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Question 1
Correct
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What is the structure that extends downwards in the sagittal plane between the two cerebral hemispheres?
Your Answer: The falx cerebri
Explanation:Dura Mater Structures in the Brain
The brain is a complex organ that is protected by several layers of tissue. One of these layers is the dura mater, which is a thick, fibrous membrane that covers the brain and spinal cord. Within the dura mater, there are several structures that play important roles in the functioning of the brain.
The falx cerebri is one such structure. It is a large sheet of dura mater that partially separates the two cerebral hemispheres. This separation helps to prevent damage to one hemisphere from affecting the other, and also provides support for the brain.
Another important dura mater structure is the cavernous sinus. This structure is located within the middle cranial fossa and contains several important blood vessels and nerves. Damage to the cavernous sinus can lead to serious health problems, including vision loss and paralysis.
The diaphragma sellae is a flat piece of dura mater that allows for the passage of the pituitary stalk. This structure is important for the regulation of hormones in the body, and damage to it can lead to hormonal imbalances and other health problems.
Finally, the tentorium cerebelli is a structure that separates the cerebellum from the inferior areas of the occipital lobes. This separation helps to protect the cerebellum from damage and also provides support for the brain.
Overall, the dura mater structures in the brain play important roles in protecting and supporting the brain, as well as regulating important bodily functions.
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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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How can we describe the structure of the cell membrane? This vital component is present in all mammalian cells and is composed of lipids, proteins, carbohydrates, and other structures. The arrangement of these components is often referred to as the fluid mosaic model.
Your Answer: A phospholipid bilayer with hydrophobic tails directly apposed with the hydrophilic heads facing the cytosolic and extracellular environments
Explanation:The Fluid Mosaic Model of the Cell Membrane
The cell membrane is composed of a bilayer of phospholipids with hydrophilic heads and hydrophobic tails. This arrangement allows for the passive diffusion of hydrophobic molecules while preventing the transfer of polar solutes. Cholesterol is also present in the membrane, with higher concentrations leading to greater insulation. The cell membrane is supported by a complex network of microtubules and microfilaments, which can assist in modulating the cell’s shape and allow for endocytosis and exocytosis. These processes involve the invagination of the substrate and formation of a vesicle before expelling it into the intracellular or extracellular compartment. The cytoskeleton also plays a role in internal scaffolding, cilia, filopodia, and microvilli. The fluid mosaic model of the cell membrane describes the arrangement of these components as a floating sandwich with the heads facing the cytosolic and extracellular compartments.
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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 48 month study compared two treatments for hypertension in patients over the age of 60.
The null hypothesis was that there was no difference between the two treatments.
The primary outcome was reduction of systolic blood pressure below 140 mmHg. This outcome was reached in 75% of patients taking treatment A and 80% of patients taking treatment B. The results were reported as being significant with a p-value of 0.05.
What is the correct interpretation of the P value?Your Answer: There is a 5% probability of finding this result if there is no difference between the regimens
Explanation:The Misunderstood P Value
The P value is often misunderstood and over-interpreted. It is important to note that the P value only indicates the probability of obtaining the results by chance if there was no difference between the regimens being compared. It does not provide information on the actual difference between the regimens or the likelihood of one being better than the other. This confusion has led to the increased use of confidence intervals as a more informative measure.
Goodman SN’s article Toward Evidence-Based Medical Statistics delves deeper into this issue and highlights the fallacy of relying solely on P values. It is crucial to understand the limitations of the P value and to use it in conjunction with other statistical measures to draw accurate conclusions. By doing so, we can ensure that our research is evidence-based and reliable.
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This question is part of the following fields:
- Clinical Sciences
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Question 4
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 5
Incorrect
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A 12-year-old girl complains of fainting on exertion and her teacher noticed a bluish tinge to her skin before one episode. She says she can prevent fainting by squatting down. During examination, a mid-systolic murmur is heard and her fingernails are clubbed. What is a possible cardiac reason for her clubbing?
Your Answer: Mitral regurgitation
Correct Answer: Tetralogy of Fallot
Explanation:The causes of clubbing are varied and complex. Clubbing is a medical condition that affects the fingers and toes, causing them to become enlarged and rounded. Although the exact cause of clubbing is not fully understood, it is commonly associated with respiratory, gastrointestinal, and cardiovascular disorders.
Among the cardiovascular causes of clubbing, two main conditions stand out: infective endocarditis and tetralogy of Fallot. Tetralogy of Fallot is a congenital heart disorder that is characterized by four malformations in the heart. These include ventricular septal defect, pulmonary stenosis, over-riding aorta, and right ventricular hypertrophy.
As a result of these malformations, oxygenated and deoxygenated blood mix in the patient’s body, leading to low blood oxygen saturation. This can cause a range of symptoms, including sudden cyanosis followed by syncope, which is commonly referred to as tet spells in children. In older children, squatting can help relieve these symptoms by reducing circulation to the legs and relieving syncope.
Understanding the causes of clubbing is important, particularly for medical examinations, as it can help identify underlying conditions that may require further investigation and treatment. By recognizing the signs and symptoms of clubbing, healthcare professionals can provide appropriate care and support to patients with this condition.
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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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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 7
Incorrect
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Which statement about the internal jugular vein and its relations is correct?
Your Answer: Passes posterior to the subclavian artery
Correct Answer: Lies lateral to the common carotid artery
Explanation:The Path of the Internal Jugular Vein
The internal jugular vein begins at the jugular foramen and is initially located behind the carotid artery. As it descends in the carotid sheath, it moves to the side of the internal and common carotid arteries. Eventually, it passes in front of the subclavian artery and joins with the subclavian vein to form the brachiocephalic vein. The left and right brachiocephalic veins then come together to create the superior vena cava. At the point where the internal jugular vein meets the subclavian vein, it receives a lymphatic trunk. The external jugular vein, on the other hand, drains into the subclavian vein.
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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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In which mediastinal region is the heart located?
Your Answer: The middle mediastinum
Explanation:The genetic basis of cystic fibrosis (CF) is a crucial factor in understanding this genetic disorder that affects the respiratory, digestive, and reproductive systems. CF is caused by mutations in a single gene located on chromosome 7, which encodes the cystic fibrosis transmembrane conductance regulator (CFTR) protein. This protein plays a vital role in regulating the movement of salt and water in and out of cells, particularly in the lungs and pancreas.
The likelihood of being a carrier of the CF gene is relatively high, with a chance of 1 in 20 for the general population. However, the chances of two carriers of the gene having a child with CF are much lower, at 1 in 80. This is because CF is a recessive disorder, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to develop the disease.
Understanding the genetic basis of CF is crucial for individuals and families who may be at risk of carrying the gene. Genetic testing and counseling can help identify carriers and provide information about the risks of passing on the gene to future generations. Advances in medical treatments and therapies have improved the outlook for individuals with CF, but ongoing research is needed to develop more effective treatments and ultimately find a cure.
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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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Which muscles are responsible for flexing the hip joint?
Your Answer: Adductor brevis
Correct Answer: Psoas
Explanation:Muscles and their Functions in Joint Movement
The hip joint has three main flexors, namely the iliacus, psoas, and rectus femoris muscles. These muscles are responsible for flexing the hip joint, which is the movement of bringing the thigh towards the abdomen. On the other hand, the gluteus maximus and medius muscles are involved in hip extension, which is the movement of bringing the thigh backward.
Moving on to the elbow joint, the bicep femoris muscle is one of the primary flexors. This muscle is responsible for bending the elbow, which is the movement of bringing the forearm towards the upper arm. Lastly, the adductor brevis muscle is responsible for adducting the leg at the hip joint, which is the movement of bringing the leg towards the midline of the body.
In summary, muscles play a crucial role in joint movement. the functions of these muscles can help in identifying and addressing issues related to joint movement and mobility.
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This question is part of the following fields:
- Clinical Sciences
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Question 10
Correct
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A 67-year-old woman is scheduled for a total hip replacement on her right side. The surgeon plans to use the lateral approach to access the hip joint, which involves dividing the tensor fascia lata, as well as the gluteus medius and minimus muscles. However, this approach poses a risk to the nerve supply of these muscles. Can you identify the nerve that innervates the tensor fascia lata and gluteus medius muscles?
Your Answer: Superior gluteal nerve
Explanation:Nerves and Approaches to the Hip Joint
The superior gluteal nerve originates from L4-S1 and exits the pelvis through the greater sciatic foramen. It provides innervation to the gluteus medius, gluteus minimus, and tensor fascia lata muscles. However, the nerves in danger depend on the approach used to access the hip joint.
The posterior approach involves an incision through the deep fascia and gluteus maximus, followed by division of the external rotators. This approach puts the sciatic nerve at risk. On the other hand, the anterior approach involves the planes between tensor fascia lata and sartorius, and then rectus femoris and gluteus medius. This approach endangers the lateral femoral cutaneous nerve of the thigh.
In summary, the nerves at risk during hip joint access depend on the approach used. The posterior approach puts the sciatic nerve in danger, while the anterior approach endangers the lateral femoral cutaneous nerve of the thigh. It is important for medical professionals to be aware of these potential risks to minimize complications during hip joint procedures.
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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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In which cell types can mesenchymal pluripotent stem cells undergo differentiation?
Your Answer: Mesenchymal progenitor cells
Correct Answer: Osteoblasts, adipocytes and chondrocytes
Explanation:Mesenchymal Stem Cells: A Versatile Type of Connective Tissue
The mesenchyme is a type of connective tissue that originates from the embryonic mesoderm and is composed of undifferentiated cells. During fetal development, these mesenchymal stem cells differentiate into various types of adult cells, including osteoblasts, adipocytes, and chondrocytes. Mesenchymal stem cells have a remarkable ability to self-renew, making them a valuable resource for regenerative medicine.
Osteoblasts are cells that generate bone tissue, while adipocytes are responsible for storing fat in the body. Chondrocytes, on the other hand, produce cartilage, which is essential for maintaining healthy joints. These three cell types are the primary products of mesenchymal stem cells.
It’s important to note that the other answer options are incorrect because they don’t arise from mesenchymal stem cells. Mesenchymal stem cells are a versatile type of connective tissue that holds great promise for treating a wide range of medical conditions.
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This question is part of the following fields:
- Clinical Sciences
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Question 12
Correct
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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: 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 13
Correct
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A 2-year-old child is brought back to the hospital following a seizure. The medical team suspects that the child may have an enzyme deficiency affecting fructose-1,6 bisphosphatase, an essential enzyme for gluconeogenesis. What are the possible symptoms that may result from this enzyme defect?
Your Answer: Hypoglycaemia
Explanation:Gluconeogenesis and its Differences from Glycolysis
Gluconeogenesis is a process that is similar to glycolysis, but it occurs in reverse. While most of the reactions in glycolysis are reversible, there are some that are essentially irreversible. During gluconeogenesis, these reactions are bypassed by using different enzymes. For example, hexokinase in glycolysis is reversed by glucose 6 phosphatase during gluconeogenesis. Phosphofructokinase in glycolysis is reversed by fructose 1,6 bisphosphatase during gluconeogenesis. Pyruvate kinase in glycolysis is reversed by pyruvate carboxylase and phosphoenolpyruvate (PEP) carboxykinase during gluconeogenesis.
If there is an enzyme defect or deficiency affecting fructose 1,6 bisphosphatase, it can have a profound effect on the body’s ability to perform gluconeogenesis. This means that in times of fasting, blood sugar levels cannot be maintained by gluconeogenesis, leading to hypoglycaemia, lactic acidosis, hepatomegaly, and ketone production. Children with this condition often present in infancy, when there is a relatively low tolerance for fasting for even a few hours. While individual episodes can be treated fairly easily with glucose infusion, recurrent or severe episodes can cause an increased risk of cognitive dysfunction.
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This question is part of the following fields:
- Clinical Sciences
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Question 14
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 15
Correct
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A 30-year-old woman visits her doctor. She had a health assessment for her job's insurance and was informed that she is obese with a BMI of 36 kg/m2. She is in denial and finds it hard to accept that her weight is unhealthy.
What stage of behavioral change is she demonstrating?Your Answer: Pre-contemplation
Explanation:The Importance of Lifestyle Advice in Healthcare
Giving lifestyle advice to patients is a challenging task for doctors, but it is crucial in helping patients change their unhealthy habits. The behavioural model of change is a useful tool for clinicians to guide patients through the stages of behavioural change. Although it is an oversimplification of a complex process, it can provide guidance on how to approach difficult situations.
One example of this is when a patient is in the pre-contemplation stage, where they are unwilling to accept that they need to change their behaviour. In this situation, the clinician may choose to encourage the patient towards the contemplation stage by focusing on their attitude towards their weight and any potential problems it may cause in the future. Simply giving the patient a diet plan and exercise regimen is unlikely to be effective if they do not acknowledge the problem.
In conclusion, providing lifestyle advice is an essential skill for doctors to help patients make positive changes in their lives. The behavioural model of change can be a helpful tool in guiding patients through the stages of behavioural change, but it is important to approach each patient’s situation individually and with empathy.
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This question is part of the following fields:
- Clinical Sciences
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Question 16
Correct
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A 25-year-old farmer injures his hand on barbed wire and visits his GP after four days with a painful wound. The wound is swollen, tender, and hot to the touch. Which chemical mediator is responsible for increasing vascular permeability during acute inflammation?
Your Answer: Leukotrienes C4, D4, E4 (LTC4, D4, E4)
Explanation:Increased vascular permeability is a key aspect of acute inflammation, caused by chemical mediators such as histamine, serotonin, complement components C3a and C5a, leukotrienes, oxygen free radicals, and PAF. LTB4 causes chemotaxis of neutrophils, TNF causes fever, and glycine is an inhibitory neurotransmitter that does not affect vascular permeability.
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This question is part of the following fields:
- Clinical Sciences
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Question 17
Incorrect
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What is the intracellular pathway that is triggered by NK cells and CD8+ T cells in infected cells to induce apoptosis?
Your Answer: Protein C cascade
Correct Answer: Caspase system
Explanation:Mechanisms of Cell Killing and Metabolic Pathways
NK cells and cytotoxic T cells have two ways of killing virally infected cells. The first way is through the release of perforin and granzyme, which creates small holes in the membrane of the target cell, allowing entry of granzyme. Granzyme then activates the caspase cascade, resulting in apoptosis. The second way is through ligation of Fas-receptors, which triggers the caspase cascade, also resulting in apoptosis.
The pentose phosphate pathway is a metabolic pathway that produces NADPH and riboses, which are 5-carbon sugars. This pathway is involved in the production of energy and biosynthetic precursors for the cell.
The PI3K pathway is an intracellular signaling pathway that is used by some growth-related factors, such as insulin. This pathway plays a crucial role in regulating cell growth, proliferation, and survival.
The protein C cascade is a natural antithrombotic mechanism that helps prevent blood clots from forming. This cascade is activated when there is damage to the blood vessel wall, and it helps to break down blood clots that have already formed.
The Ras-kinase pathway is the main pro-growth pathway that is activated by growth factors. This pathway plays a crucial role in regulating cell growth, proliferation, and differentiation. It is involved in many cellular processes, including cell cycle progression, cell survival, and cell migration.
Overall, these mechanisms and pathways play important roles in maintaining the health and function of cells in the body.
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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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A 30-year-old sailor has been diagnosed with scurvy.
What is the underlying cause of scurvy?Your Answer: Vitamin B12 deficiency
Correct 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 19
Incorrect
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What is a frequent reason for mortality in individuals with severe malnutrition?
Your Answer: Liver failure
Correct Answer: Infection
Explanation:The Deadly Consequences of Severe Malnutrition
Severe malnutrition is a widespread problem that affects millions of people worldwide. It is responsible for approximately 50% of deaths in childhood and infancy. One of the most common causes of death in malnourished individuals is severe infection. Malnutrition weakens the immune system, making it more difficult for the body to fight off infections. This is especially true for those living in poverty, with poor access to food, and in areas affected by famine, war, or conflict. These conditions often lead to poor water sanitation, disrupted infrastructure for sewerage, and close living quarters, which increase the likelihood of infection.
In addition to infections, arrhythmias are also a significant cause of death in people with severe malnutrition. Malnutrition often leads to hypokalaemia, a condition where there is a low level of potassium in the blood. Refeeding a malnourished person can worsen this electrolyte disturbance, creating an arrhythmogenic environment that can be fatal.
In conclusion, severe malnutrition has deadly consequences, with severe infection and arrhythmias being the leading causes of death. Addressing the root causes of malnutrition, such as poverty and poor access to food, is crucial in preventing these tragic outcomes.
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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 70-year-old man arrives at the Emergency department displaying indications and symptoms of acute coronary syndrome. Among the following cardiac enzymes, which is the most probable to increase first after a heart attack?
Your Answer: Troponin I
Correct Answer: Myoglobin
Explanation:Enzyme Markers for Myocardial Infarction
Enzyme markers are used to diagnose myocardial infarction, with troponins being the most sensitive and specific. However, troponins are not the fastest to rise and are only measured 12 hours after the event. Myoglobin, although less sensitive and specific, is the earliest marker to rise. The rise of myoglobin occurs within 2 hours of the event, with a peak at 6-8 hours and a fall within 1-2 days. Creatine kinase rises within 4-6 hours, peaks at 24 hours, and falls within 3-4 days. LDH rises within 6-12 hours, peaks at 72 hours, and falls within 10-14 days. These enzyme markers are important in the diagnosis and management of myocardial infarction.
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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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A 28-year-old female patient has come to your clinic with worries about her selenium levels. She has recently begun taking a selenium supplement.
What is the primary function of selenium in the human body?Your Answer: Coagulation
Correct Answer: Production of thyroid hormone, T3
Explanation:The Importance of Selenium in the Body
Selenium plays a crucial role in various bodily functions. One of its primary functions is the conversion of thyroid hormone T4 to T3, which requires a selenium-based enzyme called deiodinase. Additionally, selenium is an essential component of certain antioxidant enzymes, such as glutathione peroxidases, which help protect the body from oxidative damage. It also regulates cytokine production and cellular immune function, making it vital for maintaining a healthy immune system.
Selenium can be found in various food sources, including tuna, sardines, liver, meat, fish, and wholegrain bread. However, some parts of the world have selenium-deficient soils, which can lead to a deficiency in crops and, subsequently, in individuals who consume them. Patients with inflammatory bowel diseases or pancreatic disorders are also at a higher risk of selenium deficiency than healthy individuals.
A deficiency in selenium can result in poor immune strength, an increased risk of infection, heart failure, and muscle weakness. Therefore, it is crucial to ensure that the body receives an adequate amount of selenium to maintain optimal health.
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This question is part of the following fields:
- Clinical Sciences
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Question 22
Incorrect
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What is the medical term used to describe the existence of numerous small tuberculous granulomas spread throughout the lungs?
Your Answer: Post-primary tuberculous bronchopneumonia
Correct Answer: Miliary tuberculosis
Explanation:The different manifestations of tuberculosis are crucial in diagnosing and treating the disease effectively. Tuberculosis can manifest in various ways depending on the site and stage of infection. When a person first contracts tuberculosis, it can cause mid-lower zone pneumonic consolidation, which is known as the Ghon focus. Bacteria and inflammatory cells then travel to perihilar lymph nodes, forming a Ghon complex.
In most cases, the immune system will clear the active infection, leaving some dormant granulomas and asymptomatic mycobacteria in the lungs. This stage is called latent tuberculosis. However, some patients may develop a more severe form of the disease, known as primary tuberculous bronchopneumonia, where consolidation spreads from the Ghon focus to a more widespread bronchopneumonia. Other organs may also be affected.
In most cases, latent tuberculosis remains dormant for the rest of a person’s life. However, certain factors such as immunosuppression can cause the infection to become active again, leading to primary tuberculosis. This can affect any organ, but often causes an upper lobe bronchopneumonia. Miliary tuberculosis is another manifestation of the disease, caused by the systemic dissemination of tuberculosis via haematogenous spread.
This form of tuberculosis has a particular preference for forming multiple, small lesions throughout both lung fields and other organs.
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This question is part of the following fields:
- Clinical Sciences
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Question 23
Incorrect
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What clinical sign in a newborn would indicate a plasma glucose level below the normal range of 2.2 mmol/L, such as 1.6 mmol/L?
Your Answer: Aggressive behaviour
Correct Answer: Hypotonia
Explanation:Hypoglycaemia: Symptoms and Diagnosis
Hypoglycaemia occurs when the blood glucose level falls below the typical fasting level. This condition is diagnosed when Whipple’s triad is satisfied, which includes the presence of hypoglycaemia, symptoms consistent with hypoglycaemia, and resolution of symptoms when the blood glucose level normalises. Symptoms of hypoglycaemia are caused by sympathetic activity and disrupted central nervous system function due to inadequate glucose.
Assessing hypoglycaemia in neonates and infants can be challenging as they cannot communicate early symptoms. Infants may experience hypotonia, jitteriness, seizures, poor feeding, apnoea, and lethargy. On the other hand, adults and older children may experience tremor, sweating, nausea, lightheadedness, hunger, and disorientation. Severe hypoglycaemia can cause confusion, aggressive behaviour, and reduced consciousness.
Neonates with prematurity, poor feeding, or born to mothers with diabetes, gestational diabetes, or eclampsia are at high risk of hypoglycaemia. Many neonates or infants with hypoglycaemia will secrete inappropriately high amounts of insulin, such as neonatal transient hyperinsulinism or persistent hyperinsulinism. Neonates born to diabetic mothers have hyperinsulinism, which developed in utero following exposure to high amounts of glucose from the mother that cross the placenta. This usually settles within several days.
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This question is part of the following fields:
- Clinical Sciences
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Question 24
Correct
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A 20-year-old rugby player presents with a sore throat, followed by severe malaise, high fever, and confusion two days later. He had a splenectomy three years ago after rupturing his spleen during a rugby match. The consultant suspects that he may have septicaemia.
Which organism poses the highest risk to patients who have had their spleen removed?Your Answer: Streptococcus pneumoniae
Explanation:Increased Infection Risk for Patients without a Spleen
Patients who have had their spleen removed have a weakened immune system, making them less capable of fighting off encapsulated bacteria. This puts them at a higher risk of infection from Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, and Escherichia coli. While it is recommended for these patients to receive vaccinations and sometimes antibiotics, there is still a significant risk of overwhelming post-splenectomy infection (OPSI), with a lifetime risk as high as 4%. Therefore, it is important for patients without a spleen to take extra precautions to prevent infections and seek medical attention promptly if they experience any symptoms.
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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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Following a meal, what is the primary body tissue where glycogen production occurs?
Your Answer: Liver
Explanation:Glycogen Production and Structure
The liver and muscle are the primary sites of glycogen production, which serves as a storage reservoir for excess glucose. In muscle, glycogen provides a readily available source of energy to support muscle contraction and exertion. The process of glycogen formation involves the conversion of glucose into glucose-6-phosphate and glucose-1-phosphate, which are then attached to a larger molecule called UDP. This provides a platform for glucose to be added onto the glycogen polymer in straight chains through an α1-4 glycosidic linkage. Once a chain reaches around 11 residues long, a branching enzyme removes a 6-8 unit fragment to create a new branch. The highly branched structure of glycogen allows for the storage of a large amount of glucose in a relatively small area. The diagram of glycogen structure illustrates its composition of glucose chains linked by α1-4 glycosidic linkage and branch points linked by α1-6 glycosidic linkage.
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This question is part of the following fields:
- Clinical Sciences
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Question 26
Incorrect
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Which type of cell makes up the majority of yellow bone marrow?
Your Answer: Chondrocytes
Correct Answer: Adipocytes
Explanation:Anatomy of Bones and Bone Marrow
Bones are composed of two types of bone tissue: compact bone and cancellous bone. The medullary cavity is located within the cancellous bone and contains trabeculae. Blood vessels and bone marrow are also present within the cavity. The bone marrow is responsible for producing blood cells, with red marrow being the site of active haematopoiesis. Yellow marrow, on the other hand, is predominantly made up of adipocytes and fibroblasts.
Chondrocytes are specialized cells found in cartilage that secrete the collagen matrix. Fibroblasts also contribute to the extracellular matrix by secreting collagen. Haematopoietic stem cells are found in bone marrow and are the common ancestor of all haematologic cells. Megakaryocytes, which are also found in bone marrow, are the precursor to platelets. the anatomy of bones and bone marrow is crucial in their functions and the processes that occur within them.
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This question is part of the following fields:
- Clinical Sciences
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Question 27
Correct
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A 16-year-old girl is playing volleyball and suffers an anterior dislocation of her right shoulder. She is taken to the Emergency department where her humerus is reduced under sedation. Which area should be tested for sensation to determine the nerve that is most likely to have been affected during the dislocation?
Your Answer: Regimental badge distribution
Explanation:Nerve Damage from Shoulder Dislocation
Shoulder dislocation can cause damage to the axillary nerve, which is responsible for supplying sensation to the upper part of the arm. This nerve is the most likely to be affected during a dislocation. The axillary nerve also controls the deltoid muscle, which can be examined to assess motor sensation.
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This question is part of the following fields:
- Clinical Sciences
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Question 28
Correct
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A 54-year-old man with a history of acromegaly presents for a check-up. He reports experiencing pins and needles in his hands in the early morning hours, and a positive Tinel's sign. Which muscle is most likely to be weak?
Your Answer: Abductor pollicis brevis
Explanation:Carpal Tunnel Syndrome and Median Nerve Innervation
Carpal tunnel syndrome is a condition that can cause weakness in the abductor pollicis brevis muscle, which is innervated by the median nerve. This muscle, along with the opponens pollicis, is controlled by the median nerve. The flexor pollicis brevis muscle may also be innervated by either the median or ulnar nerve. In this case, the symptoms suggest carpal tunnel syndrome, which is often associated with acromegaly. Early intervention is crucial in treating carpal tunnel syndrome, as permanent nerve damage can occur if decompression is delayed.
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This question is part of the following fields:
- Clinical Sciences
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Question 29
Incorrect
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How can cardiac output be defined?
Your Answer: The rate at which the ventricle beat per minute
Correct Answer: The amount of blood ejected from the heart in one minute
Explanation:Cardiac Output
Cardiac output refers to the amount of blood that is pumped out of the heart by either ventricle, typically the left ventricle, in one minute. This is calculated by multiplying the stroke volume, which is the amount of blood ejected from the left ventricle in one contraction, by the heart rate, which is the frequency of the cardiac cycle. At rest, the typical adult has a cardiac output of approximately 5 liters per minute. However, during extreme exercise, the cardiac output can increase up to 6 times due to the increased heart rate and need for more blood circulation throughout the body.
The heart rate is the speed at which the heart beats per minute, while the stroke volume is the amount of blood ejected from the heart in one beat or contraction. The total peripheral resistance is the force that the ventricles must work against to pump an adequate volume of blood around the body. cardiac output is important in diagnosing and treating various cardiovascular conditions.
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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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Which anatomical feature travels posterior to the medial epicondyle of the humerus?
Your Answer:
Correct Answer: Ulnar nerve
Explanation:Anatomy of the Ulnar Nerve
The ulnar nerve travels behind the medial epicondyle before entering the forearm. In contrast, other structures such as the radial nerve and musculocutaneous nerve pass over the lateral epicondyle, while the radial and ulnar arteries originate in the forearm. This unique pathway of the ulnar nerve is important to understand in clinical settings, as it can be susceptible to injury or compression at the elbow. Proper knowledge of the anatomy of the ulnar nerve can aid in the diagnosis and treatment of conditions such as cubital tunnel syndrome or ulnar nerve entrapment. By studying the intricate details of the human body, healthcare professionals can better understand the complexities of the nervous system and provide optimal care for their patients.
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This question is part of the following fields:
- Clinical Sciences
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