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Question 1
Correct
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How is measles primarily transmitted:
Your Answer: Respiratory droplet route
Explanation:Measles belongs to the paramyxoviridae group of viruses. The incubation period is 7-18 days (average 10) and it is spread by airborne or droplet transmission. The classical presentation is of a high fever with coryzal symptoms and photophobia with conjunctivitis often being present. The rash that is associated is a widespread erythematous maculopapular rash. Koplik spots are pathognomonic for measles, and are the presence of white lesions on the buccal mucosa.
Differential diagnoses would include:
Rubella
Roseola infantum (exanthem subitom)
Scarlet fever
Kawasaki disease
Erythema infectiosum (5thdisease)
Enterovirus
Infectious mononucleosis
Diagnosis can be confirmed by the following means:
Salivary swab for measles specific IgM
Serum sample for measles specific IgM
Salivary swab for RNA detection
Possible complications include:
Otitis media
Febrile convulsions
Pneumonia
Bronchiectasis
Diarrhoea
Meningitis
Encephalitis
Immunosuppression
Subacute sclerosing panencephalitis
Death -
This question is part of the following fields:
- Microbiology
- Pathogens
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Question 2
Incorrect
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Regarding penicillin antibiotics, which of the following statements is CORRECT:
Your Answer: Patients who only develop a rash or urticaria immediately after penicillin should not be noted as having a penicillin allergy.
Correct Answer: Patients with a history of atopy are at higher risk of hypersensitivity reactions.
Explanation:Allergic reactions to penicillins occur in 1 – 10% of exposed individuals; anaphylactic reactions occur in fewer than 0.05% of treated patients. Patients with a history of atopic allergy are at higher risk of anaphylactic reactions to penicillins. Patients with a history of anaphylaxis, urticaria, or rash immediately after penicillin use should not receive a penicillin or other beta-lactam antibiotics; about 0.5 – 6.5 % of penicillin-sensitive patients will also be allergic to the cephalosporins.
Patients with a history of a more minor rash (i.e. non-confluent, non-pruritic rash restricted to a small area of the body) or delayed reaction (rash occurring more than 72 hours after penicillin administration), may not be truly allergic and may be considered for penicillin or beta-lactam treatment in severe infection (although possibility of allergy should be borne in mind). Other beta-lactam antibiotics (including cephalosporins) can be used in these patients.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 3
Correct
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Regarding platelets, which of the following statements is CORRECT:
Your Answer: Platelets are produced in the bone marrow by fragmentation of the cytoplasm of megakaryocytes.
Explanation:Platelets are produced in the bone marrow by fragmentation of the cytoplasm of megakaryocytes, derived from the common myeloid progenitor cell. The time interval from differentiation of the human stem cell to the production of platelets averages 10 days. Thrombopoietin is the major regulator of platelet formation and 95% of this is produced by the liver. The normal platelet count is approximately 150 – 450 x 109/L and the normal platelet lifespan is 10 days. Under normal circumstances, about one-third of the marrow output of platelets may be trapped at any one time in the normal spleen.
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This question is part of the following fields:
- Basic Cellular
- Physiology
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Question 4
Correct
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For which of the following is micelle formation necessary to facilitate intestinal absorption?
Your Answer: Vitamin D
Explanation:The arrangement of micelles is such that hydrophobic lipid molecules lie in the centre, surrounded by hydrophilic bile acids that are arranged in the outer region. This arrangement allows the entry of micelles into the aqueous layers surrounding the microvilli. As a result, the products of fat digestion (fatty acids and monoglycerides), cholesterol and fat-soluble vitamins (such as vitamin D) can then diffuse passively into the enterocytes. The bile salts are left within the lumen of the gut where they are reabsorbed from the ileum or excreted in faeces.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 5
Correct
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Antidiuretic hormone (ADH) levels are found to be increased in a young lady with unexplained hyponatraemia.
Which of the following is a result of the release of ADH?Your Answer: Small volumes of concentrated urine
Explanation:ADH, or antidiuretic hormone, is a hormone that regulates water and electrolyte balance. It is released in response to a variety of events, the most important of which are higher plasma osmolality or lower blood pressure. ADH increases plasma volume and blood pressure via acting on the kidneys and peripheral vasculature.
ADH causes extensive vasoconstriction by acting on peripheral V1 Receptors.ADH binds to B2 Receptors in the terminal distal convoluted tubule and collecting duct of the kidney, increasing transcription and aquaporin insertion in the cells that line the lumen. Aquaporins are water channels that allow water to pass through the tubule and into the interstitial fluid via osmosis, lowering urine losses.
The permeability of the distal collecting duct (the section within the inner medulla) to urea is likewise increased by ADH. More urea travels out of the tubule and into the peritubular fluid, contributing to the counter current multiplier, which improves the Loop of Henle’s concentrating power.Overall, there is enhanced urea and water reabsorption in the presence of ADH, resulting in modest amounts of concentrated urine. There is minimal urea and water reabsorption in the absence of ADH, resulting in huge amounts of dilute urine.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 6
Correct
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Regarding the foetal oxygen-haemoglobin dissociation curve, which of the following statements is CORRECT:
Your Answer: The HbF dissociation curve lies to the left of that for HbA.
Explanation:Foetal haemoglobin (HbF) has a higher affinity for oxygen than adult haemoglobin (HbA) because it’s gamma chains bind 2,3-DPG less avidly than beta chains of HbA. The HbF dissociation curve lies to the left of that for HbA. In the placenta PCO2moves from the foetal to the maternal circulation, shifting the maternal curve further right and the foetal curve further left (the double Bohr effect). The higher affinity of HbF relative to HbA helps transfer oxygen from mother to foetus. Therefore even through blood returning from the placenta to the foetus in the umbilical vein has a PO2of only about 4 kPa, its saturation is 70%. Oxygen transport in the foetus is also helped by a high Hb of about 170 – 180 g/L.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 7
Correct
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All of the following statements are correct with regards to protection of the gastric mucosa except which of the following?
Your Answer: NSAIDs directly stimulate increased parietal cell acid production.
Explanation:Prostaglandin production, which usually inhibits acid secretion and increases mucus and bicarbonate secretion, is inhibited by NSAIDs.
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 8
Correct
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Regarding antihistamines, which of the following statements is CORRECT:
Your Answer: Elderly patients and children are more susceptible to side effects.
Explanation:Elderly patients and children are more susceptible to side effects. Antihistamines are competitive inhibitors at the H1-receptor. The newer antihistamines e.g. cetirizine cause less sedation and psychomotor impairment than the older antihistamines because they are much less lipid soluble and penetrate the blood brain barrier only to a slight extent. Antihistamines are used as a second line adjunct to adrenaline in anaphylaxis.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 9
Correct
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The risk of renal impairment in a patient on ACE inhibitor therapy is increased by concomitant treatment with which of the following drug classes:
Your Answer: NSAIDs
Explanation:Concomitant treatment with NSAIDs increases the risk of renal damage, and with potassium-sparing diuretics (or potassium-containing salt substitutes) increases the risk of hyperkalaemia. Hyperkalaemia and other side effects of ACE inhibitors are more common in the elderly and in those with impaired renal function and the dose may need to be reduced.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 10
Correct
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A patient suffers a stab wound to the neck. The entry point of the blade is situated within the posterior triangle of the neck.
Which of the following muscles is most likely to be involved? Select ONE answer only.Your Answer: Anterior scalene
Explanation:The anterior triangle is the triangular area of the neck found anteriorly to the sternocleidomastoid muscle. It is formed by the anterior border of sternocleidomastoid laterally, the median line of the neck medially and by the inferior border of the mandible superiorly. The apex of the anterior triangle extends towards the manubrium sterni. The anterior triangle contains:
Muscles: thyrohyoid, sternothyroid, sternohyoid muscles
Organs: thyroid gland, parathyroid glands, larynx, trachea, esophagus, submandibular gland, caudal part of the parotid gland
Arteries: superior and inferior thyroid, common carotid, external carotid, internal carotid artery (and sinus), facial, submental, lingual arteries
Veins: anterior jugular veins, internal jugular, common facial, lingual, superior thyroid, middle thyroid veins, facial vein, submental vein, lingual veins
Nerves: vagus nerve (CN X), hypoglossal nerve (CN XII), part of sympathetic trunk, mylohyoid nerveThe posterior triangle is a triangular area found posteriorly to the sternocleidomastoid muscle. It has three borders; anterior, posterior and inferior borders. The anterior border is the posterior margin of the sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle, while the inferior border is the middle one-third of the clavicle. The investing layer of deep cervical fascia and integument forms the roof of the space, while the floor is covered with the prevertebral fascia along with levator scapulae, splenius capitis and the scalene muscles. The inferior belly of omohyoid subdivides the posterior triangle into a small supraclavicular, and a large occipital, triangle.
Contents:
Vessels: the third part of the subclavian artery, suprascapular and transverse cervical branches of the thyrocervical trunk, external jugular vein, lymph nodes
Nerves: accessory nerve (CN XI), the trunks of the brachial plexus, fibers of the cervical plexus
Of the muscles listed in the options, only the anterior scalene is situated within the posterior triangle of the neck. -
This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 11
Correct
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When the breast cancer of a 60-year old patient metastasizes and compresses the intervertebral foramina between the fourth and fifth cervical vertebrae, as well as the fourth and fifth thoracic vertebrae, this causes back pain. Which pair of nerves is most likely affected?
Your Answer: Fifth cervical and fourth thoracic nerves
Explanation:The fifth cervical nerve passes between the fourth and fifth cervical vertebrae, and the fourth thoracic nerve passes between the fourth and fifth thoracic vertebrae. Therefore, when the cancer metastasizes in this area, they are most likely affected.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 12
Correct
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An analytical study is conducted to compare the risk of stroke between Ticagrelor therapy and Warfarin therapy among patients with atrial fibrillation. The following is obtained from the study:
No. of patients who took Ticagrelor: 300
No. of patients who took Ticagrelor and suffered a stroke: 30
No. of patients who took Warfarin: 500
No. of patients who took Warfarin and suffered a stroke: 20
Compute for the absolute risk reduction of a stroke, with Warfarin as the standard of treatment.Your Answer: -0.06
Explanation:Absolute risk reduction (ARR) is computed as the difference between the absolute risk in the control group (ARC) and the absolute risk in the treatment group (ART).
Since Warfarin is the standard of treatment, Warfarin is considered as the control group.
ARR = ARC-ART
ARR = (20/500) – (30/300)
ARR = -0.06This means that there is increased risk of stroke in the treatment group, which is the Ticagrelor group.
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This question is part of the following fields:
- Evidence Based Medicine
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Question 13
Correct
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A 20-year-old male who is a known patient of sickle cell disease presents to the Emergency Room with a sustained erection that is extremely painful.
Out of the following clinical syndromes, which one does this patient most likely have?Your Answer: Priapism
Explanation:Sickling of red blood cells can lead to several different clinical syndromes. If the sickling occurs in the corpora cavernosa, it can lead to a sustained, painful erection of the penis, referred to as priapism. One of the complications is long-term impotence. It is important to seek a urological opinion immediately in this case, but in the interim, treat with perineal ice packs and walk up and down the stairs.
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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 52-year-old woman visits her local pharmacy to get medication to help with mild dyspepsia symptoms. The pharmacist on duty suggests she uses an over-the-counter antacid. She purchases an antacid that contains magnesium carbonate, which relieves her symptoms, but she unfortunately also develops a side effect.
Out of the following, which side effect is she MOST likely to develop after using the antacid?Your Answer: Diarrhoea
Explanation:Magnesium carbonate is an over the counter antacid commonly used to relieve symptoms in ulcer dyspepsia and non-erosive gastro-oesophageal reflux.
Antacids containing magnesium also tend to work as a laxative, while the antacids with aluminium may cause constipation. There is no significant increased risk of anaphylaxis, hepatotoxicity or renal impairment.
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This question is part of the following fields:
- Gastrointestinal Pharmacology
- Pharmacology
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Question 15
Incorrect
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A 23-year-old female has been prescribed a medication in the first trimester of pregnancy due to a life-threatening medical problem. After delivery, the foetus is found to have nasal hypoplasia, stippling of his bones and atrophy of bilateral optic discs along with growth retardation.
Which ONE of the following drugs has this woman most likely received?Your Answer: Ibuprofen
Correct Answer: Warfarin
Explanation:Warfarin is teratogenic and can cause a host of abnormalities in the growing foetus. These include hypoplasia of the nasal bridge, stippling of the epiphyses, multiple ophthalmic complications, growth retardation, pectus carinatum, atrial septal defect, ventriculomegaly and a patent ductus arteriosus.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 16
Incorrect
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Which of the following is caused by an alpha-1 antitrypsin deficiency?
Your Answer: Cystic fibrosis
Correct Answer: Early onset emphysema
Explanation:Mucus contains chemicals such as alpha-1-antitrypsin, lysozyme, and IgA that protect the airway from pathogens and damaging proteases released from dead bacteria and immune cells. Early-onset emphysema results from a genetic deficit of alpha-1-antitrypsin, which is caused by unregulated protease activity in the lungs, which results in the degradation of elastin in the alveoli.
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This question is part of the following fields:
- Physiology
- Respiratory
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Question 17
Incorrect
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The following statements concerning lung compliance is true EXCEPT?
Your Answer: Lung compliance comprises static and dynamic lung compliance
Correct Answer: Lung compliance is described by the equation: C = ∆ P/ ∆V, where C = compliance, P = pressure, and V = volume
Explanation:Lung compliance is the change in volume per unit change in distending pressure.
It is calculated using the equation:
Lung compliance = ΔV / ΔP
Where:
ΔV is the change in volume
ΔP is the change in pleural pressure.Lung compliance is inversely proportional to stiffness and elastance.
It comprises static (no airflow) and dynamic (during continuous breathing) components.
It is the slope of the pressure-volume curve.
Lung compliance describes the distensibility of the lungs and the chest wall.
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This question is part of the following fields:
- Physiology
- Respiratory Physiology
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Question 18
Incorrect
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Which law describes the rate of diffusion in a solution?
Your Answer: Darcy’s law
Correct Answer: Fick’s law
Explanation:Fick’s law describes the rate of diffusion in a solution. Fick’s law states that:
Jx = -D A (ΔC / Δx)
Where:
Jx = The amount of substance transferred per unit time
D = Diffusion coefficient of that particular substance
A = Surface area over which diffusion occurs
ΔC = Concentration difference across the membrane
Δx = Distance over which diffusion occurs
The negative sign reflects movement down the concentration gradient -
This question is part of the following fields:
- Basic Cellular Physiology
- Physiology
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Question 19
Correct
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A 39-year-old man who is suffering from a bacterial infection require antibiotic treatment. You need to figure out which antibiotic is most suitable. Listed below are antimicrobial drugs.
Which one is a nucleic acid synthesis inhibitor?
Your Answer: Ciprofloxacin
Explanation:Ciprofloxacin and other quinolone antibiotics work by blocking DNA gyrase, an enzyme that compresses bacterial DNA into supercoils, as well as a type II topoisomerase, which is required for bacterial DNA separation. As a result, they prevent nucleic acid synthesis.
The following is a summary of the many modes of action of various types of antimicrobial agents:Action Mechanisms-Â Examples:
Cell wall production is inhibited
Vancomycin
Vancomycin
CephalosporinsThe function of the cell membrane is disrupted
Nystatin
Polymyxins
Amphotericin BÂInhibition of protein synthesis
Chloramphenicol
Macrolides
Aminoglycosides
TetracyclinesNucleic acid synthesis inhibition
Quinolones
Trimethoprim
Rifampicin
5-nitroimidazoles
Sulphonamides
Anti-metabolic activity
Isoniazid -
This question is part of the following fields:
- Infections
- Pharmacology
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Question 20
Incorrect
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A 6-year-old female is brought to the Ophthalmology Clinic by her mother with the complaint of itching, redness, and a watery discharge of the right eye. Past medical history revealed an upper respiratory tract infection one week ago.
On examination of the right eye, there is mild erythema of the palpebral conjunctiva and visible follicles seen on eversion of the eyelid, lid oedema, and subconjunctival petechial haemorrhages. The discharge is watery and not purulent.
You diagnose her with viral conjunctivitis. According to the current NICE guidelines, which ONE of the following management options would NOT be included for this patient?Your Answer: Lubricating drops can be prescribed to help manage her symptoms
Correct Answer: The child should be excluded from school until the infection has resolved
Explanation:The NICE guidelines do NOT recommend isolating a patient with viral conjunctivitis from others or skipping school or work. The disease is contagious, but the spread of the disease can be controlled by maintaining good hygiene practices such as:
1. frequent hand washing
2. use of separate flannels and towels
3. Avoid close contact with othersAntibiotic prescriptions are not part of the NICE guidelines for viral conjunctivitis as they will not affect the course of the disease. Most cases of viral conjunctivitis are self-limiting and resolve within one to two weeks.
The NICE guidelines recommend that symptoms may be eased with self-care measures such as:
1. Bathing/cleaning the eyelids with cotton wool soaked in sterile saline or boiled and cooled water to remove any discharge
2. Cool compresses applied gently around the eye area
3. Use of lubricating drops or artificial tears -
This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 21
Incorrect
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A 42-year-old woman presents with face swelling prominently affecting her upper lip and hands. She has previously been diagnosed with hereditary angioedema.
Which of these is the most appropriate management option for this acute attack?Your Answer: IV hydrocortisone
Correct Answer: Fresh frozen plasma
Explanation:Hereditary angioedema is inherited as an autosomal dominant disorder and is caused by deficiency of C1 esterase inhibitor, a protein that forms part of the complement system.
Attacks can be precipitated by stress and minor surgical procedures. Clinical features of hereditary angioedema include oedema of the skin and mucous membranes commonly affecting the face, tongue and extremities.
Angioedema and anaphylaxis due to a deficiency of C1 esterase inhibitor are resistant to adrenaline, steroids and antihistamines. Treatment is with fresh frozen plasma or C1 esterase inhibitor concentrate, which contains C1 esterase inhibitor.
Short-term prophylaxis for events that may precipitate angioedema attack is achieved with C1 esterase inhibitor or fresh frozen plasma infusions before the event while long-term prophylaxis can be achieved with antifibrinolytic drugs (tranexamic acid) or androgenic steroids.
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This question is part of the following fields:
- Pharmacology
- Respiratory Pharmacology
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Question 22
Incorrect
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Regarding the management of gout, which of the following statements is CORRECT:
Your Answer: Ibuprofen is the NSAID of choice in treating acute gout.
Correct Answer: Allopurinol may cause an acute attack of gout when first started.
Explanation:Allopurinol is a treatment for the prevention of gout. The initiation of treatment may precipitate an acute attack, and should be covered with an NSAID or colchicine, continued for at least one month after the hyperuricaemia has been corrected. Colchicine is not indicated for long term prevention of gout. NSAIDs are first line for acute gout; colchicine is an alternative in whom NSAIDs are contraindicated, not tolerated or ineffective (including in people taking anticoagulants). Ibuprofen is not recommended for acute gout, given it has only weak anti-inflammatory properties; naproxen, diclofenac or indometacin are indicated instead.
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This question is part of the following fields:
- Musculoskeletal
- Pharmacology
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Question 23
Incorrect
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Angiotensin II is part of the RAAS system. One of its effects is the constriction of efferent arterioles. Which of the following best describes the effect of angiotensin II- mediated constriction of efferent arterioles?
Your Answer: Decreased renal plasma flow, increased filtration fraction, decreased GFR
Correct Answer: Decreased renal plasma flow, increased filtration fraction, increased GFR
Explanation:The Renin-Angiotensin-Aldosterone System (RAAS) is a hormone system composed of renin, angiotensin, and aldosterone. Those hormones are essential for the regulation of blood pressure and fluid balance.
Cases of hypotension, sympathetic stimulation, or hyponatremia can activate the Renin-angiotensin-aldosterone system (RAAS). The following process will then increase the blood volume and blood pressure as a response.
When renin is released it will convert the circulating angiotensinogen to angiotensin I. The ACE or angiotensin-converting enzyme will then catalyst its conversion to angiotensin II, which is a potent vasoconstrictor. Angiotensin II can constrict the vascular smooth muscles and the efferent arteriole of the glomerulus.
The efferent arteriole is a blood vessel that delivers blood away from the capillaries of the kidney. The angiotensin II-mediated constriction of efferent arterioles increases GFR, reduces renal blood flow and peritubular capillary hydrostatic pressure, and increases peritubular colloid osmotic pressure, as a response to its action of increasing the filtration fraction.
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 24
Correct
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Regarding the renin-angiotensin-aldosterone system (RAAS), which of the following statements is CORRECT:
Your Answer: Angiotensin II has a predominant vasoconstrictor effect on the efferent arteriole.
Explanation:Angiotensin II constricts both the afferent and efferent arterioles, but preferentially increases efferent resistance. The net effect of the more prominent increase in efferent tone is that the intraglomerular pressure is stable or increased, thereby tending to maintain or even raise the GFR. Renin is produced by granular cells of the juxtaglomerular apparatus. Renin cleaves plasma angiotensinogen (produced in the liver) into angiotensin I. Angiotensin I is converted by angiotensin-converting enzyme (ACE) on pulmonary endothelial cells to angiotensin II. Angiotensin II acts to potentiate sympathetic activity (positive feedback).
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This question is part of the following fields:
- Physiology
- Renal
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Question 25
Incorrect
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Regarding a case-control study, which of the following statements is INCORRECT:
Your Answer: It is retrospective.
Correct Answer: The usual outcome measure is the relative risk.
Explanation:A case-control study is a longitudinal, retrospective, observational study which investigates the relationship between a risk factor and one or more outcomes. This is done by selecting patients who already have a specific disease (cases), matching them to patients who do not (controls) and then collecting data from the patients to compare past exposure to a possible risk factor. The usual outcome measure is the odds ratio.
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This question is part of the following fields:
- Evidence Based Medicine
- Study Methodology
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Question 26
Correct
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A 67-year-old female is admitted under your care with the complaint of shortness of breath and massive pedal oedema. There are fine crepitations up to the mid zones on both lung fields on chest auscultation. When questioned about her medication, she doesn't remember everything she takes but knows that there is a tablet to get rid of excess water.
Out of the following medications, which one increases the osmolality of the filtrate in the glomerulus and the tubule, creating an osmotic effect?Your Answer: Mannitol
Explanation:Mannitol is an osmotic diuretic that stops the absorption of water throughout the tubule, thus increasing the osmolality of both glomerular and tubular fluid. It is used to:
1. decrease intraocular pressure in glaucoma
2. decrease intracerebral pressure
3. oliguria.Furosemide is a loop diuretic that inhibits the Na/K/2Cl transported in the ascending limb of the Loop of Henle.
Bendroflumethiazide is a thiazide diuretic which inhibits the Na/Cl transporter.
Spironolactone is a potassium-sparing diuretic that acts as an aldosterone receptor antagonist.
Acetazolamide is a carbonic anhydrase inhibitor.
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This question is part of the following fields:
- Cardiovascular Pharmacology
- Pharmacology
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Question 27
Correct
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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?Your 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) -
This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 28
Correct
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Discontinuous capillaries are typically found where in the body:
Your Answer: Reticuloendothelial system
Explanation:Discontinuous capillaries, found in the reticuloendothelial system (bone marrow, liver and spleen), have large gaps between endothelial cells and are permeable to red blood cells.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 29
Incorrect
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A 63 year old lady presents to ED with a persistent cough and red currant jelly sputum. She has a history of chronic alcohol abuse and has an X-ray which demonstrates a cavitating pneumonia. The most likely causative pathogen is:
Your Answer: Haemophilus influenzae
Correct Answer: Klebsiella pneumoniae
Explanation:One of the results of Klebsiella pneumoniae is pneumonia that is usually a very severe infection. It is characterised by thick, bloody sputum (red currant jelly sputum), and is associated with complications like lung abscess, cavitation, necrosis, empyema and pleural effusions.
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This question is part of the following fields:
- Infections
- Microbiology
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Question 30
Correct
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A 5-year-old girl is brought into the Paediatric ER for acute seizures. She has been convulsing for the past 18 minutes now and was already two doses of lorazepam in the ambulance. Now, you prepare a phenytoin infusion to abolish the seizures.
According to the APLS algorithm, what dose of phenytoin is advised for a convulsing child at this stage?Your Answer: 20 mg/kg over 20 minutes
Explanation:Advanced paediatric life support (APLS) recommends phenytoin as the first choice for second-line anticonvulsant in a patient that continues to seize ten minutes after the second dose of the first-line anticonvulsant (benzodiazepine). (step 3 of the APLS algorithm)
The recommended dose of phenytoin infusion is up at 20 mg/kg over 20 minutes. If the patient has already taken phenytoin as maintenance therapy or is allergic to phenytoin, then a phenobarbitone infusion should be set up at 20 mg/kg over 30-60 minutes.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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SESSION STATS - PERFORMANCE PER SPECIALTY
