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Question 1
Incorrect
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Regarding local anaesthetics, which of the following statements is INCORRECT:
Your Answer: Bupivacaine takes up to 30 minutes for a full effect.
Correct Answer: Adrenaline should be used in digital nerve blocks to create a bloodless field.
Explanation:It is not advisable to give adrenaline/epinephrine with a local anaesthetic injection in digits or appendages because of the risk of ischaemic necrosis.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 2
Incorrect
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C3 deficiency leads to particular susceptibility of infection with which of the following:
Your Answer: Intracellular bacteria
Correct Answer: Encapsulated bacteria
Explanation:Macrophages and neutrophils have C3b receptors and they phagocytose C3b-coated cells. C3 deficiency thus leads to increased susceptibility of infection with encapsulated organisms (e.g. S. pneumoniae, H. influenzae).The early stages of the complement cascade leading to coating of the cells with C3b can occur by two different pathways:The classical pathway usually activated by IgG or IgM coating of cellsThe alternative pathway which is more rapid and activated by IgA, endotoxin and other factors
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This question is part of the following fields:
- Immune Responses
- Pathology
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Question 3
Correct
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Which of the following is NOT an adverse effect associated with warfarin therapy:
Your Answer: Neutropenia
Explanation:Adverse effects of warfarin:The most common adverse effect of warfarin is bleedingOther common adverse effects of warfarin include nausea, vomiting, diarrhoea, jaundice, hepatic dysfunction, pancreatitis, pyrexia, alopecia, purpura, and rashSkin necrosis is a rare but serious adverse effect of warfarin; treatment with warfarin should be stopped if warfarin related skin necrosis is suspectedCalciphylaxis is a rare, but a very serious condition that causes vascular calcification and cutaneous necrosis
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 4
Correct
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A 60-year-old man presents with marked breathlessness. He has with a history of ischaemic heart disease. On examination, there is coarse bibasal crackles, marked peripheral oedema and chest X-ray taken is consistent with severe pulmonary oedema. RR is 28 per minute. Which receptor is responsible for detecting pulmonary oedema and the subsequent increase in respiratory rate?
Your Answer: Juxtacapillary receptors
Explanation:Pulmonary oedema causes stimulation of the Juxtacapillary receptors (J receptors) leading to a reflex increase in breathing rate. These receptors are also thought to be involved in the sensation of dyspnoea. The J receptors are sensory cells and are located within the alveolar walls in juxtaposition to the pulmonary capillaries.Aortic baroreceptor are involved in detecting blood pressureCentral chemoreceptors detect changes in CO2 and hydrogen ion within the brainAtrial volume receptors regulate plasma volume
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 5
Correct
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A 35-year-old woman has complaints of nausea, abdominal pain and dark urine. On examination, you notice she has jaundice. She tells you she recently started a new medication.Which drug is NOT likely to cause cholestatic jaundice out of the following?
Your Answer: Isoniazid
Explanation:Isoniazid is an antibiotic used in the treatment of tuberculosis. It can cause acute, dose-dependent, hepatitis but is not a recognised cause of cholestatic jaundice.The drugs that cause cholestatic jaundice are the following:1. Nitrofurantoin2. Erythromycin3. Cephalosporins4. Verapamil5. NSAIDs6. ACE inhibitors7. Tricyclic antidepressants8. Phenytoin9. Azathioprine10. Carbamazepine11. Oral contraceptive pills12. Diazepam13. Ketoconazole14. Tamoxifen
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 6
Correct
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An 8-year-old boy was brought to the emergency room with complaints of a rash and fever that have been present for the past 3 days. Upon history taking and observation, it was noted that the rash started behind the ears and then spread to the face and body. The presence of coryzal symptoms, dry cough, and conjunctivitis was also observed.What is most likely the diagnosis of the case presented above?
Your Answer: Measles
Explanation:The measles virus is an enveloped virus classified in the genusMorbillivirus.Measles is highly contagious and spreads by aerosol. Initial replication takes place in the mucosal cells of the respiratory tract; measles virus then replicates in the local lymph nodes and spreads systemically. The virus circulates in the T and B cells and monocytes, until eventually the lungs, gut, bile duct, bladder, skin, and lymphatic organs are involved. After an incubation period of 7 to 10 days, there is an abrupt onset, with symptoms of sneezing, runny nose and cough, red eyes, and rapidly rising fever. About 2 to 3 days later, a maculopapular rash appears on the head and trunk. Koplik spots, lesions on the oral mucosa consisting of irregular red spots, with a bluish white speck in the centre, generally appear 2 to 3 days before the rash and are diagnostic.Measles is easily diagnosed clinically, so few requests for laboratory identification are made. The virus is fragile and must be handled carefully. The specimens of choice are from the nasopharynx and urine, but the virus can only be recovered from these sources in the early stages of infection. The virus grows on PMK cells, causing the formation of distinctive spindle-shaped or multinucleated cells.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 7
Incorrect
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Regarding bile, which of the following statements is INCORRECT:
Your Answer: The bile acid-independent fraction of bile is made at the time it is required.
Correct Answer: The sphincter of Oddi contracts to force bile from the gallbladder into the duodenum.
Explanation:Bile is secreted by hepatocytes. It is isotonic and resembles plasma ionically. This fraction of bile is called the bile acid-dependent fraction. As it passes along the bile duct, the bile is modified by epithelial cells lining the duct by the addition of water and bicarbonate ions; this fraction is called the bile acid-independent fraction. Overall, the liver can produce 500 – 1000 mL of bile per day. The bile is either discharged directly into the duodenum or stored in the gallbladder. The bile acid-independent fraction is made at the time it is required i.e. during digestion of chyme. The bile acid-dependent fraction is made when the bile salts are returned from the GI tract to the liver, and is then stored in the gallbladder until needed. The gallbladder not only stores bile but concentrates it by removing non-essential solutes and water, leaving bile acids and pigments, mainly by active transport of Na+into the intercellular spaces of the lining cells which, in turn, draws in water, HCO3-and Cl-from the bile and into the extracellular fluid. Within a few minutes of a meal, particularly when fatty foods have been consumed, the gallbladder contracts and releases bile into the bile duct. The sphincter of Oddi is relaxed, allowing the bile to pass into the duodenum through the ampulla of Vater.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 8
Incorrect
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A patient with a diagnosis of HIV presents with a fever, sore throat, and general malaise and you are concerned the patient may have an AIDS defining illness.Which one of these, according to the CDC definition, would mean a patient infected with HIV has AIDS?
Your Answer: A positive p24 antigen test
Correct Answer: CD4 T-cell percentage of total lymphocytes of less than 15%
Explanation:According to the CDC definition, a patient co-infected with HIV can be diagnosed with AIDS if he or she has:A CD4 T-cell count of less than 200 cells/mm3 or;A CD4 T-cell percentage of total lymphocytes of less than 15% or;An AIDS defining infectionA Streptococcal throat infection is not an AIDS defining infection.A normal CD4 count ranges from 500-1000 cells/mm3. A CD4 (not CD8) count of less than 200 cells/mm3 is AIDS defining.The CD4 count can vary from day to day and depending upon the time that the blood test is taken. It can also be affected by the presence of other infections or illnesses. Treatment with anti-retroviral therapy should be considered at CD4 count of less than 350 cells/mm3.Serum concentrations of the p24 antigen (the viral protein that makes up most of the core of the HIV) are usually high in the first few weeks after human immunodeficiency virus (HIV) infection and testing for p24 antigen is therefore a useful way of diagnosing very early infection.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 9
Incorrect
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You examine a 50-year-old female who has a swollen, painful right big toe. She has a history of gout, and this discomfort is identical to prior relapses, according to her. She is currently taking 200 mg of allopurinol per day and has been for the last year. This is her second round of acute gout within this time period. She has no prior medical history to speak of and does not take any other medications. She doesn't have any known drug allergies.Which of the following management options is the SINGLE MOST APPROPRIATE?Â
Your Answer: Increase the dose of allopurinol to 300 mg per day
Correct Answer: Continue with the allopurinol and commence naproxen
Explanation:Allopurinol should not be started during an acute gout episode because it can both prolong and trigger another acute attack. Allopurinol should be continued in patients who are currently taking it, and acute attacks should be treated as usual with NSAIDs or colchicine, as needed.Non-steroidal anti-inflammatory medications (NSAIDs), such as naproxen, are the first-line treatment for acute gout attacks. Colchicine can be used in situations where NSAIDs are contraindicated, such as in patients with hypertension or those who have had a history of peptic ulcer disease. Because there is no reason for this patient to avoid NSAIDs, naproxen would be the medicine of choice from the list above.It would be reasonable to titrate up the allopurinol dose once the acute episode has subsided, targeting <6 mg/dl (<360 µmol/l) plasma urate levels .Febuxostat (Uloric) is a drug that can be used instead of allopurinol to treat persistent gout.
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This question is part of the following fields:
- Musculoskeletal Pharmacology
- Pharmacology
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Question 10
Incorrect
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Regarding airway resistance, which of the following statements is INCORRECT:
Your Answer: Sympathetic stimulation and adrenaline cause bronchodilation mediated by beta2-adrenoceptors.
Correct Answer: In the lower respiratory tract, airway resistance is mostly determined by the smallest bronchioles.
Explanation:Airway resistance is primarily determined by the airway radius according to Poiseuille’s law, and whether the flow is laminar or turbulent. The major site of airway resistance is the medium-sized bronchi. The smallest airways would seem to offer the highest resistance, but they do not because of their branching parallel arrangement.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 11
Incorrect
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A 1-year-old male is brought to the paediatrician by his mother due to swelling of the right knee after a minor fall. On examination, the right knee is swollen, fluctuant and tender. Ultrasound-guided aspiration reveals a massive hemarthrosis. Family history shows that his older brother also has a bleeding disorder. Which one of the following conditions does the patient most likely have?
Your Answer: Von Willebrand disease
Correct Answer: Haemophilia A
Explanation:A diagnosis of Haemophilia is supported in this patient by the family history and the presence of hemarthrosis-both characteristics of Haemophilia. Haemophilia A is caused by Factor VIII deficiency, leading to impaired coagulation. This disease typically presents after six months when the child starts crawling. Von Willebrand disease presents with nosebleeds and hematomas. Idiopathic thrombocytopenic purpura presents with bruises that resemble a rash. Glucose-6-phosphate dehydrogenase (G6PD) deficiency presents with haemolytic anaemia induced by specific drugs or foods. Factor V Leiden mutation causes blood clotting rather than bleeding.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 12
Correct
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What is the approximate lifespan of the mature erythrocyte:
Your Answer: 120 days
Explanation:Erythrocytes have a normal lifespan of about 120 days. Mature erythrocytes are biconcave discs with no nucleus, ribosomes or mitochondria but with the ability to generate energy as ATP by the anaerobic glycolytic pathway. The red cell membrane consists of a bipolar lipid layer with a membrane skeleton of penetrating and integral proteins anchoring carbohydrate surface antigens. The shape and flexibility of red cells allows them to deform easily and pass through capillaries.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 13
Correct
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A 62-year-old woman presents with a 3-month history of lethargy and tiredness. She states that she has also felt very itchy, particularly after a hot bath and that she is often dizzy and sweaty. On examination she appears plethoric and you note the presence of splenomegaly. Her blood tests today show that her haemoglobin level is 16.9 g/dl.What is the most likely diagnosis in this case? Select ONE answer only.
Your Answer: Polycythaemia vera
Explanation:Polycythaemia vera (PCV), which is also referred to as polycythaemia rubra vera, is a clonal haematological malignancy in which the bone marrow produces too many red blood cells. It may also result in the overproduction of white blood cells and platelets. It is most commonly seen in the elderly and the mean age at diagnosis is 65-74 years.Patients can be completely asymptomatic and it is often discovered as an incidental finding on a routine blood count. Approximately 1/3 of patients present with symptoms due to thrombosis, of these 3/4 have arterial thrombosis and 1/4 venous thrombosis. Features include stroke, myocardial infarction, deep vein thrombosis and pulmonary embolism.The other clinical features of PCV include:Plethoric appearanceLethargy and tirednessSplenomegaly (common)Pruritis (in 40% – particularly after exposure to hot water)Headaches, dizziness and sweating (in 30%)Gouty arthritis (in 20%)Budd-Chiari syndrome (in 5-10%)Erythromyalgia (in 18.5 g/dl in men, 16.5 g/dl in womenElevated red cell mass > 25% above mean normal predicted valuePresence of JAK2 mutationMinor criteria:Bone marrow biopsy showing hypercellularity with prominent erythroid, granulocytic and megakaryocytic proliferationSerum erythropoietin level below normal rangeEndogenous erythroid colony formation in vitroThe main aim of treatment is to normalize the full blood count and prevent complications such as thrombosis. Venesection is the treatment of choice but hydroxyurea can also be used to help control thrombocytosis.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 14
Correct
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A well recognised adverse effect of metoclopramide is which of the following?
Your Answer: Acute dystonic reaction
Explanation:Side effects of metoclopramide are commonly associated with extrapyramidal effects and hyperprolactinemia. Therefore its use must be limited to short-term use. Metoclopramide can induce acute dystonic reactions which involve facial and skeletal muscle spasms and oculogyric crises. These dystonic effects are more common in the young girls and young women, and in the very old. These symptoms usually occur shortly after starting treatment with this drug and subside within 24 hours of stopping it. Abortion of dystonic attacks can be carried out by injection of an antiparkinsonian drug like procyclidine.
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 15
Correct
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A 12-year-old boy presents to the ED with symptoms suggesting an anaphylactic reaction.Which of these statements about anaphylaxis is true?
Your Answer: The immunoglobulin-antigen complex binds to Fc receptors on the surface of mast cells.
Explanation:Anaphylaxis is an example of a type I hypersensitivity reaction. It is IgE mediated. It requires a prior exposure to the antigen. The initial exposure sensitizes the body to the antigen and a second exposure to that antigen leads to an anaphylactic reaction.Massive calcium influx into the cells leads to mast cell degranulation. The Immunoglobulin antigen complex binds to Fc receptors on the surface of mast cells. The result is mast cell degranulation and release of histamine, proteoglycans and serum proteases from cytoplasmic granules.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 16
Correct
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Which of the following hormones is dysfunctional in diabetes insipidus:
Your Answer: Antidiuretic hormone
Explanation:Diabetes insipidus (DI) may result from a deficiency of ADH secretion (cranial DI) or from an inappropriate renal response to ADH (nephrogenic DI). As a result, fluid reabsorption at the kidneys is impaired, resulting in large amounts of hypotonic, dilute urine being passed with a profound unquenchable polydipsia.The biochemical hallmarks of DI are:High plasma osmolality (> 295 mOsm/kg)Low urine osmolality (< 300 mOsm/kg)Hypernatraemia (> 145 mmol/L)High urine volume
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 17
Correct
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A 20-year-old patient had sustained a supracondylar fracture due to falling from a skateboard. The frequency of acute nerve injuries accompanying supracondylar humeral fractures ranges from 10 to 20%. The most common complication is injury to which nerve?
Your Answer: Median nerve
Explanation:According to various studies, the frequency of acute nerve damage associated with supracondylar humeral fractures in children ranges from 10% to 20%. Median nerve injury and anterior interosseous nerve injury are the most common consequences. Damage to this nerve indicated weakening or abnormal extension of the index finger’s distal interphalangeal joint and the thumb’s interphalangeal joint. The absence of sensibility is a distinguishing attribute. A surgical neck humerus fracture may cause injury to the axillary nerve. A midshaft humerus fracture might cause injury to the radial nerve. A medial epicondylar fracture might cause injury to the ulnar nerve.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 18
Incorrect
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Atrial natriuretic peptide (ANP) is primarily produced in response to:
Your Answer: An decrease in central venous pressure (CVP)
Correct Answer: An increase in intravascular fluid volume
Explanation:Atrial natriuretic peptide (ANP) is released from cardiac atrial muscle cells in response to atrial stretch caused by an increase in intravascular fluid volume and is also produced in collecting duct cells.Atrial natriuretic peptide acts to inhibit sodium reabsorption in the distal nephron.
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This question is part of the following fields:
- Physiology
- Renal
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Question 19
Incorrect
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A 30-year-old man presents with diarrhoea, fever, vomiting, and abdominal cramps. A stool culture was ordered and showed growth of Salmonella spp.Among the following serotypes of Salmonella spp., which is considered to be the most common cause of salmonella gastroenteritis?
Your Answer: Serotype E
Correct Answer: Serotype D
Explanation:A common cause of gastroenteritis, Salmonella enteritidis, and Salmonella typhi, which causes enteric fever, are both group D. Therefore, serotype D Salmonella species are most commonly associated with gastroenteritis.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 20
Incorrect
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An arterial blood gas test is performed to a 25-year-old students who presents with confusion, headache, nausea and malaise. The results show that carbon monoxide levels are significantly high. Which of the following carbon monoxide poisoning assertions is true?
Your Answer: CO has no effect on oxygen transport
Correct Answer: The PO 2 of the blood in CO poisoning can be normal
Explanation:By combining with haemoglobin to form carboxyhaemoglobin, carbon monoxide (CO) disrupts the blood’s oxygen transport function. CO binds to haemoglobin with a 240-fold higher affinity than oxygen. As a result, even small amounts of CO can bind a large portion of the blood’s haemoglobin, making it unavailable for oxygen transport. During a suspected carbon monoxide poisoning, the blood PO2 and haemoglobin concentrations will be normal, but the oxygen concentration will be drastically reduced. The oxygen dissociation curve will also shift to the left in the presence of Carboxyhaemoglobin ( haemoglobin and carbon monoxide combination), interfering with oxygen unloading.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 21
Incorrect
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You are asked to review the blood results on a 56-year-old man who appears to be acutely unwell. His results show that he is neutropenic.Which ONE of the following is NOT a recognized cause of a neutropenia?
Your Answer: Carbimazole
Correct Answer: Hyposplenism
Explanation:Neutropenia is defined as a total neutrophil count of < 2.0 x 109/l.It can be caused by:Viral infectionsCollagen disease e.g. SLE and RAChemotherapy and radiotherapyHypersplenismMarrow infiltrationVitamin and folate deficiencyDrug reactionsDrugs that cause neutropenia include flecainide, phenytoin, carbimazole, indomethacin and co-trimoxazole.
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This question is part of the following fields:
- Haematology
- Pathology
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Question 22
Correct
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Regarding bronchiolitis, which of the following statements is CORRECT:
Your Answer: Chest x-ray may show hyperinflation and increased peribronchial markings.
Explanation:Acute bronchiolitis is caused most commonly by respiratory syncytial virus, occurring mostly in children aged 6 months to 2 years. Children with bronchiolitis are febrile and tachypnoeic with a dry cough and difficulty feeding. Examination may reveal chest hyperinflation, respiratory distress, wheezing and fine end-inspiratory crepitations. Chest x-ray may show hyperinflation and increased peribronchial markings (although CXR should only performed if there is diagnostic uncertainty or an atypical course). Treatment is usually supportive, aerosolized ribavirin is reserved for severely ill or immunocompromised patients.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 23
Correct
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Question 24
Correct
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Which of the following is NOT an indication for a H1 receptor antihistamine:
Your Answer: Gastroesophageal reflux disease
Explanation:Antihistamines are competitive inhibitors at the H1-receptor (in contrast to H2 receptor antagonists used to decrease gastric acid secretion in gastroesophageal reflux disease).Indications: Allergic rhinitis and conjunctivitisUrticarial rashes, pruritus, insect bites and stingsAngioedemaAnaphylaxis (second line adjunct to adrenaline)Nausea/vomiting and prevention of motion sicknessInsomnia
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 25
Incorrect
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A 70-year-old patient diagnosed with Cushing's syndrome, has a history of weight gain, hypertension, and easy bruising.Which of the following statements about Cushing's syndrome is NOTÂ true?Â
Your Answer: Acanthosis nigricans can occur
Correct Answer: Menorrhagia is a common feature
Explanation:Cushing’s syndrome is a group of symptoms and signs brought on by long-term exposure to high amounts of endogenous or exogenous glucocorticoids.Iatrogenic corticosteroid injection is the most prevalent cause of Cushing’s syndrome.Cortisol levels fluctuate throughout the day, with the greatest levels occurring around 0900 hours and the lowest occurring at 2400 hrs during sleep. The diurnal swing of cortisol levels is lost in Cushing’s syndrome, and levels are greater throughout the 24-hour period. In the morning, levels may be normal, but they may be high at night-time, when they are generally repressed.Insulin resistance causes hyperglycaemia, which is a frequent symptom. Insulin resistance can produce acanthosis nigricans in the axilla and around the neck, as well as other skin abnormalities.In contrast to menorrhagia, elevated testosterone levels are more likely to produce amenorrhoea or oligomenorrhoea. Infertility in women of reproductive age can also be caused by high androgen levels.A dexamethasone suppression test or a 24-hour urine free cortisol collection can both be used to establish the existence of Cushing’s syndrome.
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 26
Correct
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A 17-year-old student presents with a headache and petechial rash. A diagnosis of meningitis was suspected, with a causative agent of Neisseria meningitidis. Which of the following statements is considered correct regarding Neisseria meningitidis?
Your Answer: The antiphagocytic polysaccharide capsule is the main determinant of its pathogenicity
Explanation:N. meningitidis is a Gram-negative cocci and can be found as a commensal as well as an invasive pathogen. It is an important etiologic agent of endemic and epidemic meningitis and meningococcaemia and rarely pneumonia, purulent arthritis, or endophthalmitis. N. meningitidis has also been recovered from urogenital and rectal sites as a result of oral-genital contact. Meningococcal carriage, usually involving nonencapsulated strains, may cause an increase in protective antibody against the pathogenic strains. Of the 12 meningococcal encapsulated serogroups, A, B, C, Y, and W-135 account for most cases of disease in the world. N. meningitidis possesses a polysaccharide capsule that is antiphagocytic and serves as an important virulence factor.It can be found on the mucosal surfaces of the nasopharynx and oropharynx in 30% of the human population. The organism is transmitted by close contact with respiratory droplet secretions from a carrier to a new host. Only a few newly colonized hosts develop meningococcal disease, with the highest incidence being found in infants and adolescents.The quadrivalent vaccine Menactra is a polysaccharide-protein conjugated vaccine with antigens to serogroups A, C, Y, and W-135. This conjugate vaccine is licensed for people 2 to 55 years old. This vaccine does not protect against meningitis caused by serogroup B because group B polysaccharide is a very poor immunogen in humans.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 27
Incorrect
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About what percentage of patients with hepatitis A develop chronic infection:
Your Answer: 0.1
Correct Answer: None
Explanation:Chronic hepatitis and carrier state does not occur in hepatitis A infection and complete immunity is attained after infection.
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This question is part of the following fields:
- Microbiology
- Pathogens
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Question 28
Incorrect
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Vitamin D is a group of secosteroids that play a role in calcium and phosphate control. Vitamin D's hormonally active metabolite is 1,25-dihydroxycholecalciferol.Which enzyme hydroxylates 25-hydroxycholecalciferol to form 1,25-dihydroxycholecalciferol?Â
Your Answer: 25-hydroxylase
Correct Answer: 1-alpha-hydroxylase
Explanation:The hormone-active metabolite of vitamin D is 1,25-dihydroxycholecalciferol (commonly known as calcitriol). Its activities raise calcium and phosphate levels in the bloodstream.In the presence of UVB light, 7-dehydrocholesterol is converted to cholecalciferol in the epidermal layer of the skin, resulting in 1,25-dihydroxycholecalciferol.Cholecalciferol is then converted to 25-hydroxycholecalciferol in the endoplasmic reticulum of liver hepatocytes by 25-hydroxylase (calcifediol).Finally, 1-alpha-hydroxylase converts 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol in the kidney. The key regulatory point in the formation of 1,25-dihydroxycholecalciferol is 1-alpha-hydroxylase, which is induced by parathyroid hormone or hypophosphatemia.The following are the primary effects of 1,25-dihydroxycholecalciferol:Calcium and phosphate absorption in the small intestine is increased.Calcium reabsorption in the kidneys is increased.Increases phosphate reabsorption in the kidneys.Increases the action of osteoclastic bacteria (increasing calcium and phosphate resorption from bone)Inhibits the action of 1-alpha-hydroxylase in the kidneys (negative feedback)
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 29
Correct
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Despite taking the oral contraceptive pill, a 29-year-old woman becomes pregnant. During a medication review, you discover that she is epileptic and that her antiepileptic therapy has recently been changed.Which of the following antiepileptics is most likely to impair the oral contraceptive pill's effectiveness?
Your Answer: Carbamazepine
Explanation:The metabolism of ethinyl oestradiol and progestogens has been shown to be increased by enzyme-inducing antiepileptics. The oral contraceptive pill (OCP) is less effective in preventing pregnancy as a result of this increased breakdown.Antiepileptic drugs that induce enzymes include:CarbamazepinePhenytoinPhenobarbitalTopiramateAntiepileptics that do not induce enzymes are unlikely to affect contraception. Non-enzyme-inducing anticonvulsants include the following:ClonazepamGabapentinLevetiracetamPiracetamSodium valproate is a type of valproate that is used toLamotrigine is an antiepileptic drug that does not cause the production of enzymes. It does, however, require special consideration, unlike other non-enzyme-inducing antiepileptics. The OCP does not appear to affect epilepsy directly, but it does appear to lower lamotrigine levels in the blood. This could result in a loss of seizure control and the occurrence of seizures.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 30
Incorrect
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All of the following single clinical risk groups is considered eligible to receive the seasonal influenza vaccination, except:
Your Answer:
Correct Answer: Patients with hypertension
Explanation:The following is the list of all the health and age factors that are known to increase a person’s risk of getting serious complications from flu:- Adults 65 years and older- Children younger than 2 years old- Asthma- Neurological and neurodevelopmental conditions- Blood disorders (such as sickle cell disease)- Chronic lung disease (such as chronic obstructive pulmonary disease [COPD] and cystic fibrosis)- Endocrine disorders (such as diabetes mellitus)- Heart disease (such as congenital heart disease, congestive heart failure and coronary artery disease)- Kidney diseases- Liver disorders- Metabolic disorders (such as inherited metabolic disorders and mitochondrial disorders)- People who are obese with a body mass index [BMI] of 40 or higher- People younger than 19 years old on long-term aspirin- or salicylate-containing medications.- People with a weakened immune system due to disease (such as people with HIV or AIDS, or some cancers such as leukaemia) or medications (such as those receiving chemotherapy or radiation treatment for cancer, or persons with chronic conditions requiring chronic corticosteroids or other drugs that suppress the immune system)- People who have had a stroke- Pregnant people and people up to 2 weeks after the end of pregnancy- People who live in nursing homes and other long-term care facilities
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This question is part of the following fields:
- Microbiology
- Principles Of Microbiology
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SESSION STATS - PERFORMANCE PER SPECIALTY
