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Question 1
Correct
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A patient is sent in to ED by her GP with hyponatraemia and hyperkalaemia. There is most likely to be a deficiency in which of the following hormones:
Your Answer: Aldosterone
Explanation:A deficiency of aldosterone, as seen in adrenal insufficiency, can result in hyponatraemia and hyperkalaemia.
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This question is part of the following fields:
- Endocrine
- Physiology
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Question 2
Correct
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Thyroid cancer has spread to the regional lymph nodes of a patient as seen in a staging CT scan. The lymph from the thyroid gland will drain directly to which of the following nodes?
Your Answer: Deep lateral cervical lymph nodes
Explanation:Lymphatic drainage of the thyroid gland involves the lower deep cervical, prelaryngeal, pretracheal, and paratracheal nodes. The paratracheal and lower deep cervical nodes, specifically, receive lymphatic drainage from the isthmus and the inferior lateral lobes. The superior portions of the thyroid gland drain into the superior pretracheal and cervical nodes.
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This question is part of the following fields:
- Anatomy
- Head And Neck
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Question 3
Incorrect
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Polyuria and polydipsia develop in a patient with a history of affective disorders illness who has been on long-term lithium. She has a fluid deprivation test because she is suspected of having nephrogenic diabetic insipidus.Which of the following urine osmolality findings would be the most reliable in confirming the diagnosis?
Your Answer: After fluid deprivation >300 mosmol/kg, after IM desmopressin <300 mosmol/kg
Correct Answer: After fluid deprivation <300 mosmol/kg, after IM desmopressin <300 mosmol/kg
Explanation:The inability to produce concentrated urine is a symptom of diabetes insipidus. Excessive thirst, polyuria, and polydipsia are all symptoms of this condition. There are two forms of diabetes insipidus: Nephrogenic diabetes insipidus and cranial (central) diabetes insipidus.A lack of ADH causes cranial diabetic insipidus. Patients with cranial diabetes insipidus can have a urine output of up to 10-15 litres per 24 hours, however most patients can maintain normonatraemia with proper fluid consumption. Thirty percent of cases are idiopathic, while another thirty percent are caused by head injuries. Neurosurgery, brain tumours, meningitis, granulomatous disease (e.g. sarcoidosis), and medicines like naloxone and phenytoin are among the other reasons. There is also a very rare hereditary type that is linked to diabetes, optic atrophy, nerve deafness, and bladder atonia.Renal resistance to the action of ADH causes nephrogenic diabetes insipidus. Urine output is significantly increased, as it is in cranial diabetes insipidus. Secondary polydipsia can keep serum sodium levels stable or raise them. Chronic renal dysfunction, metabolic diseases (e.g., hypercalcaemia and hypokalaemia), and medications, such as long-term lithium use and demeclocycline, are all causes of nephrogenic diabetes insipidus.The best test to establish if a patient has diabetes insipidus vs another cause of polydipsia is the water deprivation test, commonly known as the fluid deprivation test. It also aids in the distinction between cranial and nephrogenic diabetes insipidus. Weight, urine volume, urine osmolality, and serum osmolality are all measured after patients are denied water for up to 8 hours. At the end of the 8-hour period, 2 micrograms of IM desmopressin is given, and measures are taken again at 16 hours.The following are the way results are interpreted:Urine osmolality after fluid deprivation : Urine osmolality after IM desmopressinCranial diabetes insipidus800 mosmol/kgNephrogenic diabetes insipidus<300 mosmol/kg : 800 mosmol/kg : >800 mosmol/kg
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This question is part of the following fields:
- Physiology
- Renal Physiology
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Question 4
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 NOT true?
Your Answer: Diagnosis can be confirmed by a 24-hour urinary free cortisol collection
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 5
Correct
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Liquefactive necrosis is most commonly seen in which of the following conditions:
Your Answer: Ischaemic stroke
Explanation:Liquefactive necrosis results in the loss of all cellular structure and the formation of a soft, semi-solid mass. This is commonly seen in the brain after a cerebral infarction.
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This question is part of the following fields:
- Inflammatory Responses
- Pathology
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Question 6
Correct
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A suicidal patient had lacerated his wrist, which resulted in an ulnar nerve injury. Which of the following will confirm the presence of an ulnar nerve injury?
Your Answer: Claw hand appearance
Explanation:An ulnar injury may result in abnormal sensations in the little finger and ring finger, usually on the palm side, weakness, and loss of coordination of the fingers. A claw like deformity of the hand and wrist is present. Pain, numbness, decreased sensation, tingling, or burning sensation in the areas controlled by the nerve are also possible.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 7
Incorrect
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A 68-year-old man with multiple myeloma presents with complaints of abdominal pain and malaise. A series of blood tests is done and his calcium level is 2.96 mmol/l.What effect will this blood test result have on gastric secretions?
Your Answer: Inhibit the release of intrinsic factor
Correct Answer: Stimulate the release of gastrin
Explanation:Hypercalcaemia stimulates the release of gastrin from the G-cells in the pyloric antrum of the stomach, the duodenum and the pancreas.Gastrin is also released in response to:Stomach distensionVagal stimulationThe presence of amino acids.Gastrin release is inhibited by the presence of acid and somatostatin.
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 8
Incorrect
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Which of the following statements is correct about the extensor digitorum muscle?
Your Answer: It assists with abduction of the wrist joint
Correct Answer: It extends the medial four digits at the metacarpophalangeal joints
Explanation:Extensor digitorum is a long muscle located in the posterior compartment of the forearm. Together with the extensor carpi ulnaris and extensor digiti minimi, extensor carpi radialis longus and brevis as well as the brachioradialis, it belongs to the group of superficial extensors of the forearm. These muscles can be easily palpated in the lateral aspect of the posterior forearm, especially during the extension of hand when they are contracted.Extensor digitorum runs from the lateral epicondyle of humerus to the medial four phalanges of the hand. In this way, it generates the pull for the extension of the four medial fingers in their metacarpophalangeal and both interphalangeal joints. Extensor digitorum also participates in the extension of the wrist.Extensor digitorum is innervated by posterior interosseous nerve which is a continuation of a deep branch of radial nerve (root value C7 and C8).Extensor digitorum is vascularized by the branches of three different arteries: (1) posterior interosseous artery, (2) radial recurrent artery, and (3) anterior interosseous artery. Anterior and posterior interosseous arteries are the branches of the common interosseous artery that arises from the ulnar artery. The radial recurrent artery is a branch of the radial artery.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 9
Correct
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You are examining the lower limbs of a 54 year old man who presented after falling from a ladder at home. During your neurological assessment you note a weakness of hip flexion. Which of the following nerves is the most important for flexion of the thigh at the hip joint:
Your Answer: Femoral nerve
Explanation:Flexion of the thigh at the hip joint is produced by the sartorius, psoas major, iliacus and pectineus muscles, assisted by the rectus femoris muscle, all innervated by the femoral nerve (except for the psoas major, innervated by the anterior rami of L1 – 3).
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This question is part of the following fields:
- Anatomy
- Lower Limb
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Question 10
Correct
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Which of the following states that the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of each of the gases in the mixture:
Your Answer: Dalton's law
Explanation:Dalton’s law states that when two or more gases, which do not react chemically, are present in the same container, the total pressure is the sum of the partial pressures of each gas.
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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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In which of the following cases is intravenous phenytoin contraindicated?
Your Answer: Hepatic impairment
Correct Answer: Second degree heart block
Explanation:Phenytoin Contraindications include:HypersensitivitySinus bradycardiaSinoatrial blockSecond and third degree A-V blockAdams-Stokes syndromeConcurrent use with delavirdineHistory of prior acute hepatotoxicity attributable to phenytoin
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This question is part of the following fields:
- Central Nervous System
- Pharmacology
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Question 12
Correct
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What is the mechanism of action of captopril:
Your Answer: Angiotensin-converting enzyme inhibitor
Explanation:Captopril is an angiotensin-converting enzyme (ACE) inhibitor, which inhibits the conversion of angiotensin I to angiotensin II.
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This question is part of the following fields:
- Cardiovascular
- Pharmacology
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Question 13
Incorrect
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A patient with pronounced tremor, muscle contractions, muscle spasms, and slowness of movement is brought in by his family. He has a long history of mental health issues for which he is currently treated with a variety of medications.Which of the medications listed below is most likely to be the cause of these side effects?
Your Answer: Amitriptyline
Correct Answer: Haloperidol
Explanation:Acute dyskinesias and dystonic reactions, tardive dyskinesia (rhythmic, involuntary movements of the tongue, face, and jaw), Parkinsonism (tremor, bradykinesia, and rigidity), akinesia, akathisia, and neuroleptic malignant syndrome are all examples of extrapyramidal side effects. They are caused by dopamine depletion or blockade in the basal ganglia; this lack of dopamine frequently mimics idiopathic extrapyramidal pathologies.The first-generation antipsychotics, which are strong dopamine D2 receptor antagonists, are the drugs most commonly associated with extrapyramidal side effects. Haloperidol and fluphenazine are the two drugs in this class that are most commonly associated with extrapyramidal side effects. Extrapyramidal adverse effects are less common in second-generation antipsychotics (e.g., olanzapine) than in first-generation antipsychotics.Other drugs are linked to extrapyramidal symptoms as well, but at a lower rate. Some antidepressants, lithium, various anticonvulsants, antiemetics, and, in rare cases, oral contraceptive agents are among them.
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This question is part of the following fields:
- CNS Pharmacology
- Pharmacology
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Question 14
Incorrect
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Which of the following statements about propofol is TRUE:
Your Answer: If accidentally injected outside a vein it can cause tissue necrosis.
Correct Answer: Propofol has some antiemetic action.
Explanation:Propofol has some antiemetic properties. It’s for this reason that it’s used to treat postoperative nausea and vomiting. Propofol is mostly processed in the liver, with the kidneys excreting just around 1% of it unaltered. Propofol, unlike thiopental, does not produce tissue necrosis when it is extravasated. Propofol lowers intracranial pressure via lowering brain metabolic rate and cerebral blood flow. Propofol is thought to be safe for people with bronchial asthma and chronic obstructive pulmonary disease.
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This question is part of the following fields:
- Anaesthesia
- Pharmacology
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Question 15
Correct
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A patient has a cardiac output of 4.8 L/min and a heart rate of 80 bpm, therefore their stroke volume is:
Your Answer: 60 mL
Explanation:Cardiac output (CO) = Stroke volume (SV) x Heart rate (HR). Therefore SV = CO/HR = 4.8/80 = 0.06 L = 60 mL.
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This question is part of the following fields:
- Cardiovascular
- Physiology
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Question 16
Incorrect
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All of the following statements are correct regarding penicillin antibiotics except:
Your Answer: Penicillins inhibit bacterial cell wall synthesis.
Correct Answer: Penicillins are of no use in meningitis as they are unable to penetrate into the cerebrospinal fluid.
Explanation:Penicillin penetration into the cerebrospinal fluid is generally poor. However, when the meninges are inflamed, as in meningitis, penetration of penicillin is increased. Benzylpenicillin should be given before transfer to hospital if meningococcal disease (meningitis with non-blanching rash or meningococcal septicaemia) is suspected, once this does not delay transfer. Benzylpenicillin is no longer the drug of first choice for pneumococcal meningitis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 17
Correct
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A 30-year-old woman presents with a history of fever and sore throat. On examination, there is tonsillar exudate and cervical lymphadenopathy and a diagnosis of tonsillitis is made. A course of penicillin is prescribed.What is the mechanism of action of penicillin?
Your Answer: Inhibition of cell wall synthesis
Explanation:Penicillin is bactericidal and produces its antimicrobial action by preventing cross-linkage between the linear peptidoglycan polymer chains that make up the bacterial cell wall. This action inhibits cell wall synthesis.
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This question is part of the following fields:
- Infections
- Pharmacology
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Question 18
Incorrect
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A patient complains of stomach ache. You see a midline scar in the epigastric area when you examine the abdomen. Upon further interrogation, the patient reveals that she had a subtotal gastrectomy for recurring stomach ulcers several years ago. The stomach mucosa secretes a variety of vital compounds, and her ability to secrete some of these molecules has been harmed as a result of his surgery.The gastric ECL cells secrete which of the following substances?
Your Answer: Pepsinogen
Correct Answer: Histamine
Explanation:Enterochromaffin-like cells (ECL cells) are a type of neuroendocrine cell located beneath the epithelium in the stomach glands. They’re most typically located near the parietal cells of the stomach. The ECL cells’ primary role is to produce histamine, which stimulates the formation of stomach acid by the parietal cells.The table below summarizes the many cell types found in the stomach, as well as the substances secreted by each cell type and the function of the secretion:Cell type/ Substance secreted/ Function of secretionParietal cells/ Hydrochloric acid/ Kills microbes and activates pepsinogenParietal cells/ Intrinsic factor/Binds to vitamin B12 and facilitates its absorptionChief cells/ Pepsinogen/ Protein digestionChief cells/ Gastric lipase/ Fat digestionG-cells/ Gastrin/ Stimulates gastric acid secretionEnterochromaffin-like cells (ECL cells) /Histamine/ Stimulates gastric acid secretionMucous-neck cells/ Mucous and bicarbonate/ Protects stomach epithelium from acidD-cells/ Somatostatin/ Inhibits gastric acid secretion
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This question is part of the following fields:
- Gastrointestinal Physiology
- Physiology
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Question 19
Correct
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A 64-year-old lady attends the emergency department with a known brain tumour. Her left eye is directed outwards and downwards, she can't open it, and her pupil is fixed and dilated. The tumour is most likely compressing which of the following structures:
Your Answer: Oculomotor nerve
Explanation:The oculomotor nerve is the third cranial nerve. It is the main source of innervation to the extraocular muscles and also contains parasympathetic fibres which relay in the ciliary ganglion. Damage to the third cranial nerve may cause diplopia, pupil mydriasis, and/or upper eyelid ptosis. The clinical manifestations of third cranial nerve dysfunction reflect its constituent parts.
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This question is part of the following fields:
- Anatomy
- Cranial Nerve Lesions
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Question 20
Incorrect
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A newborn baby is referred by the community midwife who is concerned the baby is jaundiced because of the yellow appearance of his eyes and skin following a postnatal home visit. The jaundice is visible in the baby’s feet making her worried.Jaundice are visible in the extremities of neonates at what approximate threshold bilirubin level?
Your Answer: 100 μmol/L
Correct Answer: 255 μmol/L
Explanation:Newborn babies have a higher concentration of red blood cells with shorter lifespan leading to higher bilirubin levels than in adults. This condition is short-lived and harmless but with potential serious causes that need to be assessed for if present. The most obvious physical sign of jaundice is a yellow discolouration of the sclera, skin and mucous membranes. At a bilirubin level of 35 μmol/L or higher, the eye is affected. The bilirubin level will need to be higher than 255 μmol/L for the feet and extremities to be affected.
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This question is part of the following fields:
- General Pathology
- Pathology
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Question 21
Correct
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Which of the following medications can block the effect of adrenaline?
Your Answer: Beta-blockers
Explanation:Beta-blockers may reduce the response to adrenaline in the treatment of anaphylactic reactions. Noncardioselective beta-blockers in particular can antagonize the broncho dilating and cardio stimulatory effects of adrenaline by blocking beta-2 adrenergic receptors in the smooth muscles of the bronchial tree and in the heart muscles.
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This question is part of the following fields:
- Pharmacology
- Respiratory
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Question 22
Incorrect
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Which of the following is NOT a function of the commensal intestinal bacterial flora:
Your Answer: Convert primary bile acids to secondary bile acids
Correct Answer: Breakdown of haem into bilirubin
Explanation:Commensal intestinal bacterial flora have a role in:Keeping pathogenic bacteria at bay by competing for space and nutrientConverting conjugated bilirubin to urobilinogen (some of which is reabsorbed and excreted in urine) and stercobilinogen which is excreted in the faecesThe synthesis of vitamins K, B12, thiamine and riboflavinThe breakdown of primary bile acids to secondary bile acidsThe breakdown of cholesterol, some food additives and drugs
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This question is part of the following fields:
- Gastrointestinal
- Physiology
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Question 23
Correct
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If a lesion is observed in Broca's area, which function is expected to become affected?
Your Answer: Formation of words
Explanation:The primary functions of the Broca area are both language production and comprehension. While the exact role in the production is still unclear, many believe that it directly impacts the motor movements to allow for speech. Although originally thought to only aid in speech production, lesions in the area can rarely be related to impairments in the comprehension of language. Different regions of the Broca area specialize in various aspects of comprehension. The anterior portion helps with semantics, or word meaning, while the posterior is associated with phonology, or how words sound. The Broca area is also necessary for language repetition, gesture production, sentence grammar and fluidity, and the interpretation of others’ actions.Broca’s aphasia is a non-fluent aphasia in which the output of spontaneous speech is markedly diminished and there is a loss of normal grammatical structure. Specifically, small linking words, conjunctions, such as and, or, and but, and the use of prepositions are lost. Patients may exhibit interjectional speech where there is a long latency, and the words that are expressed are produced as if under pressure. The ability to repeat phrases is also impaired in patients with Broca’s aphasia. Despite these impairments, the words that are produced are often intelligible and contextually correct. In pure Broca’s aphasia, comprehension is intact.
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This question is part of the following fields:
- Anatomy
- Central Nervous System
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Question 24
Correct
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A 6-year-old child presents with profuse watery diarrhoea and dehydration. Which of the following statements is considered correct regarding infective diarrhoea?
Your Answer: E.Coli can cause diarrhoea and renal failure
Explanation:E. coli may cause several different gastrointestinal syndromes. Based on virulence factors, clinical manifestation, epidemiology, and different O and H serotypes, there are five major categories of diarrheagenic E. coli, enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterohemorrhagic E. coli (EHEC), and enteroadherent, which includes diffusely adherent E. coli (DAEC) and enteroaggregative E. coli (EAEC). These five categories are sometimescollectively referred to as enterovirulent E. coli or diarrheagenic E. coli.Norwalk virus is part of the Caliciviridae family of viruses which are single-stranded RNA viruses and are the most common cause of infectious gastroenteritis in the US.Rotaviruses are the most common cause of viral gastroenteritisin infants and children. With the introduction in 2006 of a human-bovine rotavirus vaccine (RV5; RotaTeq, Merck), a delay in the onset of rotavirusseason was seen. RotaTeq is a series of three oral vaccines beginning at 6 to 12 weeks of age. A second vaccine, Rotarix (RV1; GlaxoSmithKline, Middlesex, England), was approved in June 2008.Cryptosporidium causes an illness characterized by abdominal cramping, watery diarrhoea, vomiting, fever, and anorexia. This organism is resistant to chlorine, so public swimming pools can be the source of an outbreak.G. lamblia has a worldwide distribution and has frequently been identified as the causative agent of outbreaks of gastroenteritis and traveller’s diarrhoea.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 25
Correct
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Which of the following statements is false regarding the biceps brachii muscle?
Your Answer: It pronates the radioulnar joint in the forearm
Explanation:The biceps brachii muscle is one of the chief muscles of the arm. The origin at the scapula and the insertion into the radius of the biceps brachii means it can act on both the shoulder joint and the elbow joint, which is why this muscle participates in a few movements of the arm. It derives its name from its two heads which merge in one unique distal body, defining the unusual structure of the muscle.The biceps brachii muscle is supplied by the musculocutaneous nerve (C5-C6), a branch of the brachial plexus.Arterial supply to the biceps brachii muscle varies considerably, coming from up to eight vessels originating from the brachial artery in the middle third of the arm.In the shoulder joint both muscle heads partially enforce opposite movements. The long head pulls the arm away from the trunk (abduction) and turns it inwards (inward rotation) whereas the short head pulls the arm back towards the trunk (adduction). When both heads contract simultaneously it leads to an arm bend (flexion). In the elbow joint the muscle bends the forearm (flexion) and rotates it outwards (supination). The supination is most powerful in a flexed elbow. In addition to the movement functions, the biceps has the important task to support the humeral head within the shoulder joint. Its antagonist is the triceps brachii in the posterior compartment of the arm.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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Question 26
Incorrect
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A patient presents to ED with heartburn for which they already take regular antacids. Which of the following drugs can be affected if taken with antacids:
Your Answer: Bendroflumethiazine
Correct Answer: Digoxin
Explanation:Antacids should preferably not be taken at the same time as other drugs since they may affect absorption. When antacids are taken with acidic drugs (e.g. digoxin, phenytoin, chlorpromazine, isoniazid) they cause the absorption of the acidic drugs to be decreased, which causes low blood concentrations of the drugs, which ultimately results in reduced effects of the drugs. Antacids taken with drugs such as pseudoephedrine and levodopa increase absorption of the drugs and can cause toxicity/adverse events due to increased blood levels of the drugs. Antacids that contain magnesium trisilicate and magnesium hydroxide when taken with some other medications (such as tetracycline) will bind to the drugs, and reduce their absorption and effects.
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This question is part of the following fields:
- Gastrointestinal
- Pharmacology
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Question 27
Correct
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A 29-year-old man presents with painful red eye with copious discharge and you make a diagnosis of infective conjunctivitis following a history and an examination,.One of these is NOT an indication for an urgent ophthalmology referral in this patient.
Your Answer: Bilateral conjunctivitis
Explanation:Urgent referral to ophthalmology is indicated if the patient with conjunctivitis has any of the following:Suspected gonococcal or chlamydial conjunctivitisCorneal involvement associated with soft contact lens useSevere disease indicated by presence of a pseudomembraneConjunctivitis associated with rheumatoid arthritis or in immunocompromised patient. Ophthalmia neonatorum.Possible herpes infection.Had recent intraocular surgery. A red flag indicating a serious cause of red eye.Suspected periorbital or orbital cellulitis.Bilateral conjunctivitis is not an indication for urgent referral to ophthalmology.
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This question is part of the following fields:
- Microbiology
- Specific Pathogen Groups
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Question 28
Correct
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A 60 -year-old man is tested to have low calcium levels . After additional questioning, it becomes clear that he has a calcium-deficient diet.What is the daily calcium intake recommendation for a healthy adult?
Your Answer: 1300 mg
Explanation:A daily calcium intake of 1,000 to 1,300 mg is advised for adults. Women have a slightly higher calcium need than men and are at a higher risk of developing osteoporosis as they age.Calcium-rich foods include the following:Milk, cheese, and butter as dairy products.Broccoli, spinach, and green beans as green veggies.Bread, rice, and cereals as whole grain foods.Sardines, salmon, and other bony fishEggsNutsThe following foods have the least calcium:CarrotFruits such as kiwis, raspberries, oranges, and papayaChicken and pork in meats.
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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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A 36-year-old woman is 22-weeks pregnant and is investigated for a possible thyroid disorder. When her total thyroid hormone levels does not correlate with her thyrometabolic status, her thyroid-binding globulin levels are checked.What percentage of circulating thyroid hormones is bound to thyroid-binding globulin?
Your Answer: 70%
Explanation:Only a very small fraction of the thyroid hormones circulating in the blood are free. The majority is bound to transport proteins. Only the free thyroid hormones are biologically active, and measurement of total thyroid hormone levels can be misleading. The relative percentages of bound and unbound thyroid hormones are:Bound to thyroid-binding globulin -70%Bound to albumin -15-20%Bound to transthyretin -10-15%Free T3 -0.3%Free T4 -0.03%
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This question is part of the following fields:
- Endocrine Physiology
- Physiology
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Question 30
Correct
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A 44 year old woman is brought to ED having fallen down the stairs and injured her right arm. On examination she is unable to abduct her arm normally, and has weakness of lateral rotation. She has sensory loss over the lateral aspect of her upper arm. Which of the following injuries is most likely to produce this pattern of injury:
Your Answer: Surgical neck of humerus fracture
Explanation:Damage to the axillary nerve will result in loss of abduction past about 15 degrees and weakness of lateral rotation due to paralysis of the deltoid and teres minor and loss of sensation over the regimental badge area on the upper lateral arm. The axillary nerve is most likely injured in fracture of the surgical neck of the humerus due to its course where it winds around this region together with the posterior humeral circumflex vessels.
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This question is part of the following fields:
- Anatomy
- Upper Limb
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SESSION STATS - PERFORMANCE PER SPECIALTY
