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Question 1
Correct
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What is the body's mechanism for handling excess nitrogen?
Your Answer: It is metabolised via the urea cycle
Explanation:The Urea Cycle: Processing Excess Nitrogen
Excess nitrogen in the form of ammonia or ammonium is converted into urea through the urea cycle. This process occurs mainly in the liver and allows for the excretion of excess nitrogen in the urine.
The urea cycle begins in the mitochondria, where ammonia combines with carbon dioxide and ATP to form carbamoyl phosphate. This compound then combines with ornithine to form citrulline. The process continues in the cytoplasm of the cell, where a series of reactions eventually leads to the production of urea.
Overall, the urea cycle is an important process for maintaining nitrogen balance in the body. By converting excess nitrogen into urea, the body can safely excrete it and prevent harmful buildup.
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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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A 82-year-old woman named Mrs. Smith visits her GP complaining of constant fatigue. She has a medical history of hypothyroidism and takes oral levothyroxine. Her routine blood tests reveal the following results: Hb 87 g/L (115-160), MCV 108 fL (76-96), Platelets 136 ×109/L (150-400), TSH 3.6 (0.3-5), and T4 88 (70-150). What is the appropriate treatment plan for Mrs. Smith?
Your Answer: Vitamin supplementation
Explanation:Pernicious Anaemia: An Autoimmune Disease
Pernicious anaemia is an autoimmune disease that occurs when the body produces antibodies against gastric parietal cells. These cells are responsible for producing intrinsic factor, which is necessary for the absorption of vitamin B12 in the terminal ileum. Vitamin B12 is essential for the synthesis of thymine, which is required for effective DNA synthesis. As a result, patients with pernicious anaemia may experience symptoms related to other cell lines, such as diarrhoea caused by gut mucosa turnover.
The failure of DNA synthesis leads to a large mean cell volume in erythrocytes as they mature through the erythroid cell line. Treatment for pernicious anaemia involves the replacement of vitamin B12, usually through hydroxycobalamin injections. Blood transfusions are unnecessary unless the patient is severely compromised, as they do not address the underlying problem.
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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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A 58-year-old patient presents to the clinic with a chief complaint of reduced night vision. Upon further examination, it is discovered that the patient has a medical history of pancreatic insufficiency, chronic diarrhea, and malabsorption. Can you identify which vitamin deficiency is commonly linked to issues with night vision?
Your Answer: Vitamin A
Explanation:The Role of Vitamin A in Night Vision
Vitamin A is essential for the production of rhodopsin, a protein found in the retina that is responsible for converting light into energy. This process involves the conversion of vitamin A into 11-cis retinal or all-trans retinol, which is stored in the pigment layer of the retina. Isomerase is an enzyme that plays a crucial role in the production of 11-cis retinal, which is then used to produce rhodopsin.
A deficiency in vitamin A can lead to a problem with night vision, as the body is unable to produce enough rhodopsin to respond to changes in light. This can result in difficulty seeing in low light conditions, such as when driving at night or in dimly lit environments. It is important to ensure that the body receives an adequate amount of vitamin A through a balanced diet or supplements to maintain healthy vision.
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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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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 5
Incorrect
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Which cell type gives rise to all germ cells through differentiation?
Your Answer: Ectoderm
Correct Answer: Epiblast
Explanation:Embryonic Development and Tissue Formation
During embryonic development, the epiblast layer, which originates from the inner cell mass, is located above the hypoblast. As the process of gastrulation occurs, the epiblast layer differentiates into three embryonic germ layers, namely the ectoderm, endoderm, and mesoderm. The ectoderm is responsible for forming various bodily systems such as the brain, retina, and anal canal. On the other hand, the mesoderm gives rise to the myotome, which is a tissue formed from somites that forms the body muscle wall. Additionally, the sclerotome, which is also part of the somite, develops to form most of the skull and vertebrae.
Furthermore, a dermatome is an area of skin that is supplied by a single spinal nerve. These dermatomes are important in the diagnosis of certain medical conditions that affect the skin. the different tissues formed during embryonic development is crucial in comprehending the various bodily systems and functions.
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This question is part of the following fields:
- Clinical Sciences
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Question 6
Incorrect
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A 67-year-old man presents with symptoms of altered bowel habit and weight loss for the past eight weeks. After undergoing screening for faecal occult blood, he is diagnosed with colorectal carcinoma. A biopsy reveals that the tumour has invaded the muscularis propria, but there is no evidence of metastases in the local lymph nodes. What is the likely stage of this cancer?
Your Answer: Duke's stage A
Correct Answer: Duke's stage B
Explanation:Duke’s Staging and Prognostic Value
Duke’s staging system is a useful tool in predicting the prognosis of colorectal cancer patients. The system was developed by Cuthbert Duke, a pathologist from the United Kingdom, in the 1930s. The staging system is based on the extent of tumor invasion and lymph node involvement.
Stage A refers to tumors that are confined to the mucosa, with a five-year survival rate of 90%. Stage B includes tumors that have invaded through the muscularis propria but have no lymph node involvement, with a five-year survival rate of 60%. Stage C includes tumors that have spread to the lymph nodes, with a five-year survival rate of 30%. Finally, stage D describes patients with metastatic disease.
The Duke’s staging system is a valuable tool for clinicians in determining the prognosis of colorectal cancer patients. It provides a clear of the extent of the disease and helps in making treatment decisions. The system has been widely used for many years and has proven to be a reliable predictor of survival rates.
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This question is part of the following fields:
- Clinical Sciences
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Question 7
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 8
Incorrect
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A 42-year-old male patient is experiencing acute renal failure, fever, weight loss, and livedo reticularis. Upon renal biopsy, there is evidence of neutrophilic and eosinophilic infiltration in artery walls with fibrinoid necrosis. What is the most probable circulating antibody present in this patient?
Your Answer: dsDNA
Correct Answer: ANCA
Explanation:Polyarteritis Nodosa and Associated Antibodies
Polyarteritis nodosa (PAN) is a type of vasculitis that affects medium-sized arteries, particularly those in the renal vasculature. Patients with PAN may experience vague symptoms such as malaise, weight loss, anemia, fever, and non-specific pains. However, more specific features of PAN include acute renal failure with beading of the renal vessel on angiography, livedo reticularis, the presence of pANCA in the blood, and granulomas with eosinophilic infiltrate on biopsy. While the majority of PAN cases are idiopathic, it can also be associated with hepatitis B virus infection.
In addition to PAN, there are other autoimmune or inflammatory conditions that may be associated with specific antibodies. For example, anti-mitochondrial antibody (AMA) is strongly associated with primary biliary cirrhosis, while Antinuclear antibodies (ANA) are non-specific and may be present in conditions such as SLE, autoimmune hepatitis, post-infection, and inflammatory bowel disease. Therefore, the presence of certain antibodies can aid in the diagnosis and management of these conditions.
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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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What is the accurate statement about Purkinje fibers in the myocardium?
Your Answer: All of the above
Correct Answer: Have a conduction velocity about four to six times the rate seen in heart muscle
Explanation:Purkinje Fibres: Conductors of the Cardiac Impulse
Purkinje fibres are specialized muscle fibres found in the ventricular myocardium of the heart. These fibres are responsible for conducting the cardiac impulse at a much faster rate than normal cardiac muscle, typically four to six times faster. Unlike neuronal axons, Purkinje fibres are not myelinated.
Disorders of Purkinje fibres can lead to various arrhythmias, including ventricular fibrillation, even in patients with structurally normal hearts. It is important to understand the role of Purkinje fibres in the heart’s electrical conduction system to diagnose and treat these conditions effectively. Proper functioning of Purkinje fibres is crucial for maintaining a healthy heart rhythm.
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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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A 30-year-old bartender complains of discomfort on the outer part of his elbow. He mentions that he has had this issue in the past and was diagnosed with lateral epicondylitis, commonly known as tennis elbow.
Assuming that this current episode is due to tennis elbow, which specific movement would you anticipate to be the most painful?Your Answer: Elbow flexion
Correct Answer: Wrist extension
Explanation:Tennis Elbow and Wrist Extension
Wrist extension is the motion that is commonly linked to discomfort in tennis elbow. This is due to the fact that the lateral epicondyle of the humerus is connected to the tendinous common origin of several extensor muscles. When performing activities such as pouring water from a jug, patients frequently report experiencing pain in the outer part of their elbow.
In summary, tennis elbow is caused by the overuse of the extensor muscles that attach to the lateral epicondyle of the humerus. This results in pain and discomfort in the outer part of the elbow, particularly during activities that involve wrist extension.
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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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What medication enhances the body's metabolic rate?
Your Answer: Thyroxine
Explanation:Medications and Their Effects on Metabolic Rate
Medications can have varying effects on the body’s metabolic rate. Some medications are known to decrease metabolic rate, such as sedatives, beta blockers like propranolol, sulphonylureas used to treat diabetes, and certain chemotherapy agents. These medications can slow down the body’s processes and lead to a decrease in energy expenditure.
On the other hand, there are medications that can increase metabolic rate. Thyroxine, a hormone produced by the thyroid gland, is known to increase metabolic rate. Recombinant human growth hormone, which is used to treat growth hormone deficiency, can also increase metabolic rate. These medications can speed up the body’s processes and lead to an increase in energy expenditure.
It is important to note that the effects of medications on metabolic rate can vary from person to person and may depend on factors such as dosage and individual health conditions. It is always recommended to consult with a healthcare provider before starting or stopping any medication.
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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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Which electrolyte imbalance is frequently observed in individuals suffering from malnutrition?
Your Answer: Hyperkalaemia
Correct Answer: Hypokalaemia
Explanation:Electrolyte Abnormalities in Malnourished Individuals
Malnutrition can lead to various changes in the body’s systems and physiology, particularly in the levels of electrolytes. The most common electrolyte abnormalities in malnourished individuals are hypokalaemia, hypocalcaemia, hypophosphataemia, and hypomagnesaemia. Prolonged malnutrition can cause the body to adapt to a reduced dietary supply of minerals, resulting in changes in renal physiology such as increased aldosterone secretion and reduced glomerular filtration rate. This leads to increased urinary excretion of potassium, calcium, magnesium, and phosphate, which can cause a tendency towards electrolyte imbalances over time.
Moreover, severe malnutrition can cause reduced muscle bulk, resulting in low levels of production of urea and creatinine. However, reduced excretion can cause plasma levels to be normal or slightly reduced. As muscle breaks down to provide substrates for gluconeogenesis, a negative nitrogen balance ensues. Therefore, patients with severe malnutrition are at risk of refeeding syndrome once they start eating again or are treated with parenteral nutrition. To prevent this, prophylaxis with B vitamins, folic acid, and minerals is recommended.
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This question is part of the following fields:
- Clinical Sciences
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Question 13
Incorrect
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What is the definition of kwashiorkor?
Your Answer: Inadequate intake of vitamins
Correct Answer: Inadequate protein intake
Explanation:Malnutrition: Types and Causes
Malnutrition is a condition that can refer to both overnutrition (obesity) and undernutrition, but it is commonly used to describe the latter. Undernutrition can take different forms, with protein-energy malnutrition (PEM) being the most common. PEM can be further classified into kwashiorkor and marasmus, which are characterized by protein deficiency and inadequate consumption of both energy and protein, respectively. Kwashiorkor is associated with oedema, abdominal swelling, and fat accumulation in the liver, while marasmus leads to emaciation without oedema or abdominal swelling.
Despite being distinct clinical scenarios, kwashiorkor and marasmus are both types of protein-energy undernutrition. It is not clear why some patients develop one form of undernutrition over the other, even when they have similar diets. Malnutrition can also result from isolated vitamin or mineral deficiencies. the different types and causes of malnutrition is crucial in addressing this global health issue.
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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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What metabolic effect occurs due to an increase in insulin secretion?
Your Answer: Increased glycogenolysis
Correct Answer: Reduced gluconeogenesis
Explanation:Insulin Anabolic Effects on Glucose Uptake
Insulin is released in response to high levels of glucose in the bloodstream. Its anabolic effects are aimed at preventing further glucose production and promoting glucose uptake into cells for utilization. Insulin reduces the processes of gluconeogenesis and glycogenolysis, which prevents the release of more glucose. Additionally, insulin inhibits the release of fatty acids from adipose tissue because glucose is the preferred energy source. Insulin also increases protein synthesis in anticipation of increased glucose uptake by cells. Furthermore, glycogen synthesis is increased to store glucose for later use. Overall, insulin anabolic effects on glucose uptake help to regulate blood glucose levels and ensure that cells have enough energy to function properly.
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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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What is the most accurate definition of evidence-based medicine (EBM)?
Your Answer: EBM is the conscientious, explicit and judicious use of current best evidence in making decisions about the care of individual patients
Explanation:Evidence-Based Medicine
Evidence-based medicine (EBM) is a widely accepted approach to healthcare decision-making that involves the conscientious, explicit, and judicious use of current best evidence. This approach integrates the best available evidence with individual patient preferences to make informed decisions about patient care. While economic analyses can help allocate resources in a cost-effective manner, critical appraisal of clinical research is also an essential element of EBM.
EBM recognizes that high-quality randomized controlled trials and systematic reviews are valuable sources of evidence, but they are not the only sources. Practicing according to guidelines can be beneficial if the guidelines are evidence-based, but this is not always the case. Ultimately, the goal of EBM is to provide patients with the best possible care by using the most current and reliable evidence available while taking into account individual patient preferences and characteristics. By doing so, healthcare providers can make informed decisions that lead to better patient outcomes.
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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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A 50-year-old ex-alcoholic patient complains of significant weight loss, jaundice, and experiences pain in his right shoulder. Upon diagnosis, he is found to have hepatocellular carcinoma. Which nerve root is most likely responsible for the shoulder tip pain?
Your Answer: C2
Correct Answer: C4
Explanation:Shoulder Tip Pain and Diaphragmatic Irritation
Shoulder tip pain can be a sign of diaphragmatic irritation, which is caused by the musculo-tendinous structure that is innervated by the phrenic nerve (C3, C4, C5). This irritation can present as shoulder pain because part of the shoulder is supplied by C4 cutaneous nerves. There are many different conditions that can irritate the diaphragm, including diseases of the liver, stomach, kidneys, and lungs.
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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 10-year-old boy has been diagnosed with Duchenne muscular dystrophy due to a significantly elevated level of creatine kinase in his blood. What is the role of creatine kinase in the body?
Your Answer: To regenerate ATP for muscle contraction
Explanation:Creatine Kinase: An Enzyme for Muscle Contraction
Creatine kinase (CK), also known as creatine phosphokinase (CPK), is an enzyme that plays a crucial role in muscle tissue. Its main function is to catalyze the regeneration of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and creatine phosphate after muscle contraction. This process allows for further muscle contraction and supports sustained exertion. CK is present in many tissues, but it is most active in striated and cardiac muscle. Other tissues with CK activity include the brain, gastrointestinal tract, and bladder.
The body’s tissues contain a dimeric form of CK, which is made up of two subunits. Each subunit of CK can be made from a genetic area on chromosome 14 (CK-B) or chromosome 19 (CK-M). There are three dimeric forms (isoforms) of CK: CK-MM, CK-MB, and CK-BB. CK-MM is abundant in striated muscle tissue, while CK-MB is abundant in cardiac muscle tissue. CK-BB is abundant in the brain, gastrointestinal tract, and bladder.
In patients with muscle diseases such as Duchenne muscular dystrophy, CK-MM is released and will be the main form of CK measured. CK-MB has been widely used in the past as an aid in the diagnosis of myocardial infarction and other diseases affecting the heart muscle.
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This question is part of the following fields:
- Clinical Sciences
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Question 18
Incorrect
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What is the primary function of vitamin B12 within the human body?
Your Answer: Production of clotting factors
Correct Answer: Synthesis of DNA
Explanation:The Importance of Vitamin B12 in the Body
Vitamin B12, also known as cobalamin, is a compound that contains cobalt and is obtained from the diet. The body has limited ability to store B12, which is why it is important to consume it regularly. Vitamin B12 works closely with folate in the body and has several important roles. It is essential for the synthesis of DNA, which allows for cell replication and tissue growth. B12 and folate are both necessary for this process. Additionally, B12 is involved in the synthesis of the myelin sheath that covers nerves and speeds up nervous transmission. It also plays a role in the metabolism of amino acids to remove harmful homocysteine, the metabolism of fats, and has an antioxidant function in association with glutathione. B12 is required for bone marrow turnover to produce healthy blood cells and platelets, which means it has some role in immunity and coagulation.
However, a deficiency in vitamin B12 can lead to several signs and symptoms. These include megaloblastic anaemia, fatigue, breathlessness, abnormal bleeding due to reduced platelet production, impaired immune response due to reduced leucocyte production, poor function of tissues such as the skin and gut which require a high cell turnover to maintain function, and infertility. It is important to ensure that you are consuming enough vitamin B12 in your diet to avoid these deficiencies and maintain optimal health.
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This question is part of the following fields:
- Clinical Sciences
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Question 19
Incorrect
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A clinical research group is conducting a study on diabetes epidemiology. As part of the study, researchers are collecting data on the age profile of a sample population in India.
Among the various data collected, one of the variables was the age of a person. This was divided into four categories: under 18, 18-30, 30-50, and over 50. Respondents were asked to select one of these four options.
What is this type of variable called?Your Answer: Continuous metric variable
Correct Answer: Ordinal categorical variable
Explanation:Different Types of Data
When analyzing data, it is important to understand the different types of variables that can be encountered. One such variable is socio-economic status, which is not a numerical value but can be categorized into four ordinal categories. Ordinal categorical data has a logical order to its categorization, but mathematical functions cannot be performed with the numbers assigned to each category.
Continuous metric data, on the other hand, can take any value and allows for mathematical functions to be performed. Examples of continuous data include height and weight. Discrete metric data is numerical but only takes certain values, such as the number of children in a family. Nominal categorical data has no hierarchy or gradation, such as blood group or yes/no questions.
Normal parametric data assumes that variables are normally distributed, but this may not be the case for small sample populations. It is important to note that data can often fall into multiple categories. For example, systolic blood pressure can be considered continuous metric data, but in practice, it is often recorded as integers, making it somewhat like a discrete variable. Additionally, if a cut-off point is used, such as 140 mmHg, the data may become dichotomous and fall into the nominal category. the different types of data is crucial for accurate analysis and interpretation.
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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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In which type of liver cells do oxygen-dependent metabolic reactions occur mostly?
Your Answer: Zone 2 hepatocytes
Correct Answer: Zone 1 hepatocytes
Explanation:The Liver’s Dual Blood Supply and Cell Zones
The liver is composed of small units called acini, each with a dual blood supply from the hepatic artery and portal vein. The blood flows through the hepatic sinusoids, allowing solutes and oxygen to move freely into the hepatocytes. The blood eventually drains into the hepatic vein and back into the systemic circulation.
The hepatocytes in the periportal region, closest to the hepatic arterial and portal vein supply, are called zone 1 hepatocytes. They are highly metabolically active due to their oxygen-rich and solute-rich supply, but are also more susceptible to damage from toxins. Zone 1 hepatocytes are responsible for oxygen-requiring reactions such as the electron transport chains, Krebs’ cycle, fatty acid oxidation, and urea synthesis.
Zone 2 and 3 hepatocytes receive less oxygen and are involved in reactions requiring little or no oxygen, such as glycolysis. Ito cells store fats and vitamin A and are involved in the production of connective tissue. Kupffer cells, specialized macrophages, are part of the reticuloendothelial system and are involved in the breakdown of haemoglobulin and the removal of haem for further metabolism in the hepatocytes. Kupffer cells also play a role in immunity. In liver disease, Ito cells are thought to be fundamental in the development of fibrosis and cirrhosis.
Overall, the liver’s dual blood supply and cell zones play important roles in the metabolic and immune functions of the liver.
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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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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 22
Correct
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A 30-year-old sailor has been diagnosed with scurvy.
What is the underlying cause of scurvy?Your Answer: Vitamin C deficiency
Explanation:The Importance of Vitamins and Their Deficiencies
Vitamins play a crucial role in maintaining the body’s overall health and well-being. Scurvy, a condition caused by a deficiency in vitamin C, is commonly observed in sailors who lack access to fresh fruits and vegetables during long sea voyages. The symptoms of scurvy include a widespread rash, bleeding mucous membranes, impaired wound healing, rough skin, fatigue, and depression. Vitamin C has several essential functions in the body, including acting as an antioxidant, reducing iron and copper, synthesizing collagen, producing energy from fats, synthesizing neurotransmitters, enhancing immune function, and acting as an antihistamine.
Deficiencies in other vitamins can also lead to various health problems. A lack of vitamin B3 can cause diarrhea, confusion, and skin changes known as pellagra. Vitamin B12 deficiency can lead to macrocytic anemia and paresthesia. Vitamin A toxicity can cause bone pain, dizziness, and blurred vision, while vitamin D toxicity can lead to vomiting, bone pain, and increased urinary frequency. It is essential to maintain a balanced diet and ensure adequate intake of all essential vitamins to prevent deficiencies and maintain optimal health.
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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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Which cell in the lung tissue is responsible for producing surfactant?
Your Answer: Type II pneumocyte
Explanation:The Roles of Different Lung Cells
The lungs are composed of various types of cells that perform different functions. Type 2 pneumocytes produce surfactant, which is essential for preventing the collapse of air-filled alveoli. Alveolar macrophages, on the other hand, are responsible for recognizing and destroying pathogens that enter the lungs. Endothelial cells have diverse functions depending on their location, while goblet cells produce mucous in the lungs. Finally, type 1 pneumocytes are involved in gas exchange in the alveoli.
In summary, the lungs are a complex organ composed of different types of cells that work together to ensure proper respiratory function. Each cell type has a specific role, from producing surfactant to recognizing and destroying pathogens. the functions of these cells is crucial in maintaining healthy lungs and preventing respiratory diseases.
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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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Which foods are rich in vitamin D?
Your Answer: Spinach
Correct Answer: Salmon
Explanation:Sources of Vitamin D
Vitamin D is a crucial nutrient that is primarily produced by the body when exposed to sunlight. However, in the absence of sunlight, it is important to obtain vitamin D from dietary sources. These sources include oily fish such as salmon, mackerel, and catfish, as well as meat, eggs, and some mushrooms. It is important to note that vitamin D-containing foods are mostly animal or fish-based, which may put strict vegetarians at a greater risk of deficiency.
Vitamin D exists in two forms, D2 and D3, with dietary sources containing vitamin D3 in greater abundance than D2. It is essential to ensure that the body receives an adequate amount of vitamin D, as it plays a crucial role in maintaining bone health, regulating the immune system, and reducing the risk of certain diseases. By incorporating vitamin D-rich foods into the diet, individuals can ensure that they are meeting their daily requirements for this important nutrient.
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This question is part of the following fields:
- Clinical Sciences
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Question 25
Correct
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What is the enzyme necessary for the production of glycogen?
Your Answer: Glycogen synthase
Explanation:Enzymes Involved in Glycogen Formation
Glycogen formation is a complex process that requires the involvement of several enzymes. One of the key enzymes involved in this process is glycogen synthase, which is responsible for extending the length of glucose chains within glycogen. This is achieved by creating α1-4 glycosidic linkages between glucose molecules to form a long chain.
However, the branching on the glycogen chain is created by another enzyme known as the branching enzyme or transferase enzyme. This enzyme produces α1-6 glycosidic linkages, which create branch points on the glycogen chain.
It is important to note that the debranching enzyme and glycogen phosphorylase are not involved in glycogen production but are instead used in the breakdown of glycogen. Similarly, phosphofructokinase is an enzyme in the glycolysis pathway, while pyruvate carboxylase is required for gluconeogenesis.
In summary, glycogen formation is a complex process that involves several enzymes, including glycogen synthase and the branching enzyme. These enzymes work together to create the long chains and branch points that make up glycogen.
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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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A 50-year-old female patient presents with a lump in her groin that appears and disappears. Upon consultation, it is determined that the hernia is protruding between the pectineal (Cooper's) ligament, lacunar ligament, and femoral vein. What type of hernia is being described by the consultant?
Your Answer: Femoral
Explanation:Types of Hernias and their Borders
Hernias are a medical condition where an organ or tissue protrudes through a weak spot in the surrounding muscle or tissue. One type of hernia is the Femoral hernia, which protrudes through the femoral canal. This type of hernia is more common in women due to their pelvic structure and childbirth. The femoral ring is narrow, making it more likely for these hernias to become strangulated.
Another type of hernia is the inguinal hernia, which protrudes through the inguinal canal. Petit’s hernia protrudes through the inferior lumbar triangle, Grynfeltt’s through the superior lumbar triangle, and obturator hernias through the obturator foramen. Each type of hernia has its own unique borders and characteristics.
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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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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 28
Incorrect
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Which organ is the least probable to exhibit cells or glands that secrete mucus?
Your Answer: Oesophagus
Correct Answer: Vagina
Explanation:Epithelial Tissue in Different Parts of the Body
The lining of the vagina and oesophagus is made up of stratified squamous non-keratinising epithelium. However, mucus glands are present at the lower end of the oesophagus. The intestines, on the other hand, are lined by a simple columnar epithelium throughout the small and large intestine. Lastly, the cervix is lined by simple columnar epithelium.
In summary, the type of epithelial tissue that lines different parts of the body varies. The vagina and oesophagus have a stratified squamous non-keratinising epithelium, while the intestines have a simple columnar epithelium. The cervix is also lined by simple columnar epithelium. It is important to note that mucus glands are present at the lower end of the oesophagus. the different types of epithelial tissue in the body is crucial in identifying and treating various medical conditions.
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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 lipoprotein with the least density?
Your Answer: Chylomicron
Explanation:Lipoproteins and Cholesterol
Lipoproteins are particles that transport lipids (fats) in the bloodstream. They are classified based on their density and size. Chylomicrons are the largest and least dense lipoproteins, while HDL is the smallest and most dense. LDL and Lp(a) are in between in terms of size and density.
LDL and Lp(a) are often referred to as bad cholesterol because they are associated with atherosclerosis, a condition that can lead to heart disease. On the other hand, HDL is known as good cholesterol because it helps remove excess cholesterol from the bloodstream.
While it is not necessary to memorize the specific density and size of each lipoprotein, it is useful to know which ones are the largest/smallest and which have the highest/lowest density. lipoproteins and cholesterol can help individuals make informed decisions about their diet and lifestyle to maintain heart health.
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This question is part of the following fields:
- Clinical Sciences
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Question 30
Incorrect
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A 28-year-old individual is currently undergoing tuberculosis treatment and is being administered vitamin B6 (pyridoxine). What is the primary function of vitamin B6 in the human body?
Vitamin B6, also known as pyridoxine, plays a crucial role in various bodily functions. It is essential for the metabolism of amino acids, which are the building blocks of proteins. Vitamin B6 also aids in the production of neurotransmitters, such as serotonin and dopamine, which are responsible for regulating mood and behavior. Additionally, it is involved in the synthesis of hemoglobin, which is the protein in red blood cells that carries oxygen throughout the body. Therefore, the administration of vitamin B6 as part of tuberculosis treatment may help support the body's immune system and aid in the recovery process.Your Answer: Coagulation
Correct Answer: Production of serotonin
Explanation:The Importance of Vitamin B6 in the Human Body
Vitamin B6, also known as pyridoxine, plays a crucial role in various functions of the human body. One of its primary functions is the production of neurotransmitters such as serotonin, dopamine, and norepinephrine, which are essential for regulating mood, behavior, and cognitive processes. Additionally, vitamin B6 acts as a cofactor in cellular reactions required for collagen synthesis, lipid metabolism, and red blood cell function.
The body’s requirement for vitamin B6 increases during periods of growth, pregnancy, and lactation. Consumption of coffee and alcohol, smoking, and certain chronic diseases can also increase the body’s need for this vitamin. Moreover, a high protein diet and administration of certain medications, including azathioprine, corticosteroids, chloramphenicol, oestrogens, levo dopa, isoniazid, penicillamine, and phenytoin, can also increase the body’s demand for vitamin B6.
In some cases, pyridoxine supplementation is necessary, especially for individuals taking isoniazid for tuberculosis. The long treatment regimen required to eliminate tuberculosis increases the risk of vitamin B6 deficiency. Therefore, it is essential to ensure adequate intake of vitamin B6 through a balanced diet or supplementation to maintain optimal health.
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This question is part of the following fields:
- Clinical Sciences
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