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Question 1
Correct
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An aged patient is brought to the ER from a nursing home due to severe diarrhea and dehydration. She had received broad-spectrum antibiotics a week ago for a catheter-related infection, and it is suspected that she has been infected with Clostridium difficile. What would be the microscopic appearance of this organism?
Your Answer: Gram positive spore-forming rod
Explanation:Clostridium difficile and Gram Positive Bacteria
Clostridium difficile is becoming a more frequent cause of iatrogenic infection, leading to pseudomembranous colitis or antibiotic-associated colitis. This anaerobic rod can be identified through selective media as a motile, spore-forming Gram positive bacteria. However, it is easier and quicker to detect through immunoassay of toxin in a fresh stool sample.
Gram positive bacteria can be classified into rods or cocci. Rods include Bacillus, Listeria, and Clostridium species, which can be spore-forming or non-spore-forming. On the other hand, cocci species include Staphylococcus and Streptococcus species, while diplococcus includes Streptococcus and Enterococcus. the different types of Gram positive bacteria and their characteristics is crucial in identifying and treating infections caused by these microorganisms.
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This question is part of the following fields:
- Clinical Sciences
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Question 2
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 3
Correct
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What is the name of the intercellular junctional mechanism that allows cells to be electrically connected?
Your Answer: Gap junction
Explanation:Cell Junctions: Types and Functions
Gap junctions are found where two adjacent cell membranes meet, allowing for electrical communication between cells. Desmosomes are specialized proteins that help cells stick together, particularly in epithelial tissue. Tight junctions prevent water and solutes from leaking out of cells. Zonula adherens junctions are cell junctions that connect to the actin cytoskeleton. These different types of cell junctions play important roles in maintaining the structure and function of tissues in the body.
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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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You are in a nutrition clinic reviewing a 16-year-old boy with anorexia nervosa. He has a BMI of 15.5 kg/m2 and his weight is 70% the expected weight for height.
How would you classify his level of malnutrition?Your Answer: Mild undernutrition
Correct Answer: Severe undernutrition
Explanation:Malnutrition
Malnutrition is a clinical condition that occurs when there is an imbalance in the energy, protein, or other components of the diet, leading to adverse effects on the body’s health. This condition encompasses undernutrition, overnutrition, and vitamin and mineral deficiencies. Undernutrition is the most common form of malnutrition and is classified based on different grading systems used worldwide. Severe undernutrition is characterized by a weight of less than 70-75% of the expected weight for age and a BMI of less than 16 kg/m2.
To grade the severity of protein-energy malnutrition (PEM), a scale is commonly used. This scale considers the expected weight for age and BMI. A normal weight is between 90-110% of the expected weight for age and a BMI of 19-24 kg/m2. Mild undernutrition is between 85-90% of the expected weight for age and a BMI of 18-18.9 kg/m2. Moderate undernutrition is between 75-85% of the expected weight for age and a BMI of 16-17.9 kg/m2. Severe undernutrition is less than 75% of the expected weight for age and a BMI of less than 16 kg/m2.
In summary, malnutrition is a serious condition that affects many people worldwide. the different types of malnutrition and their severity can help healthcare professionals provide appropriate treatment and interventions to improve the health outcomes of those affected.
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This question is part of the following fields:
- Clinical Sciences
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Question 5
Incorrect
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A patient with familial hypercholesterolaemia who is 45 years old is undergoing treatment with high dose nicotinic acid, a derivative of vitamin B3 (niacin).
What are the primary side effects that can be anticipated with this therapy?Your Answer: Muscle aches
Correct Answer: Flushing
Explanation:The Functions and Uses of Nicotinic Acid
Nicotinic acid is a medication used to treat dyslipidaemia, a condition characterized by abnormal levels of lipids in the blood. It works by increasing high-density lipoprotein cholesterol (HDLc) and reducing low-density lipoprotein cholesterol (LDLc). However, high doses of nicotinic acid can cause flushing, a side effect that can be improved by co-administering laropiprant. On the other hand, niacin deficiency can lead to anxiety, diarrhea, and skin rashes on sun-exposed sites, while muscle aches are common with statins, another group of lipid-lowering agents.
Aside from its therapeutic uses, nicotinic acid and its derivatives have various functions within the body. It serves as a cofactor in cellular reactions, particularly in the metabolism of fatty acids and steroid hormones. It also acts as an antioxidant, protecting the liver against free radical damage. Moreover, niacin is required for DNA replication and repair, as well as for the synthesis of histone proteins that facilitate DNA storage, replication, and repair. Additionally, niacin plays a role in lipid metabolism and has been used as a lipid-lowering agent. Although poorly understood, niacin may also have a role in the regulation of blood sugar concentrations.
Overall, nicotinic acid is a versatile medication with various functions and uses in the body. Its therapeutic benefits in dyslipidaemia are significant, but its side effects should also be considered. the different roles of niacin in the body can provide insights into its potential uses in other conditions.
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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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A study recruits a random sample of 5,000 individuals over the age of 50 and asks about their use of herbs and other health supplements. Participants are then followed-up for five years. The study aims to compare the incidence of colon cancer among participants to see if the use of herbs or health supplements has any effect.
What type of study is this?Your Answer: Cohort study
Explanation:Different Types of Studies
When it comes to conducting research, it is important to understand the characteristics of different types of studies as they serve different purposes. For instance, a cohort study is typically used to investigate risk factors of diseases. On the other hand, a case-control study begins with identifying cases of a particular disease and controls who are not affected. Unlike a cohort study, a case-control study does not require waiting for the occurrence of the disease.
Qualitative studies, on the other hand, are used to explore variables that are not easily quantifiable, such as opinions and thoughts of patients. These studies are not suitable for studying the incidence and risk of diseases. Lastly, a randomized controlled trial involves researchers assigning treatment instead of participants choosing their own treatment.
In summary, the characteristics of different types of studies is crucial in selecting the appropriate research method for a particular research question.
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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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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 8
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 9
Incorrect
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A 28-year-old man with Crohn's disease is prescribed azathioprine. His doctor orders a blood test to evaluate TPMT activity. What is the doctor's primary concern?
Your Answer: Low transporter activity leading to reduced excretion of azathioprine
Correct Answer: Low enzyme activity leading to accumulation of 6-mercaptopurine
Explanation:Enzyme Deficiencies and Drug Toxicity
Enzyme deficiencies can lead to drug toxicity and adverse effects in patients. One example is TPMT deficiency, which can cause accumulation of 6-mercaptopurine, the active metabolite of azathioprine. This can result in bone marrow suppression and other serious complications. Approximately 10% of individuals have low TPMT activity, while 0.3% have very low activity, putting them at high risk for azathioprine-related toxicity.
Another example of enzyme deficiency is phenylalanine hydroxylase deficiency, which leads to the accumulation of phenylalanine. This condition, known as phenylketonuria, can be detected through neonatal screening using a blood spot taken from the heel several days after birth.
In clinical practice, many gastroenterologists will start patients on azathioprine and send for TPMT enzyme activity testing. Patients are advised to stop the drug if they experience symptoms, but to continue taking it while waiting for the results if they do not. Early detection of enzyme deficiencies can help prevent drug toxicity and improve patient outcomes.
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This question is part of the following fields:
- Clinical Sciences
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Question 10
Incorrect
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In which organ is aldosterone hormone synthesized?
Your Answer: Adrenal gland - zona fasciculata of the cortex
Correct Answer: Adrenal gland - zona glomerulosa of the cortex
Explanation:Hormones Produced by the Adrenal Glands
The adrenal glands are responsible for producing various hormones that are essential for the body’s proper functioning. The central core of the adrenal glands is called the medulla, where catecholamines such as adrenaline and noradrenaline are produced. On the other hand, the cortex surrounding the medulla is divided into three layers: zona glomerulosa, fasciculata, and reticularis. The zona glomerulosa is responsible for producing aldosterone, a mineralocorticoid hormone that promotes sodium retention and loss of potassium and hydrogen ions. Hyperaldosteronism, or excessive aldosterone production, is associated with hypertension.
Cortisol, a glucocorticoid hormone that is essential for life, is produced in the zona fasciculata. It causes increased blood sugar levels, stabilizes membranes, stimulates appetite, and suppresses the immune/hypersensitivity response. Adrenal androgens, such as DHEA and androstenedione, are produced in the zona reticularis in both males and females. However, their production is low until the adrenarche, which occurs around the time of puberty.
The renal juxtaglomerular apparatus is a specialized group of cells in the kidney that secretes renin and regulates the glomerular filtration rate to control sodium excretion. Overall, the adrenal glands play a crucial role in maintaining the body’s homeostasis by producing various hormones that regulate different physiological processes.
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This question is part of the following fields:
- Clinical Sciences
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Question 11
Incorrect
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A 20-year-old man in India is attacked by a wild dog and subsequently shows symptoms of rabies, including irritability, drooling, and seizures. The virus responsible for rabies is a rhabdovirus, which uses RNA polymerase to create a complementary RNA strand from a single strand of RNA. This newly-synthesised strand then acts as messenger-RNA (mRNA). What is the best description of the rhabdovirus genome?
Your Answer: Single stranded DNA (ssDNA)
Correct Answer: Negative-sense RNA (−RNA)
Explanation:Virus Classification Based on Genome
Viruses are categorized based on their genome, which can either be DNA or RNA. The RNA or DNA can be single or double-stranded. The genome of a virus determines its classification. The rhabdovirus, for instance, contains a single strand of RNA initially, which means that the first, second, and last answer options cannot be correct.
Positive-sense RNA viruses, such as picornavirus, flavivirus, coronavirus, and calicivirus, use the RNA strand directly as mRNA. On the other hand, negative-sense RNA viruses require RNA polymerase to copy the RNA strand and generate a complementary RNA strand, which then acts as mRNA. The rhabdovirus falls under this category. virus classification based on genome is crucial in developing effective treatments and vaccines.
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This question is part of the following fields:
- Clinical Sciences
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Question 12
Incorrect
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Activation of which receptor is believed to enhance the activity of brown fat, resulting in the production of heat/energy?
Your Answer: Alpha-1 receptor
Correct Answer: Beta-3 receptor
Explanation:The Role of Beta-3 Adrenoceptors and Brown Fat in Energy Metabolism
Fat cells were once believed to be inactive, but recent research has shown that they are actually an endocrine organ that produces hormones involved in regulating energy metabolism. One such hormone is produced by brown fat cells, which contain beta-3 adrenoceptors. These receptors are thought to stimulate lipolysis and thermogenesis, leading to increased energy expenditure. However, despite attempts to activate these receptors with agonists, no significant effect on weight or energy expenditure has been observed. Nonetheless, the discovery of the role of brown fat and beta-3 adrenoceptors in energy metabolism has opened up new avenues for research into potential treatments for obesity and related metabolic disorders.
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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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A 24-year-old man has sustained a stab wound to his thigh caused by a broken bottle. What sign indicates damage to the femoral nerve?
Your Answer: Loss of knee reflex
Explanation:Lesion of the Femoral Nerve and its Effects on Sensation and Movement
A lesion of the femoral nerve, specifically at the L2-4 levels, can result in several noticeable effects. One of the most prominent is weakness of the quadriceps femoris muscle, which leads to difficulty extending the knee. Additionally, there may be a loss of sensation over the front of the thigh and a lack of knee jerk reflex. These symptoms can significantly impact a person’s ability to move and perform daily activities.
The lateral cutaneous nerve of the thigh, which originates from the L1-2 levels, is responsible for providing sensation to the lateral aspect of the thigh and knee, as well as the lower lateral quadrant of the buttock. Meanwhile, the obturator nerve, which also originates from the L2-4 levels, supplies the adductors of the hip and sensation to the inner part of the thigh. These nerves can also be affected by a lesion, leading to further sensory and motor deficits.
Overall, a lesion of the femoral nerve can have significant consequences for a person’s mobility and sensation. the specific nerves involved and their functions can help in diagnosing and treating these types of injuries.
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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: c-Myc
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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Which type of antibody plays a crucial role in inhibiting the attachment of viruses to the apical membrane of enterocytes?
Your Answer: A
Explanation:The Functions of Different Types of Antibodies
There are various types of B cells in the gut’s mucosa, collectively known as GALT. These B cells produce IgA dimers that attach to the basal aspect of enterocytes. Using their J chain, IgA dimers pass through epithelial cells and become sIgA, which is more resistant to intraluminal enzymatic breakdown. sIgA then enters the GIT lumen, where it helps to prevent viruses from binding to epithelial cells.
The function of IgD is currently unknown, while IgE is crucial in responding to fungi, worms, and type I hypersensitivity reactions. IgG is the most specific antibody type, capable of crossing the placenta and forming antibody-antigen complexes. IgM forms pentamers and aids in activating complement.
In summary, different types of antibodies have distinct functions in the body. IgA helps to block viruses in the gut, while IgE responds to certain allergens. IgG is highly specific and can cross the placenta, while IgM activates complement. The function of IgD remains a mystery.
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This question is part of the following fields:
- Clinical Sciences
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Question 16
Incorrect
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Which blood vessel in the systemic circulation causes the highest amount of resistance to blood flow?
Your Answer: Capillaries
Correct Answer: Arterioles
Explanation:Arterioles and Total Peripheral Vascular Resistance
Arterioles play a crucial role in determining the total peripheral vascular resistance due to their small calibre, larger surface area, and higher tensile strength compared to capillaries. These vessels are responsible for regulating blood flow to the capillaries and organs by constricting or dilating. The constriction of arterioles increases resistance to blood flow, while dilation decreases resistance.
The high tensile strength of arterioles allows them to withstand the pressure of blood flow and maintain their shape, which is important for regulating blood pressure. Additionally, their larger surface area allows for more precise control of blood flow to specific areas of the body. Overall, arterioles are essential in regulating blood flow and maintaining proper blood pressure throughout the body.
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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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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 18
Correct
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What is the leading reason for hypoglycemia in adults?
Your Answer: Treated diabetes mellitus
Explanation:Hypoglycaemia in Adults
Hypoglycaemia is a condition where the blood glucose level falls below the typical fasting level, which is around <4 mmol/L for an adult. This condition can cause various symptoms, including tremors, sweating, nausea, lightheadedness, hunger, and disorientation. Severe hypoglycaemia can even lead to confusion, aggressive behaviour, and reduced consciousness. Drug-treated diabetes mellitus is the most common cause of hypoglycaemia in adults, especially due to insulin or hypoglycaemia drugs like sulphonylureas. Type 1 diabetes patients are at a higher risk of hypoglycaemia due to hypoglycaemia unawareness and blunted glucagon response. However, mild hypoglycaemia is common during fasting, pregnancy, and minor illness. Apart from diabetes, other causes of hypoglycaemia in adults include non-diabetic drugs, alcohol, hepatic failure, critical illness, hormone deficiency, malignancy, insulinoma, non-insulinoma pancreatogenous hypoglycaemia syndrome (NIPHS), and bariatric surgery. It is essential to understand the causes and symptoms of hypoglycaemia to manage the condition effectively. Early diagnosis and treatment can prevent severe complications and improve the quality of life for individuals with hypoglycaemia.
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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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What is the compound that results from the skin's exposure to sunlight and serves as the active form of vitamin D?
Your Answer: 1,25(OH)2 Vitamin D3
Explanation:The Activation of Vitamin D
Vitamin D is essential for maintaining healthy bones and can be obtained through exposure to sunlight or from the diet. The body can activate either vitamin D2 or vitamin D3 through the same pathway. The activation process involves hydroxylation, which adds a hydroxyl group to the vitamin D molecule at position 25 in the liver. This step is not rate limiting and occurs rapidly.
The next step in activation is further hydroxylation at carbon number 1 on the vitamin D molecule, which creates 1,25(OH)2 vitamin D. This step is rate limiting and requires the enzyme 1-alpha hydroxylase. If there is an abundance of activated vitamin D, the activity of the 1-alpha hydroxylase enzyme will decrease to prevent excessive activation of vitamin D. Instead, an inactive form called 24,25(OH)2 vitamin D can be produced. the activation process of vitamin D is crucial for maintaining healthy bones and overall health.
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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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A 35-year-old man arrives at the emergency department with chest pain. He confesses to using cocaine. Upon examination, his heart rate is 110 bpm and his blood pressure is 118/76 mmHg. An ECG reveals T wave inversion in leads V3-V6. What part of his heart has been impacted?
Your Answer: Posterior
Correct Answer: Anterolateral
Explanation:ECG Leads and Myocardial Infarction
The T wave inversion on an electrocardiogram (ECG) can indicate a non-ST elevation myocardial infarction (MI) caused by cocaine abuse. The ECG has different leads that correspond to different areas of the heart. The septal leads are V1-V2, the anterior leads are V3-V4, the lateral leads are V5-V6, I, and aVL, and the inferior leads are II, III, and aVF. However, detecting posterior infarcts on a 12-lead ECG can be challenging. Some medical centers use additional ECG leads V7-9 to help identify posterior infarcts.
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This question is part of the following fields:
- Clinical Sciences
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Question 21
Incorrect
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What is the function of aldosterone in the kidney?
Your Answer: Retain sodium with no effect on potassium
Correct Answer: Retain sodium and excrete potassium
Explanation:The Role of Aldosterone in Sodium and Potassium Balance
Aldosterone is a hormone that plays a crucial role in regulating the balance of sodium and potassium in the body. It is the final stage of the renin-angiotensin-aldosterone axis, which is triggered by reduced flow to the kidneys. The main function of aldosterone is to retain sodium at the expense of potassium. This helps to increase fluid volume by retaining water, which is important for maintaining blood pressure and electrolyte balance.
To maintain electrochemical balance, potassium has to be excreted to retain sodium. This means that when aldosterone levels are high, the body will excrete more potassium in the urine. Conversely, when aldosterone levels are low, the body will retain more potassium and excrete more sodium. This delicate balance is essential for proper functioning of the body’s cells and organs.
In summary, aldosterone is a hormone that helps to regulate the balance of sodium and potassium in the body. It is triggered by reduced flow to the kidneys and works to retain sodium at the expense of potassium. This helps to increase fluid volume and maintain electrolyte balance.
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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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What structures are found alongside the median nerve in the carpal tunnel?
Your Answer: Flexor digitorum profundis
Explanation:The Carpal Tunnel: A Passage for Nerves and Tendons
The carpal tunnel is a narrow passage located in the wrist that is made up of the flexor retinaculum, a band of connective tissue. This tunnel serves as a pathway for the median nerve and the tendons of the long flexor muscles of the fingers. These structures pass through the tunnel to reach the hand and fingers. However, all other structures, such as blood vessels and other nerves, are located outside of the carpal tunnel.
In summary, the carpal tunnel is a crucial passage for the median nerve and tendons of the long flexor muscles of the digits. It is formed by the flexor retinaculum and is located in the wrist. the anatomy of the carpal tunnel is important in diagnosing and treating conditions that affect the hand and wrist.
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This question is part of the following fields:
- Clinical Sciences
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Question 23
Correct
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A 55-year-old man with a BMI of 32 kg/m2 has been experiencing indigestion for a long time. He recently had an endoscopy, during which biopsy samples of his oesophagus were taken. The pathology report revealed abnormal columnar epithelium in the distal samples. Can you identify the best answer that describes this adaptive cellular response to injury?
Your Answer: Metaplasia
Explanation:There are four adaptive cellular responses to injury: atrophy, hypertrophy, hyperplasia, and metaplasia. Metaplasia is the reversible change of one fully differentiated cell type to another, usually in response to irritation. Examples include Barrett’s esophagus, bronchoalveolar epithelium undergoing squamous metaplasia due to cigarette smoke, and urinary bladder transitional epithelium undergoing squamous metaplasia due to a urinary calculi. Atrophy refers to a loss of cells, hypertrophy refers to an increase in cell size, and hyperplasia refers to an increase in cell number. Apoptosis is a specialized form of programmed cell death.
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This question is part of the following fields:
- Clinical Sciences
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Question 24
Incorrect
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An outbreak in the UK is typically defined as two or more people with similar symptoms or isolated organisms that are linked in time and place. However, in the case of a single occurrence of a rare and life threatening disease, such as Ebola virus, it may also be considered an outbreak. Which of the following is considered an outbreak in the case of a single occurrence of a rare and life threatening disease?
Your Answer: Tuberculosis
Correct Answer: Rabies
Explanation:Rabies: A Rare but Fatal Infection
Rabies is a serious infection that is almost always fatal in animals and humans. It is usually transmitted through saliva from the bite of an infected animal, with dogs being the most common mode of transmission to humans. However, rabies is rare in the UK with only four cases identified since 2000. In the European Union, fewer than five cases per year are reported, but there have been some recent outbreaks in Greece and neighbouring areas. Worldwide, the number of human rabies deaths is over 55,000 per year, mostly in developing countries, particularly South East Asia.
Pre-exposure and post-exposure prophylaxis is available for rabies, and the vaccine and/or rabies immunoglobulin can be given depending on perceived risk and based on Department of Health recommendations. It is important to consider whether a disease is rare or common in outbreaks, as the other diseases above are common infections and outbreak definitions usually involve two or more cases. Despite its rarity in some areas, rabies remains a serious and potentially fatal infection that requires prompt medical attention.
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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 55-year-old man comes to the clinic complaining of black tarry stools. Upon endoscopy, he is found to have a peptic ulcer. What is the primary risk factor for developing peptic ulcers?
Your Answer: Non-steroidal anti-inflammatory drugs (NSAIDs)
Correct Answer: Helicobacter pylori colonisation of the stomach
Explanation:Causes of Peptic Ulcers
Peptic ulcers are a common condition that can cause discomfort and pain in the stomach. The most common cause of peptic ulcers is the presence of Helicobacter pylori bacteria in the stomach. This bacteria can cause inflammation and damage to the lining of the stomach, leading to the formation of ulcers. Another common cause of peptic ulcers is the use of nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs can suppress the production of prostaglandins in the stomach, which can lead to inflammation and damage to the stomach lining.
In addition to these causes, smoking can also increase the risk of developing peptic ulcers. Smoking can suppress the production of prostaglandins in the stomach, impair mucosal blood flow, and increase gastric acid secretion. However, it is important to note that being female is not a risk factor for peptic ulcers. In fact, men are more likely to be affected by this condition. Overall, the causes of peptic ulcers can help individuals take steps to prevent and manage this condition.
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This question is part of the following fields:
- Clinical Sciences
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Question 26
Correct
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What is the main factor that determines glomerular filtration rate (GFR)?
Your 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 27
Incorrect
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A 42-year-old male is currently undergoing investigation for thoracic outlet syndrome at the vascular clinic.
Can you identify the crucial structure that passes in front of the scalene tubercle on the first rib?Your Answer: Sympathetic trunk
Correct Answer: Subclavian vein
Explanation:Anatomy of the Subclavian Vein, Artery, and Brachial Plexus
The subclavian vein, artery, and brachial plexus are important structures in the upper extremity. The subclavian vein passes over the first rib anterior to the scalene tubercle, while the subclavian artery and lowest trunk of the brachial plexus pass posteriorly. The middle scalene muscle, known as the scalenus medius, spreads toward the cervical vertebrae. The subclavian artery arises from the arch of the aorta laterally to the common carotids. The superior intercostal artery passes inferiorly and posteriorly between the first and second ribs. Finally, the sympathetic trunk is lateral to the vertebral bodies and runs the entire length of the vertebral column.
In summary, the subclavian vein, artery, and brachial plexus are located in close proximity to each other in the upper extremity. their anatomy is important for medical professionals who may need to access or treat these structures. The subclavian vein passes anteriorly over the first rib, while the subclavian artery and brachial plexus pass posteriorly. The scalenus medius muscle is located in the middle of the scalene muscles and spreads toward the cervical vertebrae. The subclavian artery arises from the arch of the aorta laterally to the common carotids, and the superior intercostal artery passes between the first and second ribs. Finally, the sympathetic trunk runs the entire length of the vertebral column and is located lateral to the vertebral bodies.
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This question is part of the following fields:
- Clinical Sciences
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Question 28
Incorrect
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A 10-year-old patient presents with recurrent skin cancer and is diagnosed with xeroderma pigmentosum. What is the defective biochemical mechanism in this disease?
Your Answer: DNA polymerisation
Correct Answer: DNA excision repair
Explanation:DNA and its Processes
Deoxyribonucleic acid (DNA) found in the epidermal cells absorbs UV light, which results in the formation of pyrimidine dimers. These dimers are then removed through the process of excision repair, where the DNA is copied and re-annealed. Failure in this process can lead to mutations in tumour suppressor genes or oncogenes, which can cause malignancy.
DNA polymerisation is the process of synthesizing DNA from nucleotides, which is driven by the enzyme DNA polymerase. On the other hand, mRNA splicing is the removal of introns from RNA to allow for exons to join together before coding. Lastly, nucleotide transition refers to a point mutation of nucleotides, such as in sickle cell anaemia. these processes is crucial in comprehending the role of DNA in the body and how it can affect our health.
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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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What is the hormone responsible for promoting glycogen synthesis?
Your Answer: Insulin
Explanation:The Role of Hormones in Glycogen Production and Blood Sugar Regulation
Glycogen is a complex glucose polymer that serves as a storage form of glucose in the body. When insulin levels are high, such as after a meal rich in carbohydrates, glycogen production is stimulated, leading to a decrease in blood sugar levels. However, when insulin levels are low and glucagon and cortisol levels are high, glycogen degradation is stimulated, releasing glucose into the bloodstream to maintain blood sugar levels until the next meal.
Insulin is a hormone that helps to lower blood sugar levels, while glucagon and cortisol work to increase blood sugar levels. ACTH, a hormone released by the pituitary gland, stimulates the release of cortisol from the adrenal glands, which can also contribute to an increase in blood sugar levels.
Antidiuretic hormone, on the other hand, plays a role in the production of concentrated urine but does not have any direct effect on glycogen production or blood sugar regulation.
In summary, the regulation of blood sugar levels and glycogen production is a complex process that involves the interplay of various hormones, including insulin, glucagon, cortisol, and ACTH. the role of these hormones can help to better manage conditions such as diabetes and hypoglycemia.
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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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What is the name of the enzyme necessary for the synthesis of cholesterol in the liver?
Your Answer: HMG Co A reductase
Explanation:Enzymes and Proteins Involved in Cholesterol Metabolism
Cholesterol synthesis in the liver and body cells requires the enzyme HMG CoA reductase, which converts HMG CoA into mevalonic acid, the first step in cholesterol production. This enzyme is a rate-limiting step and plays a crucial role in controlling the rate of cholesterol production. Statin drugs inhibit HMG CoA reductase, reducing blood cholesterol levels.
Cholesterol ester transport protein aids in transporting cholesterol esters from VLDL to HDL, allowing excess lipids to be returned to the liver in reverse cholesterol transport. Hepatic lipase is responsible for making LDL from VLDL, while lipoprotein lipase hydrolyzes triglycerides, creating fatty acids and glycerol that can enter the body’s cells. Microsomal triglyceride transfer protein is responsible for making chylomicrons in the enterocytes of the small intestine.
the roles of these enzymes and proteins is crucial in managing cholesterol levels and preventing cardiovascular diseases.
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This question is part of the following fields:
- Clinical Sciences
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