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Question 1
Incorrect
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A 16-year-old girl visits a rheumatologist with complaints of occasional joint pain. Despite the absence of clinical synovitis, she has a Beighton score of 9 and is in good health. What is the most suitable course of action for her management?
Your Answer: Reassurance
Correct Answer: Physiotherapy
Explanation:Joint Pain in Children and Hypermobility Syndrome
Joint pain in children can have various causes, including hypermobility syndrome. This condition is characterized by increased flexibility, as opposed to hereditary connective tissue disorders. The Beighton score is a method used to assess hypermobility, which involves ten tests. A score of 9 indicates high flexibility and suggests susceptibility to hypermobility syndrome. Although there is no intrinsic joint disease or clinical synovitis, joint pain can be experienced. Physiotherapy can help strengthen the soft tissues supporting joints and reduce pain.
In mild juvenile idiopathic arthritis (JIA), which may present similarly to hypermobility syndrome, ibuprofen is the first line of management. However, if joints show clinical synovitis, methotrexate may be considered for severe JIA. It is important to reassure the child and parents that the pain is not sinister, but it is not the optimal management for this condition. Genetic conditions causing hypermobility, such as Ehlers-Danlos and Marfan syndrome, may require referral for genetic counseling, but there are no other features of these syndromes present in hypermobility syndrome.
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This question is part of the following fields:
- Paediatrics
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Question 2
Correct
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A 52-year-old woman comes to the clinic complaining of distension and pain on the right side of her abdomen. She has a BMI of 30 kg/m² and has been diagnosed with type-2 diabetes mellitus. Upon conducting liver function tests, it was found that her Alanine Transaminase (ALT) levels were elevated. To investigate further, a liver ultrasound was ordered to examine the blood flow in and out of the liver. Which of the following blood vessels provides approximately one-third of the liver's blood supply?
Your Answer: Hepatic artery proper
Explanation:Structure and Relations of the Liver
The liver is divided into four lobes: the right lobe, left lobe, quadrate lobe, and caudate lobe. The right lobe is supplied by the right hepatic artery and contains Couinaud segments V to VIII, while the left lobe is supplied by the left hepatic artery and contains Couinaud segments II to IV. The quadrate lobe is part of the right lobe anatomically but functionally is part of the left, and the caudate lobe is supplied by both right and left hepatic arteries and lies behind the plane of the porta hepatis. The liver lobules are separated by portal canals that contain the portal triad: the hepatic artery, portal vein, and tributary of bile duct.
The liver has various relations with other organs in the body. Anteriorly, it is related to the diaphragm, esophagus, xiphoid process, stomach, duodenum, hepatic flexure of colon, right kidney, gallbladder, and inferior vena cava. The porta hepatis is located on the postero-inferior surface of the liver and transmits the common hepatic duct, hepatic artery, portal vein, sympathetic and parasympathetic nerve fibers, and lymphatic drainage of the liver and nodes.
The liver is supported by ligaments, including the falciform ligament, which is a two-layer fold of peritoneum from the umbilicus to the anterior liver surface and contains the ligamentum teres (remnant of the umbilical vein). The ligamentum venosum is a remnant of the ductus venosus. The liver is supplied by the hepatic artery and drained by the hepatic veins and portal vein. Its nervous supply comes from the sympathetic and parasympathetic trunks of the coeliac plexus.
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This question is part of the following fields:
- Gastrointestinal System
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Question 3
Incorrect
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An old woman on your ward is experiencing abdominal pain and has vomited twice today. She has not had a bowel movement for three days. During your examination, you notice that her abdomen is distended and her rectum is empty.
What is the most appropriate initial treatment?Your Answer: Diagnostic laparoscopy
Correct Answer: Give IV fluids and pass a nasogastric tube for decompression
Explanation:The initial management of small bowel obstruction involves administering IV fluids and performing gastric decompression through the use of a nasogastric tube, also known as ‘drip-and-suck’. Diagnostic laparoscopy is not necessary at this stage, unless there are signs of sepsis or peritonitis. Giving a laxative such as Senna is not recommended and requesting a surgical review is not necessary at this point.
Small bowel obstruction occurs when the small intestines are blocked, preventing the passage of food, fluids, and gas. The most common causes of this condition are adhesions resulting from previous surgeries and hernias. Symptoms include diffuse, central abdominal pain, nausea and vomiting (often bilious), constipation, and abdominal distension. Tinkling bowel sounds may also be present in early stages of obstruction. Abdominal x-ray is typically the first imaging test used to diagnose small bowel obstruction, showing distended small bowel loops with fluid levels. CT is more sensitive and considered the definitive investigation, particularly in early stages of obstruction. Management involves NBM, IV fluids, and a nasogastric tube with free drainage. Conservative management may be effective for some patients, but surgery is often necessary.
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This question is part of the following fields:
- Gastrointestinal System
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Question 4
Correct
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Which one of the following options in relation to the liver is true for individuals?
Your Answer: The caudate lobe is superior to the porta hepatis
Explanation:The ligamentum venosum and caudate lobe are located on the same side as the posterior vena cava. Positioned behind the liver, the ligamentum venosum is situated in the portal triad, which includes the portal vein (not the hepatic vein). The coronary ligament layers create a bare area of the liver, leaving a void. Additionally, the porta hepatis contains both sympathetic and parasympathetic nerves.
Structure and Relations of the Liver
The liver is divided into four lobes: the right lobe, left lobe, quadrate lobe, and caudate lobe. The right lobe is supplied by the right hepatic artery and contains Couinaud segments V to VIII, while the left lobe is supplied by the left hepatic artery and contains Couinaud segments II to IV. The quadrate lobe is part of the right lobe anatomically but functionally is part of the left, and the caudate lobe is supplied by both right and left hepatic arteries and lies behind the plane of the porta hepatis. The liver lobules are separated by portal canals that contain the portal triad: the hepatic artery, portal vein, and tributary of bile duct.
The liver has various relations with other organs in the body. Anteriorly, it is related to the diaphragm, esophagus, xiphoid process, stomach, duodenum, hepatic flexure of colon, right kidney, gallbladder, and inferior vena cava. The porta hepatis is located on the postero-inferior surface of the liver and transmits the common hepatic duct, hepatic artery, portal vein, sympathetic and parasympathetic nerve fibers, and lymphatic drainage of the liver and nodes.
The liver is supported by ligaments, including the falciform ligament, which is a two-layer fold of peritoneum from the umbilicus to the anterior liver surface and contains the ligamentum teres (remnant of the umbilical vein). The ligamentum venosum is a remnant of the ductus venosus. The liver is supplied by the hepatic artery and drained by the hepatic veins and portal vein. Its nervous supply comes from the sympathetic and parasympathetic trunks of the coeliac plexus.
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This question is part of the following fields:
- Gastrointestinal System
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Question 5
Incorrect
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An academic clinician is conducting research into the 12-month effects of a new medication on blood pressure levels in patients over the age of 60. As part of their data analysis, they want to determine if there is a significant difference between blood pressure levels at baseline and after 12 months of treatment with the new medication. However, the data is non-normally distributed.
What would be the most appropriate method to assess for a significant difference between the two groups?Your Answer: Chi-squared test
Correct Answer: Wilcoxon signed-rank test
Explanation:Types of Significance Tests
Significance tests are used to determine whether the results of a study are statistically significant or simply due to chance. The type of significance test used depends on the type of data being analyzed. Parametric tests are used for data that can be measured and are usually normally distributed, while non-parametric tests are used for data that cannot be measured in this way.
Parametric tests include the Student’s t-test, which can be paired or unpaired, and Pearson’s product-moment coefficient, which is used for correlation analysis. Non-parametric tests include the Mann-Whitney U test, which compares ordinal, interval, or ratio scales of unpaired data, and the Wilcoxon signed-rank test, which compares two sets of observations on a single sample. The chi-squared test is used to compare proportions or percentages, while Spearman and Kendall rank are used for correlation analysis.
It is important to choose the appropriate significance test for the type of data being analyzed in order to obtain accurate and reliable results. By understanding the different types of significance tests available, researchers can make informed decisions about which test to use for their particular study.
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This question is part of the following fields:
- General Principles
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Question 6
Correct
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A 50-year-old man with dyspepsia is scheduled for an upper GI endoscopy. During the procedure, an irregular erythematous area is observed protruding proximally from the gastro-oesophageal junction. To confirm a diagnosis of Barrett's esophagus, which of the following cell types must be present in addition to specialised intestinal metaplasia?
Your Answer: Goblet cell
Explanation:The presence of goblet cells is a requirement for the diagnosis of Barrett’s esophagus.
Barrett’s oesophagus is a condition where the lower oesophageal mucosa is replaced by columnar epithelium, which increases the risk of oesophageal adenocarcinoma by 50-100 fold. It is usually identified during an endoscopy for upper gastrointestinal symptoms such as dyspepsia, as there are no screening programs for it. The length of the affected segment determines the chances of identifying metaplasia, with short (<3 cm) and long (>3 cm) subtypes. The prevalence of Barrett’s oesophagus is estimated to be around 1 in 20, and it is identified in up to 12% of those undergoing endoscopy for reflux.
The columnar epithelium in Barrett’s oesophagus may resemble that of the cardiac region of the stomach or that of the small intestine, with goblet cells and brush border. The single strongest risk factor for Barrett’s oesophagus is gastro-oesophageal reflux disease (GORD), followed by male gender, smoking, and central obesity. Alcohol is not an independent risk factor for Barrett’s, but it is associated with both GORD and oesophageal cancer. Patients with Barrett’s oesophagus often have coexistent GORD symptoms.
The management of Barrett’s oesophagus involves high-dose proton pump inhibitor, although the evidence base for its effectiveness in reducing the progression to dysplasia or inducing regression of the lesion is limited. Endoscopic surveillance with biopsies is recommended every 3-5 years for patients with metaplasia but not dysplasia. If dysplasia of any grade is identified, endoscopic intervention is offered, such as radiofrequency ablation, which is the preferred first-line treatment, particularly for low-grade dysplasia, or endoscopic mucosal resection.
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This question is part of the following fields:
- Gastrointestinal System
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Question 7
Correct
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What enzyme is accountable for linking Okazaki fragments, which are around 150-200 base pairs long, during the DNA replication process in eukaryotic human cells?
Your Answer: DNA ligase
Explanation:DNA ligase is an enzyme that connects Okazaki fragments on the lagging strand to create a continuous strand. This process is essential for the completion of DNA replication. DNA helicase, on the other hand, unwinds the DNA strand to allow other enzymes to access and copy the genetic information. DNA polymerase I is only present in prokaryotic cells and is not involved in joining Okazaki fragments. Similarly, DNA polymerase beta is responsible for repairing base errors in DNA replication and does not play a role in connecting Okazaki fragments.
DNA Replication in Prokaryotes vs Eukaryotes
DNA replication is the process by which genetic information is copied and passed on to the next generation of cells. In prokaryotes, DNA replication occurs in the cytoplasm, while in eukaryotes, it occurs in the nucleus. Additionally, prokaryotes have a single origin of replication, while eukaryotes have multiple origins.
During DNA replication, the double helix is unzipped by DNA helicase, creating a replication fork. Single-stranded binding proteins prevent the DNA from reannealing. DNA polymerase III elongates the leading strand in a 5′-3′ direction, while DNA polymerase I removes RNA primers and replaces them with DNA. DNA ligase seals up the fragments.
While the basic mechanisms of DNA replication are similar in prokaryotes and eukaryotes, there are some differences in the process. Understanding these differences can help researchers better understand the genetic processes of different organisms.
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This question is part of the following fields:
- General Principles
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Question 8
Incorrect
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A 12-year-old girl is being informed about the typical changes that occur during puberty by her doctor. The doctor explains that there are three main changes that usually happen before menarche. What is the order in which these changes occur?
Your Answer: Breast buds, growth of axillary hair, growth of pubic hair
Correct Answer: Breast buds, growth of pubic hair, growth of axillary hair
Explanation:The onset of menarche is preceded by three sequential physical changes: the development of breast buds, growth of pubic hair, and growth of axillary hair. These changes are brought about by the hormone estrogen, which is crucial for the process of puberty.
Puberty: Normal Changes in Males and Females
Puberty is a natural process that marks the transition from childhood to adolescence. In males, the first sign of puberty is testicular growth, which typically occurs around the age of 12. Testicular volume greater than 4 ml indicates the onset of puberty. The maximum height spurt for boys occurs at the age of 14. On the other hand, in females, the first sign of puberty is breast development, which usually occurs around the age of 11.5. The height spurt for girls reaches its maximum early in puberty, at the age of 12, before menarche. Menarche, or the first menstrual period, typically occurs at the age of 13, with a range of 11-15 years. Following menarche, there is only a slight increase of about 4% in height.
During puberty, it is normal for boys to experience gynaecomastia, or the development of breast tissue. Girls may also experience asymmetrical breast growth. Additionally, diffuse enlargement of the thyroid gland may be seen in both males and females. These changes are all part of the normal process of puberty and should not be a cause for concern.
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This question is part of the following fields:
- Endocrine System
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Question 9
Correct
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A 56-year-old woman is undergoing rituximab treatment for non-Hodgkin's lymphoma. What is the specific target of rituximab?
Your Answer: CD20
Explanation:Monoclonal antibodies are becoming increasingly important in the field of medicine. They are created using a technique called somatic cell hybridization, which involves fusing myeloma cells with spleen cells from an immunized mouse to produce a hybridoma. This hybridoma acts as a factory for producing monoclonal antibodies.
However, a major limitation of this technique is that mouse antibodies can be immunogenic, leading to the formation of human anti-mouse antibodies. To overcome this problem, a process called humanizing is used. This involves combining the variable region from the mouse body with the constant region from a human antibody.
There are several clinical examples of monoclonal antibodies, including infliximab for rheumatoid arthritis and Crohn’s, rituximab for non-Hodgkin’s lymphoma and rheumatoid arthritis, and cetuximab for metastatic colorectal cancer and head and neck cancer. Monoclonal antibodies are also used for medical imaging when combined with a radioisotope, identifying cell surface markers in biopsied tissue, and diagnosing viral infections.
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This question is part of the following fields:
- General Principles
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Question 10
Incorrect
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A 10-year-old male presents with recurrent swollen joints which are painful. His parents have noticed this is usually precipitated by minor accidents while playing on the playground. A plasma factor assay is requested which reveals a diagnosis of haemophilia A.
Which of the following tests is most likely to be normal in this patient?Your Answer: Factor VIII levels
Correct Answer: Bleeding time
Explanation:Bleeding time is typically unaffected by haemophilia as it is a disorder of secondary haemostasis and does not impact platelets. However, APTT is likely to be prolonged due to a deficiency in factor VIII, which is reduced in haemophilia A. The disruption of the coagulation cascade is a result of this factor VIII deficiency. In cases of severe haemophilia A with significant blood loss, haemoglobin levels may be low.
Haemophilia is a genetic disorder that affects blood coagulation and is inherited in an X-linked recessive manner. It is possible for up to 30% of patients to have no family history of the condition. Haemophilia A is caused by a deficiency of factor VIII, while haemophilia B, also known as Christmas disease, is caused by a lack of factor IX.
The symptoms of haemophilia include haemoarthroses, haematomas, and prolonged bleeding after surgery or trauma. Blood tests can reveal a prolonged APTT, while the bleeding time, thrombin time, and prothrombin time are normal. However, up to 10-15% of patients with haemophilia A may develop antibodies to factor VIII treatment.
Overall, haemophilia is a serious condition that can cause significant bleeding and other complications. It is important for individuals with haemophilia to receive appropriate medical care and treatment to manage their symptoms and prevent further complications.
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This question is part of the following fields:
- Haematology And Oncology
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Question 11
Correct
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During a block dissection of the thigh, the sartorius muscle is identified. What is the nerve supply to this muscle?
Your Answer: Anterior division of the femoral nerve
Explanation:The superficial femoral nerve primarily provides cutaneous branches, but it also innervates the sartorius muscle.
The Sartorius Muscle: Anatomy and Function
The sartorius muscle is the longest strap muscle in the human body and is located in the anterior compartment of the thigh. It is the most superficial muscle in this region and has a unique origin and insertion. The muscle originates from the anterior superior iliac spine and inserts on the medial surface of the body of the tibia, anterior to the gracilis and semitendinosus muscles. The sartorius muscle is innervated by the femoral nerve (L2,3).
The primary action of the sartorius muscle is to flex the hip and knee, while also slightly abducting the thigh and rotating it laterally. It also assists with medial rotation of the tibia on the femur, which is important for movements such as crossing one leg over the other. The middle third of the muscle, along with its strong underlying fascia, forms the roof of the adductor canal. This canal contains important structures such as the femoral vessels, the saphenous nerve, and the nerve to vastus medialis.
In summary, the sartorius muscle is a unique muscle in the anterior compartment of the thigh that plays an important role in hip and knee flexion, thigh abduction, and lateral rotation. Its location and relationship to the adductor canal make it an important landmark for surgical procedures in the thigh region.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 12
Incorrect
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A 55-year-old man is scheduled to undergo a splenectomy to treat his refractory haemolytic anaemia, which is believed to be caused by a Type 2 hypersensitivity response. What is the primary mechanism involved in this process?
A) Deposition of immune complexes
B) Cell-mediated immune response
C) IgE-mediated response
D) Formation of autoantibodies against cell surface antigens
E) None of the aboveYour Answer: Cell mediated immune response
Correct Answer: Formation of autoantibodies against cell surface antigens
Explanation:Type 2 hypersensitivity reactions, such as haemolytic anaemia, involve the production of antibodies against cell surface antigens.
Classification of Hypersensitivity Reactions
Hypersensitivity reactions are classified into four types according to the Gell and Coombs classification. Type I, also known as anaphylactic hypersensitivity, occurs when an antigen reacts with IgE bound to mast cells. This type of reaction is commonly seen in atopic conditions such as asthma, eczema, and hay fever. Type II hypersensitivity occurs when cell-bound IgG or IgM binds to an antigen on the cell surface, leading to autoimmune conditions such as autoimmune hemolytic anemia, ITP, and Goodpasture’s syndrome. Type III hypersensitivity occurs when free antigen and antibody (IgG, IgA) combine to form immune complexes, leading to conditions such as serum sickness, systemic lupus erythematosus, and post-streptococcal glomerulonephritis. Type IV hypersensitivity is T-cell mediated and includes conditions such as tuberculosis, graft versus host disease, and allergic contact dermatitis.
In recent times, a fifth category has been added to the classification of hypersensitivity reactions. Type V hypersensitivity occurs when antibodies recognize and bind to cell surface receptors, either stimulating them or blocking ligand binding. This type of reaction is seen in conditions such as Graves’ disease and myasthenia gravis. Understanding the classification of hypersensitivity reactions is important in the diagnosis and management of these conditions.
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This question is part of the following fields:
- General Principles
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Question 13
Correct
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A 55-year-old woman comes to her doctor complaining of fatigue, difficulty passing stool, and muscle weakness. Her lab results show:
Free T4 6 pmol/l (9-18 pmol/l)
TSH 7.2 mu/l (0.5-5.5 mu/l)
Based on the probable diagnosis, which of the following tests is most likely to be positive in this patient?Your Answer: Anti-thyroid peroxidase (anti-TPO) antibodies
Explanation:Rheumatoid factor is not the most suitable answer for a patient with hypothyroidism, despite its presence in various rheumatological conditions and healthy individuals.
Understanding Thyroid Autoantibodies
Thyroid autoantibodies are antibodies that attack the thyroid gland, causing various thyroid disorders. There are three main types of anti-thyroid autoantibodies: anti-thyroid peroxidase (anti-TPO) antibodies, TSH receptor antibodies, and thyroglobulin antibodies. Anti-TPO antibodies are present in 90% of Hashimoto’s thyroiditis cases and 75% of Graves’ disease cases. TSH receptor antibodies are found in 90-100% of Graves’ disease cases. Thyroglobulin antibodies are present in 70% of Hashimoto’s thyroiditis cases, 30% of Graves’ disease cases, and a small proportion of thyroid cancer cases.
Understanding the different types of thyroid autoantibodies is important in diagnosing and treating thyroid disorders. Hashimoto’s thyroiditis and Graves’ disease are the most common autoimmune thyroid disorders, and the presence of specific autoantibodies can help differentiate between the two. Additionally, monitoring the levels of these antibodies can help track the progression of the disease and the effectiveness of treatment. Overall, understanding thyroid autoantibodies is crucial in managing thyroid health.
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This question is part of the following fields:
- Endocrine System
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Question 14
Correct
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A 28-year-old man has just begun taking haloperidol and is worried about developing Parkinsonism due to some motor symptoms he has been experiencing. What sign during the examination would suggest a different diagnosis?
Your Answer: Babinski's sign
Explanation:Extrapyramidal symptoms such as akathisia, bradykinesia, dystonia, and tardive dyskinesia are commonly observed in Parkinsonian conditions. Babinski’s sign, which is the upward movement of the big toe upon stimulation of the sole of the foot, is normal in infants but may indicate upper motor neuron dysfunction in older individuals. The presence of these symptoms suggests a possible diagnosis of Parkinsonism, as discussed in the case.
Parkinsonism is a condition that can be caused by various factors. One of the most common causes is Parkinson’s disease, which is a degenerative disorder of the nervous system. Other causes include drug-induced Parkinsonism, which can occur as a side effect of certain medications such as antipsychotics and metoclopramide. Progressive supranuclear palsy, multiple system atrophy, Wilson’s disease, post-encephalitis, dementia pugilistica, and exposure to toxins such as carbon monoxide and MPTP can also lead to Parkinsonism.
It is important to note that not all medications that can cause Parkinsonism have the same effect. For example, domperidone does not cross the blood-brain barrier and therefore does not cause extrapyramidal side-effects. Parkinsonism can have a significant impact on a person’s quality of life, and it is important to identify the underlying cause in order to provide appropriate treatment and management. With proper care and management, individuals with Parkinsonism can lead fulfilling lives.
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This question is part of the following fields:
- Neurological System
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Question 15
Incorrect
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A 55-year-old male patient complains of sudden chest pain and is being evaluated for acute coronary syndrome. Upon fasting, his serum cholesterol level was found to be 7.1 mmol/L (<5.2). What is the best initial course of action for managing this patient?
Your Answer: Initial dietary intervention only
Correct Answer: Statin therapy
Explanation:Statin Therapy for Hypercholesterolemia in Acute Coronary Syndrome
Hypercholesterolemia is a common condition in patients with acute coronary syndrome. The initial treatment approach for such patients is statin therapy, which includes drugs like simvastatin, atorvastatin, and rosuvastatin. Statins have been proven to reduce mortality in both primary and secondary prevention studies. The target cholesterol concentration for patients with hypercholesterolemia and acute coronary syndrome is less than 5 mmol/L.
According to NICE guidance, statins should be used more widely in conjunction with a QRISK2 score to stratify risk. This will help prevent cardiovascular disease and improve patient outcomes. The guidance recommends that statins be used in patients with a 10% or greater risk of developing cardiovascular disease within the next 10 years. By using statins in conjunction with risk stratification, healthcare professionals can provide more targeted and effective treatment for patients with hypercholesterolemia and acute coronary syndrome.
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This question is part of the following fields:
- Pharmacology
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Question 16
Correct
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What is the primary function of vitamin B12 within the human body?
Your 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 17
Incorrect
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A 25-year-old male with a history of Crohn's disease visits his gastroenterologist for a routine checkup. During the appointment, he inquires about the underlying cause of his condition. Which gene variations have been associated with Crohn's disease?
Your Answer: CFTR
Correct Answer: NOD-2
Explanation:The development of Crohn’s disease is connected to a genetic abnormality in the NOD-2 gene.
Phenylketonuria is linked to the PKU mutation.
Cystic fibrosis is associated with the CFTR mutation.
Ehlers-Danlos syndrome is connected to the COL1A1 mutation.
Understanding Crohn’s Disease
Crohn’s disease is a type of inflammatory bowel disease that can affect any part of the digestive tract, from the mouth to the anus. The exact cause of Crohn’s disease is unknown, but there is a strong genetic component. Inflammation occurs in all layers of the affected area, which can lead to complications such as strictures, fistulas, and adhesions.
Symptoms of Crohn’s disease typically appear in late adolescence or early adulthood and can include non-specific symptoms such as weight loss and lethargy, as well as more specific symptoms like diarrhea, abdominal pain, and perianal disease. Extra-intestinal features, such as arthritis, erythema nodosum, and osteoporosis, are also common in patients with Crohn’s disease.
To diagnose Crohn’s disease, doctors may look for raised inflammatory markers, increased faecal calprotectin, anemia, and low levels of vitamin B12 and vitamin D. It’s important to note that Crohn’s disease shares some features with ulcerative colitis, another type of inflammatory bowel disease, but there are also important differences between the two conditions. Understanding the symptoms and diagnostic criteria for Crohn’s disease can help patients and healthcare providers manage this chronic condition more effectively.
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This question is part of the following fields:
- Gastrointestinal System
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Question 18
Incorrect
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A senior citizen visits her doctor complaining of a cough with phlegm and is given a prescription for an antibiotic that has a bacteriostatic effect. What is the probable mechanism of action of this medication, considering its bacteriostatic effect?
Your Answer: Peptidoglycan cross-linking inhibition
Correct Answer: Protein synthesis inhibition
Explanation:Antibiotics that inhibit protein synthesis are bacteriostatic, meaning they prevent bacterial growth and replication without causing cell death through mechanisms such as membrane or cell wall damage or DNA damage-induced apoptosis.
The mechanism of action of antibiotics can be categorized into inhibiting cell wall formation, protein synthesis, DNA synthesis, and RNA synthesis. Beta-lactams such as penicillins and cephalosporins inhibit cell wall formation by blocking cross-linking of peptidoglycan cell walls. Antibiotics that inhibit protein synthesis include aminoglycosides, chloramphenicol, macrolides, tetracyclines, and fusidic acid. Quinolones, metronidazole, sulphonamides, and trimethoprim inhibit DNA synthesis, while rifampicin inhibits RNA synthesis.
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This question is part of the following fields:
- General Principles
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Question 19
Incorrect
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A 55-year-old man visits his doctor for the third time complaining of general fatigue and feeling mentally cloudy. Upon conducting another blood test, the doctor discovers that the patient has extremely low levels of vitamin B12. The diagnosis is pernicious anemia caused by antibodies against intrinsic factor. What are the cells in the gastrointestinal tract responsible for secreting intrinsic factor?
Your Answer: Enteroendocrine cells
Correct Answer: Parietal cells
Explanation:The cause of pernicious anaemia is an autoimmune response that targets intrinsic factor and possibly gastric parietal cells, leading to their destruction. These cells are responsible for producing intrinsic factor, which is necessary for the absorption of vitamin B12 in the small intestine.
Pernicious anaemia is a condition that results in a deficiency of vitamin B12 due to an autoimmune disorder affecting the gastric mucosa. The term pernicious refers to the gradual and subtle harm caused by the condition, which often leads to delayed diagnosis. While pernicious anaemia is the most common cause of vitamin B12 deficiency, other causes include atrophic gastritis, gastrectomy, and malnutrition. The condition is characterized by the presence of antibodies to intrinsic factor and/or gastric parietal cells, which can lead to reduced vitamin B12 absorption and subsequent megaloblastic anaemia and neuropathy.
Pernicious anaemia is more common in middle to old age females and is associated with other autoimmune disorders such as thyroid disease, type 1 diabetes mellitus, Addison’s, rheumatoid, and vitiligo. Symptoms of the condition include anaemia, lethargy, pallor, dyspnoea, peripheral neuropathy, subacute combined degeneration of the spinal cord, neuropsychiatric features, mild jaundice, and glossitis. Diagnosis is made through a full blood count, vitamin B12 and folate levels, and the presence of antibodies.
Management of pernicious anaemia involves vitamin B12 replacement, usually given intramuscularly. Patients with neurological features may require more frequent doses. Folic acid supplementation may also be necessary. Complications of the condition include an increased risk of gastric cancer.
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This question is part of the following fields:
- Gastrointestinal System
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Question 20
Incorrect
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These thyroid function tests were obtained on a 55-year-old female who has recently been treated for hypertension:
Free T4 28.5 pmol/L (9.8-23.1)
TSH <0.02 mU/L (0.35-5.5)
Free T3 10.8 pmol/L (3.5-6.5)
She now presents with typical symptoms of hyperthyroidism.
Which medication is likely to have caused this?Your Answer: Atenolol
Correct Answer: Amiodarone
Explanation:Amiodarone and its Effects on Thyroid Function
Amiodarone is a medication that can have an impact on thyroid function, resulting in both hypo- and hyperthyroidism. This is due to the high iodine content in the drug, which contributes to its antiarrhythmic effects. Atenolol, on the other hand, is a beta blocker that is commonly used to treat thyrotoxicosis. Warfarin is another medication that is used to treat atrial fibrillation.
There are two types of thyrotoxicosis that can be caused by amiodarone. Type 1 results in excess thyroxine synthesis, while type 2 leads to the release of excess thyroxine but normal levels of synthesis. It is important for healthcare professionals to monitor thyroid function in patients taking amiodarone and adjust treatment as necessary to prevent complications.
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This question is part of the following fields:
- Endocrine System
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Question 21
Incorrect
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A 61-year-old man arrives at the ED less than an hour after experiencing central chest pain that spreads to his left arm. His ECG reveals ST-elevation in the anterior leads, and he is set to undergo urgent PCI. The cardiologist plans to access the femoral artery. What is the accurate surface landmark for identifying the femoral artery?
Your Answer: Two thirds of the way between the ASIS and the pubic tubercle
Correct Answer: Midway between the ASIS and the pubic symphysis
Explanation:The mid-inguinal point, which is the surface landmark for the femoral artery, is located at the midpoint between the ASIS and pubic symphysis. It should not be confused with the midpoint of the inguinal ligament, which is where the deep inguinal ring is located and runs from the ASIS to the pubic tubercle. While the other three options are not specific surface landmarks, it is worth noting that the superficial inguinal ring, which is the exit of the inguinal canal, is typically located superolateral to the pubic tubercle within a range of 1-2 cm.
Understanding the Anatomy of the Femoral Triangle
The femoral triangle is an important anatomical region located in the upper thigh. It is bounded by the inguinal ligament superiorly, the sartorius muscle laterally, and the adductor longus muscle medially. The floor of the femoral triangle is made up of the iliacus, psoas major, adductor longus, and pectineus muscles, while the roof is formed by the fascia lata and superficial fascia. The superficial inguinal lymph nodes and the long saphenous vein are also found in this region.
The femoral triangle contains several important structures, including the femoral vein, femoral artery, femoral nerve, deep and superficial inguinal lymph nodes, lateral cutaneous nerve, great saphenous vein, and femoral branch of the genitofemoral nerve. The femoral artery can be palpated at the mid inguinal point, making it an important landmark for medical professionals.
Understanding the anatomy of the femoral triangle is important for medical professionals, as it is a common site for procedures such as venipuncture, arterial puncture, and nerve blocks. It is also important for identifying and treating conditions that affect the structures within this region, such as femoral hernias and lymphadenopathy.
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This question is part of the following fields:
- Gastrointestinal System
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Question 22
Incorrect
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A 48-year-old patient attends the diabetic clinic with an HbA1c of 58mmol/mol. Despite his efforts to lose weight, his blood sugar levels remain high. You adjust his metformin dosage and schedule a follow-up appointment in 4 months. During the consultation, he confides in you about his difficulty in achieving and maintaining an erection, which has caused strain in his relationship. To address this issue, you prescribe a course of sildenafil. How does sildenafil improve erectile function?
Your Answer: Inhibits the breakdown of cGMP which causes an increase in intracellular calcium resulting in smooth muscle relaxation
Correct Answer: Increased penile blood due to vasodilation through an increase in cGMP
Explanation:PDE 5 inhibitors, such as sildenafil, promote vasodilation by elevating the levels of cGMP. Sildenafil works by inhibiting the cGMP-specific phosphodiesterase type 5 (PDE5) enzyme, which is responsible for breaking down cGMP in the corpus cavernosum surrounding the penis. Sexual stimulation triggers the release of nitric oxide (NO) from nerve terminals and endothelial cells, leading to the synthesis of cGMP in smooth muscle cells. This results in the relaxation of penile arteries and corpus cavernosal smooth muscle, leading to increased blood flow and penile erection. By enhancing the amount of cGMP, sildenafil improves erectile function. This is achieved by reducing intracellular calcium concentration, which causes smooth muscle relaxation. The other options are incorrect because vasoconstriction, corpus cavernosal smooth muscle contraction, and increased intracellular calcium concentration would worsen erectile dysfunction.
Phosphodiesterase type V inhibitors are medications used to treat erectile dysfunction and pulmonary hypertension. They work by increasing cGMP, which leads to relaxation of smooth muscles in blood vessels supplying the corpus cavernosum. The most well-known PDE5 inhibitor is sildenafil, also known as Viagra, which is taken about an hour before sexual activity. Other examples include tadalafil (Cialis) and vardenafil (Levitra), which have longer-lasting effects and can be taken regularly. However, these medications have contraindications, such as not being safe for patients taking nitrates or those with hypotension. They can also cause side effects such as visual disturbances, blue discolouration, and headaches. It is important to consult with a healthcare provider before taking PDE5 inhibitors.
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This question is part of the following fields:
- General Principles
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Question 23
Incorrect
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A 39-year-old male patient is presented to the neurology outpatient department by his GP due to recurring episodes of déjà vu. Apart from this, he has no significant medical history.
During the examination, the patient suddenly starts smacking his lips for about a minute. After the event, he experiences temporary difficulty in expressing himself fluently, which resolves on its own.
Based on the symptoms, which area of the brain is likely to be affected?Your Answer: Parietal lobe
Correct Answer: Temporal lobe
Explanation:Temporal lobe seizures can be identified by the presence of lip smacking and postictal dysphasia. These symptoms, along with a recurrent sense of déjà vu, suggest that the seizure is localized in the temporal lobe. Seizures in other parts of the brain, such as the frontal, occipital, or parietal lobes, typically present with different symptoms. Generalized seizures affecting the entire brain result in loss of consciousness and generalized tonic-clonic seizures.
Localising Features of Focal Seizures in Epilepsy
Focal seizures in epilepsy can be localised based on the specific location of the brain where they occur. Temporal lobe seizures are common and may occur with or without impairment of consciousness or awareness. Most patients experience an aura, which is typically a rising epigastric sensation, along with psychic or experiential phenomena such as déjà vu or jamais vu. Less commonly, hallucinations may occur, such as auditory, gustatory, or olfactory hallucinations. These seizures typically last around one minute and are often accompanied by automatisms, such as lip smacking, grabbing, or plucking.
On the other hand, frontal lobe seizures are characterised by motor symptoms such as head or leg movements, posturing, postictal weakness, and Jacksonian march. Parietal lobe seizures, on the other hand, are sensory in nature and may cause paraesthesia. Finally, occipital lobe seizures may cause visual symptoms such as floaters or flashes. By identifying the specific location and type of seizure, doctors can better diagnose and treat epilepsy in patients.
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This question is part of the following fields:
- Neurological System
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Question 24
Incorrect
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A 32-year-old woman visits her primary care physician with complaints of wrist and finger pain that has persisted for a month. Despite taking paracetamol, the pain has not subsided. The patient also reports experiencing redness on her cheeks and feeling warm, as if she has a fever. She has noticed that exposure to sunlight exacerbates the rash and has started using sunscreen. The patient works as a teacher, has no significant medical history, and no family history of musculoskeletal issues. During the examination, the doctor observes a butterfly-shaped rash on the patient's face and records a heart rate of 81 beats per minute, respiratory rate of 13 breaths per minute, and blood pressure of 143/88 mmHg. What is the most accurate description of this patient's condition?
Your Answer: Type IV delayed-type hypersensitivity reaction
Correct Answer: Type III hypersensitivity reaction
Explanation:The patient’s symptoms suggest a diagnosis of systemic lupus erythematosus, which is an autoimmune condition that primarily affects young women of childbearing age. Joint pain and fever are common symptoms, but patients may also experience oral ulcers and hematuria. Antinuclear antibodies are a sensitive test for this condition. Systemic lupus erythematosus is an example of a Type III hypersensitivity reaction, where IgG antibodies bind to soluble antigens, forming immune complexes that deposit in tissues and trigger inflammation. Other examples of Type III hypersensitivity reactions include poststreptococcal glomerulonephritis.
Classification of Hypersensitivity Reactions
Hypersensitivity reactions are classified into four types according to the Gell and Coombs classification. Type I, also known as anaphylactic hypersensitivity, occurs when an antigen reacts with IgE bound to mast cells. This type of reaction is commonly seen in atopic conditions such as asthma, eczema, and hay fever. Type II hypersensitivity occurs when cell-bound IgG or IgM binds to an antigen on the cell surface, leading to autoimmune conditions such as autoimmune hemolytic anemia, ITP, and Goodpasture’s syndrome. Type III hypersensitivity occurs when free antigen and antibody (IgG, IgA) combine to form immune complexes, leading to conditions such as serum sickness, systemic lupus erythematosus, and post-streptococcal glomerulonephritis. Type IV hypersensitivity is T-cell mediated and includes conditions such as tuberculosis, graft versus host disease, and allergic contact dermatitis.
In recent times, a fifth category has been added to the classification of hypersensitivity reactions. Type V hypersensitivity occurs when antibodies recognize and bind to cell surface receptors, either stimulating them or blocking ligand binding. This type of reaction is seen in conditions such as Graves’ disease and myasthenia gravis. Understanding the classification of hypersensitivity reactions is important in the diagnosis and management of these conditions.
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This question is part of the following fields:
- General Principles
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Question 25
Incorrect
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Which hormone triggers the breakdown of glycogen in the liver during fasting?
Your Answer: Secretin
Correct Answer: Glucagon
Explanation:Glycogen Formation and Degradation
In normal circumstances, glucose in the blood is converted into glycogen by the liver with the help of insulin and rising glucose levels. This process requires several enzymes such as phosphoglucomutase, glucose-1-phosphate uridyltransferase, glycogen synthase, and branching enzyme. However, when glucose is scarce, glycogen must be broken down to release glucose into the blood. This process is mainly stimulated by the hormone glucagon and requires the enzymes glycogen phosphorylase and debranching enzyme. Defects in either glycogen formation or degradation can lead to fasting hypoglycemia, which is a common feature of many glycogen storage disorders (GSDs).
One such disorder is glycogen synthase deficiency (GSD type 0), which typically presents in childhood with symptoms of hypoglycemia after an overnight fast. However, symptoms can be improved by administering glucose, and patients can be given corn starch to prevent symptoms in the morning. A liver biopsy will show very little glycogen, and the disease is inherited as an autosomal recessive trait. Overall, the balance between glycogen formation and degradation is crucial in maintaining normal blood sugar levels.
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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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A 7-year-old child with Downs' syndrome is experiencing recurrent ear infections. Upon referral to an ear and nose specialist, the parents are informed that the child's ear canal is narrowed, hindering proper drainage and increasing the likelihood of infections. Which pharyngeal pouch gives rise to the eustachian tube?
Your Answer: Third pharyngeal pouch
Correct Answer: First pharyngeal pouch
Explanation:The 1st pharyngeal pouch gives rise to the eustachian tube, while the 2nd pharyngeal pouch develops into the Palatine tonsils. The 3rd pharyngeal pouch gives rise to the thymus and inferior parathyroid glands, while the 4th pharyngeal pouch forms the superior parathyroid glands. The 5th pharyngeal pouch eventually becomes part of the 4th pharyngeal pouch and develops into the thyroid C-cells.
Embryology of Branchial (Pharyngeal) Pouches
During embryonic development, the branchial (pharyngeal) pouches give rise to various structures in the head and neck region. The first pharyngeal pouch forms the Eustachian tube, middle ear cavity, and mastoid antrum. The second pharyngeal pouch gives rise to the palatine tonsils. The third pharyngeal pouch divides into dorsal and ventral wings, with the dorsal wings forming the inferior parathyroid glands and the ventral wings forming the thymus. Finally, the fourth pharyngeal pouch gives rise to the superior parathyroid glands.
Understanding the embryology of the branchial pouches is important in the diagnosis and treatment of certain congenital abnormalities and diseases affecting these structures. By knowing which structures arise from which pouches, healthcare professionals can better understand the underlying pathophysiology and develop appropriate management strategies. Additionally, knowledge of the embryology of these structures can aid in the development of new treatments and therapies for related conditions.
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This question is part of the following fields:
- General Principles
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Question 27
Correct
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A 78-year-old male is admitted to your ward with community-acquired pneumonia. He has a history of Parkinson's disease for the past 6 years. The patient becomes increasingly agitated during his stay, and you notice that he is prescribed haloperidol for agitation. However, after receiving the medication, his Parkinson's symptoms worsen significantly. What is the likely mechanism of action of haloperidol?
Your Answer: Blocks dopamine receptors
Explanation:Haloperidol is a typical antipsychotic that works by blocking dopamine receptors in the brain. However, typical antipsychotics are known to have non-selective blockage of various dopamine receptors, leading to unwanted side effects such as parkinsonism. This is particularly problematic for individuals with Parkinson’s disease, as the depletion of dopaminergic neurons already present in the condition can be further exacerbated by the use of antipsychotics that block any remaining dopamine transmissions.
Antipsychotics are a type of medication used to treat schizophrenia, psychosis, mania, and agitation. They are divided into two categories: typical and atypical antipsychotics. The latter were developed to address the extrapyramidal side-effects associated with the first generation of typical antipsychotics. Typical antipsychotics work by blocking dopaminergic transmission in the mesolimbic pathways through dopamine D2 receptor antagonism. However, they are known to cause extrapyramidal side-effects such as Parkinsonism, acute dystonia, akathisia, and tardive dyskinesia. These side-effects can be managed with procyclidine. Other side-effects of typical antipsychotics include antimuscarinic effects, sedation, weight gain, raised prolactin, impaired glucose tolerance, neuroleptic malignant syndrome, reduced seizure threshold, and prolonged QT interval. The Medicines and Healthcare products Regulatory Agency has issued specific warnings when antipsychotics are used in elderly patients due to an increased risk of stroke and venous thromboembolism.
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This question is part of the following fields:
- Psychiatry
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Question 28
Incorrect
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A 25-year-old female experiences repeated anterior dislocations of her left shoulder and a CT scan shows a Bankart lesion. What is the name of the rotator cuff muscle tendon located at the front of the shoulder capsule?
Your Answer: Teres minor
Correct Answer: Subscapularis tendon
Explanation:The tendon of the subscapularis runs in front of the shoulder capsule, while the supraspinatus tendon runs above it. The tendons of the infraspinatus and teres minor run behind the shoulder capsule, with the infraspinatus tendon positioned above the teres minor tendon. It should be noted that the teres major muscle is not part of the rotator cuff. A Bankart lesion refers to a tear in the front part of the glenoid labrum and is commonly seen in cases of anterior shoulder dislocation.
Understanding the Rotator Cuff Muscles
The rotator cuff muscles are a group of four muscles that are responsible for the movement and stability of the shoulder joint. These muscles are known as the SItS muscles, which stands for Supraspinatus, Infraspinatus, teres minor, and Subscapularis. Each of these muscles has a specific function in the movement of the shoulder joint.
The Supraspinatus muscle is responsible for abducting the arm before the deltoid muscle. It is the most commonly injured muscle in the rotator cuff. The Infraspinatus muscle rotates the arm laterally, while the teres minor muscle adducts and rotates the arm laterally. Lastly, the Subscapularis muscle adducts and rotates the arm medially.
Understanding the functions of each of these muscles is important in diagnosing and treating rotator cuff injuries. By identifying which muscle is injured, healthcare professionals can develop a treatment plan that targets the specific muscle and promotes healing. Overall, the rotator cuff muscles play a crucial role in the movement and stability of the shoulder joint.
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This question is part of the following fields:
- Musculoskeletal System And Skin
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Question 29
Incorrect
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A 20-year-old female patient complains of fever and a sore throat that has been bothering her for two days. During the examination, the doctor notes that she has a temperature of 39°C, red fauces, cervical lymphadenopathy, and a slightly palpable spleen. What investigation would be most suitable for this patient?
Your Answer: Blood cultures
Correct Answer: Monospot test
Explanation:Diagnosis of Glandular Fever with Monospot Test
Glandular fever, caused by the Epstein-Barr virus, is suspected in a young girl based on her atypical lymphocytes in a full blood count. To confirm the diagnosis, a Monospot test is used. This test detects heterophile antibodies that are produced in response to an EBV infection. The antibodies are directed against horse red blood cells, and their presence in the blood indicates an active EBV infection. The Monospot test is a quick and reliable way to diagnose glandular fever, allowing for prompt treatment and management of symptoms.
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This question is part of the following fields:
- Infectious Diseases
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Question 30
Correct
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A 23-year-old man gets into a brawl outside a nightclub and is stabbed in the back, on the left side, about 3 cm below the 12th rib in the mid scapular line. Which structure is most likely to be injured first as a result of this incident?
Your Answer: Left kidney
Explanation:The most probable structure to be injured is the left kidney, which is situated in this area. The left adrenal and ureter are unlikely to be injured alone, while the spleen is located higher up.
Anatomical Planes and Levels in the Human Body
The human body can be divided into different planes and levels to aid in anatomical study and medical procedures. One such plane is the transpyloric plane, which runs horizontally through the body of L1 and intersects with various organs such as the pylorus of the stomach, left kidney hilum, and duodenojejunal flexure. Another way to identify planes is by using common level landmarks, such as the inferior mesenteric artery at L3 or the formation of the IVC at L5.
In addition to planes and levels, there are also diaphragm apertures located at specific levels in the body. These include the vena cava at T8, the esophagus at T10, and the aortic hiatus at T12. By understanding these planes, levels, and apertures, medical professionals can better navigate the human body during procedures and accurately diagnose and treat various conditions.
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This question is part of the following fields:
- Neurological System
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