhoea is a condition where menstruation occurs but is concealed, such as in the case of an imperforate hymen. Dysmenorrhoea, which often coexists with menorrhagia, refers to severe uterine pain experienced by some women during and around the time of menstruation.
Oligomenorrhoea, on the other hand, is a condition where menstrual bleeding occurs infrequently, with periods of non-menstruation for more than 35 days. When menstruation does not occur at all, this is called amenorrhoea. It is important for women to be aware of these conditions and seek medical attention if they experience any abnormal menstrual symptoms. Proper diagnosis and treatment can help manage these conditions and improve the quality of life for women.
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This question is part of the following fields:
- Clinical Sciences
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Question 11
Correct
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A 4-year-old girl is rushed to the emergency department by her father due to breathing difficulties. He suspects that she may have ingested a small toy while he was not looking.
Which of the following statements accurately describes the lower respiratory tract?Your Answer: The right main bronchus is more vertical than the left
Explanation:Anatomy of the Bronchial Tree
The trachea divides into two bronchi at the sternal angle, with the right bronchus being wider, shorter, and more vertical than the left. This anatomical difference makes it more likely for foreign objects to become lodged in the right bronchus. However, this difference only occurs after the age of one, so younger children are at equal risk for foreign body aspiration in either bronchus.
Each main bronchus further divides into lobar bronchi, with the left having two and the right having three. These lobar bronchi then give rise to tertiary or segmental bronchi, which supply a specific bronchopulmonary segment. These segments are anatomically and functionally separate from each other and can be removed without affecting the surrounding lung tissue.
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This question is part of the following fields:
- Clinical Sciences
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Question 12
Correct
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What is a common clinical feature that is linked to hypovolemia?
Your Answer: Dry mucous membranes
Explanation:Hypovolaemia
Hypovolaemia is a condition that occurs when there is a decrease in the volume of blood in the body. This can be caused by severe dehydration, poor oral fluid intake, excessive fluid losses in diarrhoea or through stomas, and major haemorrhage. The symptoms of hypovolaemia include dry mucous membranes, normal or increased sodium concentration in the blood, reduced jugular venous pressure, reduced urinary flow rate, and increased respiratory rate.
Dry mucous membranes are not a highly discriminating feature of hypovolaemia. The effect of hypovolaemia on sodium concentrations is highly variable. If hypovolaemia results from the loss of blood or fluid containing isotonic amounts of sodium, the sodium concentration is likely to stay within the reference range. However, if hypovolaemia is due to prolonged poor oral intake, hypernatraemia can result. Hypovolaemia alone is generally not associated with hyponatraemia unless there is concomitant infection, inflammation, or loss of sodium-rich fluids, for example, from a high-output stoma.
Reduced jugular venous pressure is a common symptom of hypovolaemia. The low circulating volume will cause a low JVP. In normal circumstances, the body responds to hypovolaemia by reducing urinary flow rates. If circulation is impaired by loss of blood, a common response is an increase in the respiratory rate. This is often an early feature of significant blood loss. the symptoms of hypovolaemia is important for prompt diagnosis and treatment.
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This question is part of the following fields:
- Clinical Sciences
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Question 13
Correct
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You are asked to see a 4-year-old girl with severe chronic malnutrition.
You are concerned about kwashiorkor.
What clinical feature is typical in cases of kwashiorkor?Your Answer: Abdominal swelling
Explanation:Protein-Energy Malnutrition
Protein-energy malnutrition (PEM) or protein energy undernutrition (PEU) occurs when the body’s intake of energy and protein is insufficient to meet its requirements. This can happen due to inadequate intake or an increase in requirements without a corresponding increase in intake. The result is a range of health problems, including undernutrition, which is sadly common in many parts of the world.
Undernutrition can take different forms, including kwashiorkor and marasmus. Kwashiorkor is characterized by inadequate protein intake, leading to oedema, abdominal swelling, and fat accumulation in the liver. Marasmus, on the other hand, involves inadequate consumption of both energy and protein, resulting in emaciation without oedema or abdominal swelling. The term ‘protein-energy undernutrition’ encompasses both of these scenarios.
It’s worth noting that malnutrition can refer to both overnutrition (obesity) and undernutrition, both of which have negative effects on the body’s health. However, in common usage, malnutrition typically refers to undernutrition. Additionally, malnutrition can also result from isolated deficiencies in vitamins or minerals. Overall, protein-energy malnutrition is crucial for promoting and preserving good health.
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This question is part of the following fields:
- Clinical Sciences
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Question 14
Incorrect
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Which tumour suppressor gene experiences loss of function as a late event in the multistep development model of colorectal carcinogenesis?
Your Answer: APC
Correct Answer: p53
Explanation:The Role of Tumor Suppressor Genes and Oncogenes in Colorectal Cancer
Colorectal cancer is a type of cancer that develops through a series of changes in the epithelium, known as the adenoma-carcinoma sequence. This process involves the accumulation of mutations in tumor suppressor genes and oncogenes. One of the most important tumor suppressor genes is p53, which is activated by cellular damage and oncogene activation. When activated, p53 inhibits cell growth and induces senescence or apoptosis. However, loss of functional p53 is a late event in colorectal carcinogenesis.
Another important tumor suppressor gene involved in the beta-catenin pathway is APC. It is mutated relatively early in the formation of colorectal cancers and is involved in regulating cell growth. On the other hand, Bcl-2 is an oncogene that promotes cell survival by inhibiting apoptosis. It is expressed in almost all cells as a constitutive survival factor.
c-Myc is another oncogene that plays a role in the production of pro-growth genes. It is the end product of the beta-catenin pathway. Finally, kRAS is a tyrosine kinase oncogene that signals downstream from a number of growth-factor receptors, such as EGFR. It is mutated or somewhere in its pathway in almost all tumors.
In summary, the development of colorectal cancer involves the accumulation of mutations in tumor suppressor genes and oncogenes. While p53 is the most important tumor suppressor gene, loss of its function is a late event in colorectal carcinogenesis. APC, Bcl-2, c-Myc, and kRAS are other important genes involved in regulating cell growth and survival in colorectal cancer.
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This question is part of the following fields:
- Clinical Sciences
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Question 15
Correct
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A 78-year-old man presents to his GP after experiencing dizziness while gardening. During the examination, the GP detects an ejection systolic murmur that radiates to the carotids. What could be the possible cause of this finding?
Your Answer: Aortic stenosis
Explanation:Valvular Murmurs: Systolic and Diastolic Classification
Valvular murmurs are a common topic in medical examinations, and it is crucial to have a good of them. The easiest way to approach valvular murmurs is to classify them into systolic and diastolic.
If the arterial valves, such as the aortic or pulmonary valves, are narrowed, ventricular contraction will cause turbulent flow, resulting in a systolic murmur. On the other hand, if these valves are incompetent or regurgitant, blood will leak back through the valve during diastole, causing a diastolic murmur.
Similarly, the atrioventricular valves, such as the mitral and tricuspid valves, can be thought of in the same way. If these valves are regurgitant, blood will be forced back into the atria during systole, causing a systolic murmur. If they are narrowed, blood will not flow freely from the atria to the ventricles during diastole, causing a diastolic murmur.
Therefore, a systolic murmur can indicate aortic/pulmonary stenosis or mitral/tricuspid regurgitation. Clinical signs and symptoms, such as presyncope and radiation to the carotids, can help identify aortic stenosis.
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This question is part of the following fields:
- Clinical Sciences
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Question 16
Correct
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A 63-year-old woman has been experiencing vomiting for the past day due to food poisoning. What acid-base imbalance is likely to occur?
Your Answer: Metabolic alkalosis
Explanation:Acid Loss and Compensation in Vomiting
There are two possible approaches to the effects of vomiting on acid loss and compensation. The first, more simplistic way is to assume that vomiting leads to acid loss since the stomach contents contain acid. However, this overlooks the fact that vomiting also results in the loss of sodium, which can affect the body’s acid-base balance. Specifically, the sodium-/H+ antiporters in the kidneys may retain sodium at the expense of hydrogen ions, leading to metabolic alkalosis.
Regardless of the mechanism, the resulting metabolic alkalosis would trigger compensatory responses in the body. One such response would be a decrease in respiratory rate, which would help retain CO2 and lead to a compensatory respiratory acidosis. Overall, the complex interplay between acid loss and compensation in vomiting requires a more nuanced approach that takes into account the various factors involved.
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This question is part of the following fields:
- Clinical Sciences
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Question 17
Correct
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Which compound is classified as a ketone?
Your Answer: Acetoacetate
Explanation:Ketone Bodies and their Production
Ketone bodies, namely acetoacetate and beta-hydroxybutyrate, are synthesized when the levels of fatty acids in the bloodstream are elevated. This can occur during fasting, starvation, or when following a high-fat, low-carbohydrate diet. When these conditions arise, triglycerides from adipose tissue are broken down into fatty acids and re-enter the bloodstream. The fatty acids then enter liver cells and undergo beta-oxidation in the mitochondria to form acetyl CoA. As acetyl CoA accumulates, two molecules can combine to form acetoacetyl CoA, which is then converted to HMGCoA by the enzyme HMG CoA synthetase. HMGCoA lyase then changes the HMG CoA into acetoacetate, which is a ketone body.
Ketones are essential as they provide fuel for body cells during times of fasting when glucose may be scarce. Brain cells are particularly able to use ketones as a fuel source.
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This question is part of the following fields:
- Clinical Sciences
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Question 18
Correct
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A pregnant woman in her late 20s has been admitted to the hospital with suspected pre-eclampsia.
Which electrolyte is effective in treating pre-eclampsia?Your Answer: Magnesium
Explanation:Hypermagnesaemia: Causes and Symptoms
Hypermagnesaemia is a condition that occurs when there is an excess of magnesium in the body. Although hypomagnesaemia is more common in hospital inpatients, certain situations can lead to hypermagnesaemia. These include renal impairment, rhabdomyolysis, excessive oral or intravenous magnesium intake, and excessive rectal magnesium intake.
One of the treatment options for pre-eclampsia is intravenous magnesium infusion, which can also lead to hypermagnesaemia if overdosed. The clinical features of hypermagnesaemia include neuromuscular depression, respiratory depression, nausea and vomiting, flushing, hypersomnia, hypotension, and cardiac arrest. It is important to monitor magnesium levels in patients who are at risk of hypermagnesaemia to prevent any adverse effects.
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This question is part of the following fields:
- Clinical Sciences
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Question 19
Correct
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A 50-year-old male patient presents at the clinic with a confirmed diagnosis of type 2 diabetes. He has also been diagnosed with liver cirrhosis and has a history of pseudogout. Based on his medical history, you suspect that he may be suffering from haemochromatosis. Can you identify the most frequently occurring genetic abnormality associated with this condition?
Your Answer: C282Y mutation
Explanation:Genetic Mutations and Their Effects
HFE is a gene responsible for binding to transferrin, and when a mutation occurs in this gene, it can lead to haemochromatosis. The most common mutation in this gene is the C282Y allele, which is a point mutation resulting in the replacement of a cysteine residue with a tyrosine amino acid. On the other hand, the delta-F508 mutation is a deletion mutation that causes the loss of phenylalanine at position 508 in the CFTR protein, leading to the development of cystic fibrosis. Trinucleotide repeats are another type of mutation that can cause inherited neurological disorders, such as Huntington’s disease and spinocerebellar ataxia. Duchenne’s muscular dystrophy is caused by a mutation in the XP-21 gene, while phenylketonuria is caused by a mutation in phenylalanine hydroxylase (PAH).
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This question is part of the following fields:
- Clinical Sciences
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Question 20
Incorrect
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What is the main factor that determines glomerular filtration rate (GFR)?
Your Answer: Urea
Correct Answer: Glomerular hydrostatic pressure
Explanation:Glomerular Filtration Rate
Glomerular filtration rate (GFR) is the measure of how well the kidneys are functioning. It is determined by the sum of hydrostatic and osmotic forces across the glomerular membrane, which gives the overall net filtration pressure and the glomerular capillary filtration coefficient. The net filtration pressure is made up of four opposing forces, including the glomerular hydrostatic pressure promoting filtration, the hydrostatic pressure within the Bowman’s capsule opposing filtration, the osmotic pressure of the glomerular capillary plasma proteins opposing filtration, and the osmotic pressure of the proteins within the Bowman’s capsule promoting filtration.
Changes to these relative pressures can alter the GFR, which can occur in both normal physiology and pathological conditions. the factors that influence GFR is important in diagnosing and treating kidney diseases. By monitoring GFR, healthcare professionals can determine the extent of kidney damage and develop appropriate treatment plans. Overall, GFR is a crucial measure of kidney function that helps to maintain overall health and well-being.
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This question is part of the following fields:
- Clinical Sciences
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Question 21
Correct
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What antenatal biomarker is linked to the inability to form vertebral arches?
Your Answer: Raised maternal serum alpha-feto protein (AFP)
Explanation:Vertebral Arch Development and Neural Tube Defects
The vertebral arches are formed from the paravertebral somites and grow posteriorly to encase the dorsal aspect of the spinal cord. Failure of development or fusion of the vertebral arches can lead to neural tube defects, which range from anencephaly to meningomyelocele and myelocele. These defects are associated with a significantly raised maternal serum alpha-feto protein and can be detected on antenatal ultrasound scans.
Biomarkers for Down Syndrome Risk Stratification
Several biomarkers are used in the risk-stratification screening for Down syndrome. These tests, performed on maternal serum, include PAPP-A, beta-HCG, AFP, uE3, and inhibin-A. Increased risk for Down syndrome occurs when PAPP-A and AFP are reduced, beta-HCG and inhibin-A are raised, and uE3 is reduced. These tests are used in combination with nuchal fold thickness to provide risk stratification for trisomy 21. Mothers of high-risk fetuses are offered diagnostic testing, such as amniocentesis or chorionic villus sampling.
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This question is part of the following fields:
- Clinical Sciences
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Question 22
Correct
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In which section of the digestive system are Brunner's glands located?
Your Answer: Duodenum
Explanation:Glands and Structures of the Digestive System
The digestive system is composed of various glands and structures that play important roles in the digestion and absorption of nutrients. One of these structures is the Brunner’s glands, which are coiled glands found in the submucosa of the duodenum. These glands produce an alkaline fluid that helps neutralize the acidic contents of the stomach as they enter the small intestine.
In contrast, salivary glands are typical exocrine glands that are composed of acini and ducts. These glands produce saliva, which contains enzymes that begin the process of breaking down carbohydrates in the mouth.
The stomach has deep pits that contain different cell types, including endocrine cells and goblet cells. These cells secrete various substances that aid in digestion and protect the stomach lining from the corrosive effects of gastric acid.
The jejunum and ileum are parts of the small intestine that have villi, which are finger-like projections that increase the surface area for absorption. At the base of the villi are the crypts of Lieberkuhn, where new enterocytes are produced and migrate up to the tip of the villi. These enterocytes are responsible for absorbing nutrients from the digested food.
Overall, the digestive system is a complex network of glands and structures that work together to ensure the proper digestion and absorption of nutrients from the food we eat.
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This question is part of the following fields:
- Clinical Sciences
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Question 23
Incorrect
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Which bone structure forms the anterior cranial fossa?
Your Answer: The sella turcica
Correct Answer: The lesser wing of the sphenoid
Explanation:Formation of the Anterior Cranial Fossa
The anterior cranial fossa is the front part of the skull base that houses the frontal lobes of the brain. It is formed by three bones: the frontal bone, the sphenoid bone, and the ethmoid bone. The orbital plate of the frontal bone makes up the front part of the fossa, while the lesser wing of the sphenoid bone forms the sides. The cribriform plate of the ethmoid bone makes up the back part of the fossa. These three bones come together to create a bony structure that protects the brain and supports the facial structures. The anterior cranial fossa is an important area of the skull as it contains the olfactory bulbs, which are responsible for the sense of smell. Any damage to this area can result in a loss of smell or other neurological deficits.
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This question is part of the following fields:
- Clinical Sciences
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Question 24
Correct
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You are participating in a seminar about eating disorders. What renal alteration is common in individuals with extreme malnourishment?
Your Answer: Reduced glomerular filtration rate
Explanation:Renal Physiology Changes in Severe Malnutrition
Patients with severe malnutrition experience changes in their renal physiology due to reduced food intake. These changes include an increased secretion of aldosterone and a reduced glomerular filtration rate (GFR), which alters the excretion patterns of many solutes, electrolytes, and drugs. As a result, there is an increased urinary excretion of potassium, calcium, magnesium, and phosphate, leading to a tendency for hypokalaemia, hypocalcaemia, hypomagnesaemia, and hypophosphataemia over time.
Furthermore, the reduced muscle bulk in individuals with severe malnutrition causes low levels of production of urea and creatinine. However, reduced excretion causes plasma levels to remain normal or only slightly reduced. As muscle is broken down to provide substrates for gluconeogenesis, a negative nitrogen balance ensues. Additionally, urate excretion is reduced, causing a relative hyperuricaemia.
In summary, severe malnutrition affects renal physiology, leading to altered excretion patterns of various solutes, electrolytes, and drugs. These changes can result in imbalances in potassium, calcium, magnesium, and phosphate levels. Furthermore, the breakdown of muscle tissue can cause a negative nitrogen balance, while reduced urate excretion can lead to hyperuricaemia.
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This question is part of the following fields:
- Clinical Sciences
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Question 25
Incorrect
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A teenager presents to the emergency department, having accidentally stabbed himself in the hand with a knife whilst cooking two days ago.
On examination there is extreme tenderness and audible crackling when you press in the palm of the hand, just around the wound.
What is the most likely organism?Your Answer: Escherichia coli
Correct Answer: Clostridium perfringens
Explanation:Gas Gangrene: A Deadly Infection
Gas gangrene, also known as necrotising fasciitis, is a severe infection that affects the skin and underlying soft tissue. While Streptococcus species are often the cause of this condition, the patient’s history suggests that a clostridial infection is more likely. Clostridium perfringens is the most common cause of gas gangrene, and its spores can be found in soil and human or animal faeces. This bacterium produces a potent toxin called alpha toxin or lecithinase, which rapidly breaks down skin and muscle, leading to the formation of gas bubbles.
The treatment for gas gangrene involves urgent surgical debridement and antibiotics.
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This question is part of the following fields:
- Clinical Sciences
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Question 26
Incorrect
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What is the highest level of evidence in the hierarchy of evidence based medicine?
Your Answer: A well-conducted randomised controlled trial
Correct Answer: A well-conducted meta-analysis of randomised controlled trials
Explanation:The Hierarchy of Evidence in Healthcare
In healthcare, evidence-based practice is crucial in making informed decisions about patient care. The hierarchy of evidence is a framework used to determine the strength and reliability of research studies. At the top of the hierarchy is a meta-analysis, which combines data from multiple studies to provide the most comprehensive and reliable evidence. Randomised controlled trials follow, which are considered the gold standard in clinical research. Cohort studies and case-control studies are next in the hierarchy, followed by case series. At the bottom of the hierarchy is expert opinion, which is based on the experience and knowledge of healthcare professionals.
It is important to note that an evidence-based guideline is not included in the hierarchy of evidence, as it relies on the hierarchy to determine the strength of the evidence used to create the guideline. By following the hierarchy of evidence, healthcare professionals can make informed decisions about patient care based on the most reliable and trustworthy evidence available.
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This question is part of the following fields:
- Clinical Sciences
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Question 27
Correct
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A 10-year-old boy comes to the clinic complaining of an itchy right ear that has been bothering him for the past five days. During the examination, he winces in pain when the outer ear is touched. Can you identify which part of the ear is considered the outer ear?
Your Answer: Pinna
Explanation:Earache: Types and Anatomy of the Ear
Earache can be categorized into two types: otitis media and otitis externa. Otitis media refers to the inflammation of the middle ear, while otitis externa is the inflammation of the outer ear and/or canal. Pain on touch or gentle pulling of the outer ear is commonly associated with otitis externa.
The outer ear is composed of the visible part of the ear, called the pinna, and the external auditory meatus near the tragus. The external auditory meatus extends from the pinna around 26 mm to the tympanic membrane. On the other hand, the middle ear reaches from the tympanic membrane to the oval window of the cochlea. This space contains three ossicles, namely the malleus, incus, and stapes, which transmit sound waves to the inner ear.
The inner ear is made up of the cochlea, which is responsible for hearing, and the vestibular apparatus, which helps maintain balance. The vestibular apparatus consists of three semicircular canals and the vestibule.
the anatomy of the ear and the different types of earache can help in identifying and treating ear problems. It is important to seek medical attention if experiencing ear pain or discomfort.
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This question is part of the following fields:
- Clinical Sciences
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Question 28
Correct
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Which anatomical feature travels posterior to the medial epicondyle of the humerus?
Your Answer: Ulnar nerve
Explanation:Anatomy of the Ulnar Nerve
The ulnar nerve travels behind the medial epicondyle before entering the forearm. In contrast, other structures such as the radial nerve and musculocutaneous nerve pass over the lateral epicondyle, while the radial and ulnar arteries originate in the forearm. This unique pathway of the ulnar nerve is important to understand in clinical settings, as it can be susceptible to injury or compression at the elbow. Proper knowledge of the anatomy of the ulnar nerve can aid in the diagnosis and treatment of conditions such as cubital tunnel syndrome or ulnar nerve entrapment. By studying the intricate details of the human body, healthcare professionals can better understand the complexities of the nervous system and provide optimal care for their patients.
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This question is part of the following fields:
- Clinical Sciences
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Question 29
Correct
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A 65-year-old man is on warfarin for recurrent deep vein thrombosis. His INR is usually stable at 2.5. However, during a recent clinic visit, the doctor noticed a significant decrease in the effectiveness of his warfarin. The doctor suspects that the patient may have consumed more vitamin K than usual. Can you identify a food that is high in vitamin K?
Your Answer: Spinach
Explanation:Vitamin K and Warfarin
Vitamin K is an essential nutrient that comes in two forms: vitamin K1 from plant sources and vitamin K2 from animal sources. It can be found in green vegetables like spinach, cabbage, and broccoli, as well as in liver and eggs. However, when taking warfarin, a medication used to reduce blood clotting, it is important to maintain a stable intake of vitamin K. Warfarin works by inhibiting the liver enzyme responsible for recycling vitamin K, which is necessary for the production of clotting factors II, VII, IX, and X. It takes several days for warfarin to reach a therapeutic level, as it depletes the body’s store of vitamin K. Any sudden changes in vitamin K intake can affect the medication’s effectiveness, so it is important to maintain a consistent diet while taking warfarin.
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This question is part of the following fields:
- Clinical Sciences
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Question 30
Correct
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A 78-year-old woman is admitted after a fall and is diagnosed with a fractured neck of femur. What tests should be ordered to investigate the potential presence of osteoporosis in this patient?
Your Answer: DXA scan
Explanation:DXA Scanning for Osteoporosis Diagnosis
DXA scanning is a diagnostic tool commonly used in hospitals to diagnose and monitor osteoporosis. It involves directing two x-rays towards the patient from perpendicular angles to measure density within different parts of the body. This allows for the determination of body composition and bone mineral density.
The results of a DXA scan are expressed as T and Z scores. The T score represents the number of standard deviations above or below the mean in a population of healthy young adults, while the Z score represents the number of standard deviations above or below the mean in a population of adults matched by age and sex to the patient.
In younger patients, the T and Z scores are usually similar and close to the mean. However, for older age groups, where more than 50% of people may have osteoporosis, the T score is particularly important for diagnosis. This is because a score based on expected values for an age and sex matched population may under-diagnose osteoporosis in elderly women.
Overall, DXA scanning is a valuable tool in the diagnosis and monitoring of osteoporosis, especially in older age groups where the risk of osteoporosis is higher.
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This question is part of the following fields:
- Clinical Sciences
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