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  • Question 1 - A 28-year-old male presents to his GP clinic with a history of unprotected...

    Incorrect

    • A 28-year-old male presents to his GP clinic with a history of unprotected sexual activity with a partner who has tested positive for Chlamydia trachomatis. Due to a penicillin allergy, what medical condition in his past would lead you to consider an alternative antibiotic for treatment, such as erythromycin?

      Your Answer: History of gastric ulcers

      Correct Answer: Prolonged QT interval

      Explanation:

      Macrolides are a class of antibiotics that include erythromycin, clarithromycin, and azithromycin. They work by blocking translocation during bacterial protein synthesis, ultimately inhibiting bacterial growth. While they are generally considered bacteriostatic, their effectiveness can vary depending on the dose and type of organism being treated. Resistance to macrolides can occur through post-transcriptional methylation of the 23S bacterial ribosomal RNA.

      However, macrolides can also have adverse effects. They may cause prolongation of the QT interval and gastrointestinal side-effects, such as nausea. Cholestatic jaundice is a potential risk, but using erythromycin stearate may reduce this risk. Additionally, macrolides are known to inhibit the cytochrome P450 isoenzyme CYP3A4, which metabolizes statins. Therefore, it is important to stop taking statins while on a course of macrolides to avoid the risk of myopathy and rhabdomyolysis. Azithromycin is also associated with hearing loss and tinnitus.

      Overall, while macrolides can be effective antibiotics, they do come with potential risks and side-effects. It is important to weigh the benefits and risks before starting a course of treatment with these antibiotics.

    • This question is part of the following fields:

      • General Principles
      33.3
      Seconds
  • Question 2 - A 22-year-old man is discovered unresponsive in his apartment after intentionally overdosing on...

    Incorrect

    • A 22-year-old man is discovered unresponsive in his apartment after intentionally overdosing on barbiturates. He is rushed to the hospital with sirens blaring.

      Upon being transported, he awakens and is evaluated with a Glasgow Coma Scale (GCS) score of 11 (E3V3M5).

      What is the primary type of ion channel that this medication targets to produce its sedative properties?

      Your Answer: Calcium

      Correct Answer: Chloride

      Explanation:

      Barbiturates prolong the opening of chloride channels

      Barbiturates are strong sedatives that have been used in the past as anesthetics and anti-epileptic drugs. They work in the central nervous system by binding to a subunit of the GABA receptor, which opens chloride channels. This results in an influx of chloride ions and hyperpolarization of the neuronal resting potential.

      The passage of calcium, magnesium, potassium, and sodium ions through channels, both actively and passively, is crucial for neuronal and peripheral function and is also targeted by other pharmacological agents.

      Barbiturates are commonly used in the treatment of anxiety and seizures, as well as for inducing anesthesia. They work by enhancing the action of GABAA, a neurotransmitter that helps to calm the brain. Specifically, barbiturates increase the duration of chloride channel opening, which allows more chloride ions to enter the neuron and further inhibit its activity. This is in contrast to benzodiazepines, which increase the frequency of chloride channel opening. A helpful mnemonic to remember this difference is Frequently Bend – During Barbeque or Barbiturates increase duration & Benzodiazepines increase frequency. Overall, barbiturates are an important class of drugs that can help to manage a variety of conditions by modulating the activity of GABAA in the brain.

    • This question is part of the following fields:

      • Neurological System
      30.7
      Seconds
  • Question 3 - Samantha is undergoing an evaluation with the psychologist. Her sister has joined the...

    Correct

    • Samantha is undergoing an evaluation with the psychologist. Her sister has joined the session to provide her with moral support. With Samantha's consent, the psychologist is inquiring her sister about her personality.
      Samantha's sister characterizes her to the psychologist as someone who appears to be lively, charming and sociable at first. However, as you spend more time with her, you come to realize that she is excessively theatrical, constantly seeking attention and admiration, and she can be quite manipulative.
      What kind of personality disorder does Samantha have?

      Your Answer: Histrionic personality disorder

      Explanation:

      Personality Disorders: General Criteria and Specific Types

      Personality disorders are a group of mental health conditions that are characterised by deviations from the cultural norm in cognition, affect, impulse control, or relating to others. According to ICD-10, individuals diagnosed with a personality disorder must meet certain general criteria, including long-term evidence of the deviation since childhood or adolescence, distress to the individual or negative impact on their social environment, and the absence of an alternative mental disorder or organic brain injury.

      There are several specific types of personality disorders, each with their own unique characteristics. Histrionic personality disorder is characterised by self-dramatisation, suggestibility, shallow affectivity, and a continual seeking for excitement and attention. Borderline personality disorder is associated with disturbances in self-image, intense relationships, emotional crises, and deliberate self-harm. Anankastic personality disorder is similar to obsessive-compulsive personality disorder, with individuals becoming preoccupied with detail, rules, and schedules to the point of hindering completion of tasks and relationships. Schizoid personality disorder is characterised by emotional detachment and solitary activities, while paranoid personality disorder involves high levels of suspicion and distrust towards others.

    • This question is part of the following fields:

      • Psychiatry
      43.4
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  • Question 4 - A pregnant woman arrives at the ER with a concern about her facial...

    Incorrect

    • A pregnant woman arrives at the ER with a concern about her facial appearance since waking up this morning. What signs would indicate a diagnosis of Bell's palsy, specifically a unilateral LMN lesion of the facial nerve?

      Your Answer: Bilateral facial weakness and loss of taste in the anterior 2/3 of the tongue

      Correct Answer: Unilateral facial weakness involving the forehead and unilateral failure of eye closure

      Explanation:

      When the facial nerve is unilaterally damaged, only the same side of the face is affected because this nerve does not cross over. Despite the fact that the facial nerve also transmits taste signals from the front two-thirds of the tongue, a lower motor neuron (LMN) injury only impacts the nerve’s motor function. This results in weakened facial expression muscles. The muscles in the forehead receive some innervation from the opposite side, so a LMN injury affects the forehead, while an upper motor neuron (UMN) injury does not affect the forehead.

      The facial nerve has a nucleus located in the ventrolateral pontine tegmentum, and its axons exit the ventral pons medial to the spinal trigeminal nucleus. Lesions affecting the corticobulbar tract are known as upper motor neuron lesions, while those affecting the individual branches of the facial nerve are lower motor neuron lesions. The lower motor neurons of the facial nerve can leave from either the left or right posterior or anterior facial motor nucleus, with the temporal branch receiving input from both hemispheres of the cerebral cortex, while the zygomatic, buccal, mandibular, and cervical branches receive input from only the contralateral hemisphere.

      In the case of an upper motor neuron lesion in the left hemisphere, the right mid- and lower-face would be paralyzed, while the forehead would remain unaffected. This is because the anterior facial motor nucleus receives only contralateral cortical input, while the posterior component receives input from both hemispheres. However, a lower motor neuron lesion affecting either the left or right side would paralyze the entire side of the face, as both the anterior and posterior routes on that side would be affected. This is because the nerves no longer have a means to receive compensatory contralateral input at a downstream decussation.

    • This question is part of the following fields:

      • Neurological System
      45.2
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  • Question 5 - A 89-year-old man presents to his GP with a recent change in his...

    Incorrect

    • A 89-year-old man presents to his GP with a recent change in his vision. He reports experiencing a gradual painless loss of vision in his left eye for about 5 minutes, described as a 'rising curtain', which has now resolved completely. The patient has a medical history of hypertension and dyslipidemia. Upon examination, both pupils are equal, round, and reactive to light, and fundoscopy shows no apparent pathology. What blood vessel is the most likely culprit for the patient's vision loss?

      Your Answer: Posterior inferior cerebellar artery

      Correct Answer: Central retinal artery

      Explanation:

      Amaurosis fugax is a type of transient ischaemic attack (TIA) that affects the central retinal artery, not stroke. The patient’s description of transient monocular vision loss that appears as a ‘rising curtain’ is characteristic of this condition. Urgent referral to a TIA clinic is necessary.

      Occlusion of the anterior spinal artery is not associated with vision loss, but may cause motor loss and loss of temperature and pain sensation below the level of the lesion.

      Occlusion of the central retinal vein may cause painless monocular vision loss, but not the characteristic ‘rising curtain’ distribution of vision loss seen in amaurosis fugax.

      Occlusion of the ophthalmic vein may cause a painful reduction in visual acuity, along with other symptoms such as ptosis, proptosis, and impaired visual acuity.

      Occlusion of the posterior inferior cerebellar artery is not associated with monocular vision loss, but is associated with lateral medullary syndrome.

      Stroke can affect different parts of the brain depending on which artery is affected. If the anterior cerebral artery is affected, the person may experience weakness and loss of sensation on the opposite side of the body, with the lower extremities being more affected than the upper. If the middle cerebral artery is affected, the person may experience weakness and loss of sensation on the opposite side of the body, with the upper extremities being more affected than the lower. They may also experience vision loss and difficulty with language. If the posterior cerebral artery is affected, the person may experience vision loss and difficulty recognizing objects.

      Lacunar strokes are a type of stroke that are strongly associated with hypertension. They typically present with isolated weakness or loss of sensation on one side of the body, or weakness with difficulty coordinating movements. They often occur in the basal ganglia, thalamus, or internal capsule.

    • This question is part of the following fields:

      • Neurological System
      59.6
      Seconds
  • Question 6 - At 28 years old, Gwen seeks pre-conception advice from her haematologist regarding her...

    Incorrect

    • At 28 years old, Gwen seeks pre-conception advice from her haematologist regarding her Von Willebrand Disease (VWD). She is concerned about the potential risks of bleeding during pregnancy and childbirth, as well as the likelihood of passing on her condition to her child. Gwen is a carrier of VWD, while her partner Dylan does not have the condition. What is the probability of their child inheriting VWD?

      Your Answer: 25%

      Correct Answer: 50%

      Explanation:

      The offspring of Gwen and Dylan will have the Vv allele combination, resulting in inheriting VWD with a probability of 50%.

      Autosomal Dominant Inheritance: Characteristics and Complicating Factors

      Autosomal dominant diseases are genetic disorders that are inherited in an autosomal dominant pattern. This means that both homozygotes and heterozygotes manifest the disease, and there is no carrier state. Both males and females can be affected, and only affected individuals can pass on the disease. The disease is passed on to 50% of children, and it normally appears in every generation. The risk remains the same for each successive pregnancy.

      However, there are complicating factors that can affect the inheritance of autosomal dominant diseases. One of these factors is non-penetrance, which refers to the lack of clinical signs and symptoms despite having an abnormal gene. For example, 40% of individuals with otosclerosis may not show any symptoms. Another complicating factor is spontaneous mutation, which occurs when there is a new mutation in one of the gametes. This means that 80% of individuals with achondroplasia have unaffected parents.

      In summary, autosomal dominant inheritance is characterized by certain patterns of inheritance, but there are also complicating factors that can affect the expression of the disease. Understanding these factors is important for genetic counseling and for predicting the risk of passing on the disease to future generations.

    • This question is part of the following fields:

      • General Principles
      23.4
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  • Question 7 - A 25-year-old G1P0 woman, who missed all previous antenatal appointments, presents to the...

    Correct

    • A 25-year-old G1P0 woman, who missed all previous antenatal appointments, presents to the obstetrics clinic at 34 weeks' gestation for her first antenatal visit. The mother has no significant medical history and is in good health. She is up to date with all her immunisations.

      During the examination, the symphyseal-fundal height measures 30cm. An ultrasound scan is conducted, which reveals that the fetus has an abdominal circumference below the 3rd percentile for age, femur length below the 3rd percentile, and head circumference along the 90th percentile. The estimated weight of the baby is below the 10th percentile.

      What is the most probable cause of the abnormality observed in this fetus?

      Your Answer: Maternal smoking

      Explanation:

      Smoking while pregnant has been linked to the birth of a Small for Gestational Age baby. This is indicated by the baby’s birth weight being below the 10th percentile and fetal measurements suggesting asymmetrical intrauterine growth restriction (IUGR), with the head circumference being significantly higher than the abdominal circumference and femur length. Maternal smoking is a possible cause of the baby’s small size, as it has been associated with reduced birth weight and asymmetrical IUGR. Multiple gestation is a known risk factor for fetal growth restriction, but singleton gestation is not. Maternal rubella infection and advanced maternal age may also cause small for gestational age babies, but these are less likely causes in this case as the mother’s immunisations are up to date and she is only 23 years old.

      Small for Gestational Age (SGA) is a statistical definition used to describe babies who are smaller than expected for their gestational age. Although there is no universally agreed percentile, the 10th percentile is often used, meaning that 10% of normal babies will be below this threshold. SGA can be determined either antenatally or postnatally. There are two types of SGA: symmetrical and asymmetrical. Symmetrical SGA occurs when the fetal head circumference and abdominal circumference are equally small, while asymmetrical SGA occurs when the abdominal circumference slows relative to the increase in head circumference.

      There are various causes of SGA, including incorrect dating, constitutionally small (normal) babies, and abnormal fetuses. Symmetrical SGA is more common and can be caused by idiopathic factors, race, sex, placental insufficiency, pre-eclampsia, chromosomal and congenital abnormalities, toxins such as smoking and heroin, and infections such as CMV, parvovirus, rubella, syphilis, and toxoplasmosis. Asymmetrical SGA is less common and can be caused by toxins such as alcohol, cigarettes, and heroin, chromosomal and congenital abnormalities, and infections.

      The management of SGA depends on the type and cause. For symmetrical SGA, most cases represent the lower limits of the normal range and require fortnightly ultrasound growth assessments to demonstrate normal growth rates. Pathological causes should be ruled out by checking maternal blood for infections and searching the fetus carefully with ultrasound for markers of chromosomal abnormality. Asymmetrical SGA also requires fortnightly ultrasound growth assessments, as well as biophysical profiles and Doppler waveforms from umbilical circulation to look for absent end-diastolic flow. If results are sub-optimal, delivery may be considered.

    • This question is part of the following fields:

      • Reproductive System
      97.7
      Seconds
  • Question 8 - A 79-year-old male arrives at the emergency department with sudden onset right sided...

    Incorrect

    • A 79-year-old male arrives at the emergency department with sudden onset right sided hemiparesis. He has a medical history of hypertension and reports no changes to his vision, speech or hearing.

      What is the probable diagnosis?

      Your Answer: Lateral pontine syndrome

      Correct Answer: Lacunar infarct

      Explanation:

      A lacunar stroke can lead to isolated hemiparesis, hemisensory loss, or hemiparesis with limb ataxia. In this case, the patient is experiencing isolated hemiparesis, which is likely caused by a lacunar infarct. Hypertension is strongly linked to this type of stroke.

      Weber’s syndrome results in CN III palsy on the same side as the stroke and weakness in the opposite limb.

      Nystagmus is a common symptom of Wallenberg syndrome.

      Ipsilateral deafness is a common symptom of lateral pontine syndrome.

      Stroke can affect different parts of the brain depending on which artery is affected. If the anterior cerebral artery is affected, the person may experience weakness and loss of sensation on the opposite side of the body, with the lower extremities being more affected than the upper. If the middle cerebral artery is affected, the person may experience weakness and loss of sensation on the opposite side of the body, with the upper extremities being more affected than the lower. They may also experience vision loss and difficulty with language. If the posterior cerebral artery is affected, the person may experience vision loss and difficulty recognizing objects.

      Lacunar strokes are a type of stroke that are strongly associated with hypertension. They typically present with isolated weakness or loss of sensation on one side of the body, or weakness with difficulty coordinating movements. They often occur in the basal ganglia, thalamus, or internal capsule.

    • This question is part of the following fields:

      • Neurological System
      65.1
      Seconds
  • Question 9 - A 55-year-old man comes to the clinic complaining of black tarry stools. Upon...

    Incorrect

    • A 55-year-old man comes to the clinic complaining of black tarry stools. Upon endoscopy, he is found to have a peptic ulcer. What is the primary risk factor for developing peptic ulcers?

      Your Answer: Non-steroidal anti-inflammatory drugs (NSAIDs)

      Correct Answer: Helicobacter pylori colonisation of the stomach

      Explanation:

      Causes of Peptic Ulcers

      Peptic ulcers are a common condition that can cause discomfort and pain in the stomach. The most common cause of peptic ulcers is the presence of Helicobacter pylori bacteria in the stomach. This bacteria can cause inflammation and damage to the lining of the stomach, leading to the formation of ulcers. Another common cause of peptic ulcers is the use of nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs can suppress the production of prostaglandins in the stomach, which can lead to inflammation and damage to the stomach lining.

      In addition to these causes, smoking can also increase the risk of developing peptic ulcers. Smoking can suppress the production of prostaglandins in the stomach, impair mucosal blood flow, and increase gastric acid secretion. However, it is important to note that being female is not a risk factor for peptic ulcers. In fact, men are more likely to be affected by this condition. Overall, the causes of peptic ulcers can help individuals take steps to prevent and manage this condition.

    • This question is part of the following fields:

      • Clinical Sciences
      18.4
      Seconds
  • Question 10 - A 33-year-old man arrives at the emergency department with complaints of decreased mobility....

    Incorrect

    • A 33-year-old man arrives at the emergency department with complaints of decreased mobility. He reports experiencing difficulty walking due to weakness in his left foot. The patient has no significant medical history and is typically healthy, regularly participating in sports.

      Upon examination, there is a decrease in sensation in the lateral aspect of the left foot and the posterior aspect of the left leg. The patient exhibits normal power on dorsiflexion but reduced power on plantarflexion of the left foot. Additionally, ankle reflexes are absent.

      Which anatomical structure is likely to be damaged and causing the patient's symptoms?

      Your Answer: Common fibular nerve

      Correct Answer: S1 nerve root

      Explanation:

      The patient’s symptoms suggest a lesion in the S1 nerve root, which supplies sensation to the posterolateral aspect of the leg and lateral aspect of the foot. This is supported by the presence of sensory loss, weakness in plantarflexion of the foot, reduced ankle reflex, and a positive sciatic nerve stretch test. The other options, such as Achilles tendon rupture, injury to the common fibular nerve, or L4-L5 nerve root compression, do not fully explain the patient’s symptoms.

      Understanding Prolapsed Disc and its Features

      A prolapsed disc in the lumbar region can cause leg pain and neurological deficits. The pain is usually more severe in the leg than in the back and worsens when sitting. The features of the prolapsed disc depend on the site of compression. For instance, compression of the L3 nerve root can cause sensory loss over the anterior thigh, weak quadriceps, reduced knee reflex, and a positive femoral stretch test. On the other hand, compression of the L4 nerve root can cause sensory loss in the anterior aspect of the knee, weak quadriceps, reduced knee reflex, and a positive femoral stretch test.

      Similarly, compression of the L5 nerve root can cause sensory loss in the dorsum of the foot, weakness in foot and big toe dorsiflexion, intact reflexes, and a positive sciatic nerve stretch test. Lastly, compression of the S1 nerve root can cause sensory loss in the posterolateral aspect of the leg and lateral aspect of the foot, weakness in plantar flexion of the foot, reduced ankle reflex, and a positive sciatic nerve stretch test.

      The management of prolapsed disc is similar to that of other musculoskeletal lower back pain, which includes analgesia, physiotherapy, and exercises. However, if the symptoms persist even after 4-6 weeks, referral for an MRI is appropriate. Understanding the features of prolapsed disc can help in early diagnosis and prompt management.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      181.3
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  • Question 11 - Ehlers Danlos syndrome is typically a result of collagen type V defects. Which...

    Incorrect

    • Ehlers Danlos syndrome is typically a result of collagen type V defects. Which type of collagen is the most prevalent?

      Your Answer: Collagen Type II

      Correct Answer: Collagen Type I

      Explanation:

      The most prevalent type of collagen is Type I, which can be found in bones, skin, and tendons. Type II collagen is present in hyaline cartilage and vitreous humor, while Type III collagen is found in reticular fibers and granulation tissue. Type IV collagen is located in the basal lamina, lens, and basement membrane, and Type V collagen is present in most interstitial tissue and placental tissue.

      Understanding Collagen and its Associated Disorders

      Collagen is a vital protein found in connective tissue and is the most abundant protein in the human body. Although there are over 20 types of collagen, the most important ones are types I, II, III, IV, and V. Collagen is composed of three polypeptide strands that are woven into a helix, with numerous hydrogen bonds providing additional strength. Vitamin C plays a crucial role in establishing cross-links, and fibroblasts synthesize collagen.

      Disorders of collagen can range from acquired defects due to aging to rare congenital disorders. Osteogenesis imperfecta is a congenital disorder that has eight subtypes and is caused by a defect in type I collagen. Patients with this disorder have bones that fracture easily, loose joints, and other defects depending on the subtype. Ehlers Danlos syndrome is another congenital disorder that has multiple subtypes and is caused by an abnormality in types 1 and 3 collagen. Patients with this disorder have features of hypermobility and are prone to joint dislocations and pelvic organ prolapse, among other connective tissue defects.

    • This question is part of the following fields:

      • General Principles
      11.8
      Seconds
  • Question 12 - A 15-year-old girl presents with a painful swelling in her distal femur. After...

    Incorrect

    • A 15-year-old girl presents with a painful swelling in her distal femur. After diagnosis, it is revealed that she has osteoblastic sarcoma. What is the most probable site for metastasis of this lesion?

      Your Answer: Common iliac lymph nodes

      Correct Answer: Lung

      Explanation:

      Sarcomas that exhibit lymphatic metastasis can be remembered using the acronym ‘RACE For MS’, which stands for Rhabdomyosarcoma, Angiosarcoma, Clear cell sarcoma, Epithelial cell sarcoma, Fibrosarcoma, Malignant fibrous histiocytoma, and Synovial cell sarcoma. Alternatively, the acronym ‘SCARE’ can be used to remember Synovial sarcoma, Clear cell sarcoma, Angiosarcoma, Rhabdomyosarcoma, and Epithelioid sarcoma. While sarcomas typically metastasize through the bloodstream and commonly spread to the lungs, lymphatic metastasis is less common but may occur in some cases. The liver and brain are typically spared from initial metastasis.

      Sarcomas: Types, Features, and Assessment

      Sarcomas are malignant tumors that originate from mesenchymal cells. They can either be bone or soft tissue in origin. Bone sarcomas include osteosarcoma, Ewing’s sarcoma, and chondrosarcoma, while soft tissue sarcomas are a more diverse group that includes liposarcoma, rhabdomyosarcoma, leiomyosarcoma, and synovial sarcomas. Malignant fibrous histiocytoma is a sarcoma that can arise in both soft tissue and bone.

      Certain features of a mass or swelling should raise suspicion for a sarcoma, such as a large (>5cm) soft tissue mass, deep tissue or intra-muscular location, rapid growth, and a painful lump. Imaging of suspicious masses should utilize a combination of MRI, CT, and USS. Blind biopsy should not be performed prior to imaging, and where required, should be done in such a way that the biopsy tract can be subsequently included in any resection.

      Ewing’s sarcoma is more common in males, with an incidence of 0.3/1,000,000 and onset typically between 10 and 20 years of age. Osteosarcoma is more common in males, with an incidence of 5/1,000,000 and peak age 15-30. Liposarcoma is rare, with an incidence of approximately 2.5/1,000,000, and typically affects an older age group (>40 years of age). Malignant fibrous histiocytoma is the most common sarcoma in adults and is usually treated with surgical resection and adjuvant radiotherapy.

      In summary, sarcomas are a diverse group of malignant tumors that can arise from bone or soft tissue. Certain features of a mass or swelling should raise suspicion for a sarcoma, and imaging should utilize a combination of MRI, CT, and USS. Treatment options vary depending on the type and location of the sarcoma.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      46.4
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  • Question 13 - A 63-year-old man is being evaluated on the medical ward after undergoing surgery...

    Correct

    • A 63-year-old man is being evaluated on the medical ward after undergoing surgery to remove a suspicious thyroid nodule. His vital signs are stable, his pain is adequately managed, and he is able to consume soft foods and drink oral fluids. He reports feeling generally fine, but has observed a hoarseness in his voice.

      What is the probable reason for his hoarseness?

      Your Answer: Damage to recurrent laryngeal nerve

      Explanation:

      Hoarseness is often linked to recurrent laryngeal nerve injury, which can affect the opening of the vocal cords by innervating the posterior arytenoid muscles. This type of damage can result from surgery, such as thyroidectomy, or compression from tumors. On the other hand, glossopharyngeal nerve damage is more commonly associated with swallowing difficulties. Since the patient is able to consume food orally, a dry throat is unlikely to be the cause of her hoarseness. While intubation trauma could cause vocal changes, the absence of pain complaints makes it less likely. Additionally, the lack of other symptoms suggests that an upper respiratory tract infection is not the cause.

      The Recurrent Laryngeal Nerve: Anatomy and Function

      The recurrent laryngeal nerve is a branch of the vagus nerve that plays a crucial role in the innervation of the larynx. It has a complex path that differs slightly between the left and right sides of the body. On the right side, it arises anterior to the subclavian artery and ascends obliquely next to the trachea, behind the common carotid artery. It may be located either anterior or posterior to the inferior thyroid artery. On the left side, it arises left to the arch of the aorta, winds below the aorta, and ascends along the side of the trachea.

      Both branches pass in a groove between the trachea and oesophagus before entering the larynx behind the articulation between the thyroid cartilage and cricoid. Once inside the larynx, the recurrent laryngeal nerve is distributed to the intrinsic larynx muscles (excluding cricothyroid). It also branches to the cardiac plexus and the mucous membrane and muscular coat of the oesophagus and trachea.

      Damage to the recurrent laryngeal nerve, such as during thyroid surgery, can result in hoarseness. Therefore, understanding the anatomy and function of this nerve is crucial for medical professionals who perform procedures in the neck and throat area.

    • This question is part of the following fields:

      • Neurological System
      37.8
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  • Question 14 - A 48-year-old male visits his GP with blister-like skin alterations that have been...

    Incorrect

    • A 48-year-old male visits his GP with blister-like skin alterations that have been bothering him for a few months on his body and inside his mouth. Upon biopsy, it is revealed that there are intra-epithelial blisters containing acantholytic keratinocytes.

      What skin condition is known to present with these features?

      Your Answer: Actinic keratosis

      Correct Answer: Pemphigus vulgaris

      Explanation:

      Pemphigus vulgaris is likely the condition that a middle-aged man with acantholytic keratinocytes and involvement of the mouth (mucous membranes) would present with. This is because this condition is characterised by intra-epithelial blisters containing acantholytic keratinocytes.

      Bullous pemphigoid, on the other hand, is characterised by damage to the hemidesmosomes and infiltration of white blood cells such as lymphocytes into the affected area. It does not demonstrate acantholytic keratinocytes and does not affect mucous membranes like the mouth.

      Actinic keratosis does not cause blistering, and bullous impetigo typically affects babies.

      Pemphigus vulgaris is an autoimmune condition that occurs when the body’s immune system attacks desmoglein 3, a type of cell adhesion molecule found in epithelial cells. This disease is more prevalent in the Ashkenazi Jewish population. The most common symptom is mucosal ulceration, which can be the first sign of the disease. Oral involvement is seen in 50-70% of patients. Skin blistering is also a common symptom, with easily ruptured vesicles and bullae. These lesions are typically painful but not itchy and may appear months after the initial mucosal symptoms. Nikolsky’s sign is a characteristic feature of pemphigus vulgaris, where bullae spread following the application of horizontal, tangential pressure to the skin. Biopsy results often show acantholysis.

      The first-line treatment for pemphigus vulgaris is steroids, which help to reduce inflammation and suppress the immune system. Immunosuppressants may also be used to manage the disease.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      28.8
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  • Question 15 - A 33-year-old woman with a history of coeliac disease presents to the emergency...

    Incorrect

    • A 33-year-old woman with a history of coeliac disease presents to the emergency department with palpitations, diaphoresis, and tremors. Upon examination, her vital signs reveal a heart rate of 110 bpm and respiratory rate of 24 per min. She displays hand tremors, bulging eyeballs, and diffuse swelling in her neck. Her blood tests show:

      TSH 0.1 mU/l
      Free T4 32.5 pmol/l
      Free T3 12.5 pmol/l

      What is the most probable underlying pathophysiology in this patient?

      Your Answer: Excessive iodine consumption

      Correct Answer: Antibodies to TSH receptors

      Explanation:

      Graves’ disease is the most probable cause of thyrotoxicosis in a middle-aged woman, particularly if she exhibits exophthalmos. This autoimmune disorder is characterised by the presence of antibodies to the thyroid stimulating hormone (TSH) receptors.

      Graves’ Disease: Common Features and Unique Signs

      Graves’ disease is the most frequent cause of thyrotoxicosis, which is commonly observed in women aged 30-50 years. The condition presents typical features of thyrotoxicosis, such as weight loss, palpitations, and heat intolerance. However, Graves’ disease also displays specific signs that are not present in other causes of thyrotoxicosis. These include eye signs, such as exophthalmos and ophthalmoplegia, as well as pretibial myxoedema and thyroid acropachy. The latter is a triad of digital clubbing, soft tissue swelling of the hands and feet, and periosteal new bone formation.

      Graves’ disease is characterized by the presence of autoantibodies, including TSH receptor stimulating antibodies in 90% of patients and anti-thyroid peroxidase antibodies in 75% of patients. Thyroid scintigraphy reveals a diffuse, homogenous, and increased uptake of radioactive iodine. These features help distinguish Graves’ disease from other causes of thyrotoxicosis and aid in its diagnosis.

    • This question is part of the following fields:

      • Endocrine System
      38.3
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  • Question 16 - A midwife contacts the Obstetric Foundation Year 2 doctor to assess a 32-year-old...

    Incorrect

    • A midwife contacts the Obstetric Foundation Year 2 doctor to assess a 32-year-old patient who delivered vaginally an hour ago. The patient is experiencing continuous vaginal bleeding, and the midwife approximates a total blood loss of 600 millilitres. What is the leading cause of primary postpartum haemorrhage?

      Your Answer: Perineal trauma

      Correct Answer: Uterine atony

      Explanation:

      PPH, which is the loss of 500 millilitres or more of blood within 24 hours of delivery, is primarily caused by uterine atony. This occurs when the uterus fails to contract after the placenta is delivered. However, other potential causes must be ruled out through thorough clinical examination. To remember the causes of PPH, the acronym ‘the 4 Ts’ can be used: Tone (uterine atony), Tissue (retained products of conception), Trauma (to the genital tract or perineum), and Thrombin (coagulation abnormalities). This information is based on RCOG Green-top Guideline No. 52.

      Postpartum Haemorrhage: Causes, Risk Factors, and Management

      Postpartum haemorrhage (PPH) is a condition characterized by excessive blood loss of more than 500 ml after a vaginal delivery. It can be primary or secondary. Primary PPH occurs within 24 hours after delivery and is caused by the 4 Ts: tone, trauma, tissue, and thrombin. The most common cause is uterine atony. Risk factors for primary PPH include previous PPH, prolonged labour, pre-eclampsia, increased maternal age, emergency Caesarean section, and placenta praevia. Management of PPH is a life-threatening emergency that requires immediate involvement of senior staff. The ABC approach is used, and bloods are taken, including group and save. Medical management includes IV oxytocin, ergometrine, carboprost, and misoprostol. Surgical options are considered if medical management fails to control the bleeding. Secondary PPH occurs between 24 hours to 6 weeks after delivery and is typically due to retained placental tissue or endometritis.

      Understanding Postpartum Haemorrhage

      Postpartum haemorrhage is a serious condition that can occur after vaginal delivery. It is important to understand the causes, risk factors, and management of this condition to ensure prompt and effective treatment. Primary PPH is caused by the 4 Ts, with uterine atony being the most common cause. Risk factors for primary PPH include previous PPH, prolonged labour, and emergency Caesarean section. Management of PPH is a life-threatening emergency that requires immediate involvement of senior staff. Medical management includes IV oxytocin, ergometrine, carboprost, and misoprostol. Surgical options are considered if medical management fails to control the bleeding. Secondary PPH occurs between 24 hours to 6 weeks after delivery and is typically due to retained placental tissue or endometritis. It is important to be aware of the signs and symptoms of PPH and seek medical attention immediately if they occur.

    • This question is part of the following fields:

      • Reproductive System
      34.9
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  • Question 17 - A 41-year-old male presents to the general practitioner with a 4-month history of...

    Incorrect

    • A 41-year-old male presents to the general practitioner with a 4-month history of a lump in his right testicle. On examination, there is a discrete nodule located near the superior pole of the right testicle and the left testicle is unremarkable. The patient is referred for further investigations and is ultimately diagnosed with a testicular seminoma.

      In this patient, what is the most likely lymph node region for initial metastatic spread?

      Your Answer: Internal iliac nodes

      Correct Answer: Para-aortic nodes

      Explanation:

      The para-aortic nodes are responsible for receiving lymph drainage from the testes. This is because the testes develop in the abdomen and move down the posterior abdominal wall during fetal development, leading to their lymphatic drainage coming from the para-aortic lymph nodes. Therefore, the para-aortic nodes are the most likely location for lymphatic spread from the testes.

      The inferior mesenteric nodes are not responsible for lymph drainage from the testes as they primarily drain hindgut structures such as the transverse colon down to the rectum. Similarly, the internal iliac nodes drain the inferior portion of the rectum, the anal canal superior to the pectinate line, and the pelvic viscera, but not the testes. The posterior mediastinal chain is also not responsible for lymph drainage from the testes as it drains the oesophagus, mediastinum, and posterior surface of the diaphragm.

      Lymphatic drainage is the process by which lymphatic vessels carry lymph, a clear fluid containing white blood cells, away from tissues and organs and towards lymph nodes. The lymphatic vessels that drain the skin and follow venous drainage are called superficial lymphatic vessels, while those that drain internal organs and structures follow the arteries and are called deep lymphatic vessels. These vessels eventually lead to lymph nodes, which filter and remove harmful substances from the lymph before it is returned to the bloodstream.

      The lymphatic system is divided into two main ducts: the right lymphatic duct and the thoracic duct. The right lymphatic duct drains the right side of the head and right arm, while the thoracic duct drains everything else. Both ducts eventually drain into the venous system.

      Different areas of the body have specific primary lymph node drainage sites. For example, the superficial inguinal lymph nodes drain the anal canal below the pectinate line, perineum, skin of the thigh, penis, scrotum, and vagina. The deep inguinal lymph nodes drain the glans penis, while the para-aortic lymph nodes drain the testes, ovaries, kidney, and adrenal gland. The axillary lymph nodes drain the lateral breast and upper limb, while the internal iliac lymph nodes drain the anal canal above the pectinate line, lower part of the rectum, and pelvic structures including the cervix and inferior part of the uterus. The superior mesenteric lymph nodes drain the duodenum and jejunum, while the inferior mesenteric lymph nodes drain the descending colon, sigmoid colon, and upper part of the rectum. Finally, the coeliac lymph nodes drain the stomach.

    • This question is part of the following fields:

      • Haematology And Oncology
      31.6
      Seconds
  • Question 18 - A 9-year-old girl is taken to her doctor by her father with intense...

    Incorrect

    • A 9-year-old girl is taken to her doctor by her father with intense throat discomfort and is diagnosed with a probable bacterial throat infection. The doctor prescribes an antibiotic that specifically targets bacterial protein synthesis.

      What is the name of the prescribed antibiotic?

      Your Answer: Ciprofloxacin

      Correct Answer: Erythromycin

      Explanation:

      Bacterial protein synthesis is the target of erythromycin.

      Bacterial division is inhibited by ciprofloxacin through targeting DNA gyrase.

      The production of bacterial cell wall is inhibited by penicillin through targeting the beta-lactam ring.

      The activation of folic acid in susceptible organisms is inhibited by trimethoprim.

      The mechanism of action of antibiotics can be categorized into inhibiting cell wall formation, protein synthesis, DNA synthesis, and RNA synthesis. Beta-lactams such as penicillins and cephalosporins inhibit cell wall formation by blocking cross-linking of peptidoglycan cell walls. Antibiotics that inhibit protein synthesis include aminoglycosides, chloramphenicol, macrolides, tetracyclines, and fusidic acid. Quinolones, metronidazole, sulphonamides, and trimethoprim inhibit DNA synthesis, while rifampicin inhibits RNA synthesis.

    • This question is part of the following fields:

      • General Principles
      11.9
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  • Question 19 - A fifteen-year-old comes in with a swollen, red, and tender first metatarsophalangeal joint....

    Incorrect

    • A fifteen-year-old comes in with a swollen, red, and tender first metatarsophalangeal joint. After diagnosis and treatment for gout, he confesses to having experienced three previous episodes. What medical condition is linked to gout?

      Your Answer: Edwards syndrome

      Correct Answer: Lesch-Nyhan syndrome

      Explanation:

      Gout is commonly associated with Lesch-Nyhan syndrome, an inherited enzyme deficiency also known as ‘juvenile gout’. This condition is also characterized by self-injuring behavior, cognitive impairment, and nervous system impairment. However, juvenile idiopathic arthritis and osteoarthritis, which also cause joint pain and swelling, are not strongly linked to gout. On the other hand, pseudogout is associated with hyperparathyroidism.

      Predisposing Factors for Gout

      Gout is a type of synovitis caused by the accumulation of monosodium urate monohydrate in the synovium. This condition is triggered by chronic hyperuricaemia, which is characterized by uric acid levels exceeding 0.45 mmol/l. There are two main factors that contribute to the development of hyperuricaemia: decreased excretion of uric acid and increased production of uric acid.

      Decreased excretion of uric acid can be caused by various factors, including the use of diuretics, chronic kidney disease, and lead toxicity. On the other hand, increased production of uric acid can be triggered by myeloproliferative/lymphoproliferative disorders, cytotoxic drugs, and severe psoriasis.

      In rare cases, gout can also be caused by genetic disorders such as Lesch-Nyhan syndrome, which is characterized by hypoxanthine-guanine phosphoribosyl transferase (HGPRTase) deficiency. This condition is x-linked recessive, which means it is only seen in boys. Lesch-Nyhan syndrome is associated with gout, renal failure, neurological deficits, learning difficulties, and self-mutilation.

      It is worth noting that aspirin in low doses (75-150mg) is not believed to have a significant impact on plasma urate levels. Therefore, the British Society for Rheumatology recommends that it should be continued if necessary for cardiovascular prophylaxis.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      24.6
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  • Question 20 - A 7-year-old female comes to the doctor's office with her father. They have...

    Correct

    • A 7-year-old female comes to the doctor's office with her father. They have recently moved from South America to the US. She has been complaining of pain and tenderness in both legs, which has been getting worse over the past few months. Her father is worried because she has been avoiding walking and putting weight on her legs. During the examination, there is noticeable bowing and tenderness in both tibias. What vitamin deficiency is she likely experiencing?

      Your Answer: Vitamin D

      Explanation:

      Rickets is caused by insufficient vitamin D, which can result from inadequate exposure to sunlight and poor dietary habits. Although any child can develop this condition, those with darker skin, particularly those of Asian and Afro-Caribbean descent, are at a greater risk due to their reduced ability to absorb sunlight and cultural practices that involve wearing clothing that covers most of their body.

      Understanding Vitamin D

      Vitamin D is a type of vitamin that is soluble in fat and is essential for the metabolism of calcium and phosphate in the body. It is converted into calcifediol in the liver and then into calcitriol, which is the active form of vitamin D, in the kidneys. Vitamin D can be obtained from two sources: vitamin D2, which is found in plants, and vitamin D3, which is present in dairy products and can also be synthesized by the skin when exposed to sunlight.

      The primary function of vitamin D is to increase the levels of calcium and phosphate in the blood. It achieves this by increasing the absorption of calcium in the gut and the reabsorption of calcium in the kidneys. Vitamin D also stimulates osteoclastic activity, which is essential for bone growth and remodeling. Additionally, it increases the reabsorption of phosphate in the kidneys.

      A deficiency in vitamin D can lead to two conditions: rickets in children and osteomalacia in adults. Rickets is characterized by soft and weak bones, while osteomalacia is a condition where the bones become weak and brittle. Therefore, it is crucial to ensure that the body receives an adequate amount of vitamin D to maintain healthy bones and overall health.

    • This question is part of the following fields:

      • General Principles
      27.8
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  • Question 21 - A 12-year-old girl is admitted with arthralgia. On examination she has purpura of...

    Incorrect

    • A 12-year-old girl is admitted with arthralgia. On examination she has purpura of her lower limbs. Urinalysis reveals haematuria.

      Blood results are as follows:

      Na+ 133 mmol/l
      K+ 3.8 mmol/l
      Urea 10.2 mmol/l
      Creatinine 114 µmol/l

      What is the underlying mechanism causing the renal dysfunction in this case?

      Your Answer: Macrophages

      Correct Answer: Classical complement pathway

      Explanation:

      The activation of the classical complement pathway is triggered by the presence of antigen-antibody complexes, specifically IgM/IgG. However, in cases of systemic diseases like systemic lupus erythematosus, anti-GBM disease, and ANCA-associated glomerulonephritis, the involvement of autoantibodies in the classical pathway can lead to glomerulonephritis.

      The cell-mediated response involves Th1 lymphocytes, while the humoral (antibody) response involves Th2 lymphocytes. Antigen presenting cells, such as macrophages and dendritic cells, play a crucial role in processing antigenic material and presenting it to lymphocytes.

      Overview of Complement Pathways

      Complement pathways are a group of proteins that play a crucial role in the body’s immune and inflammatory response. These proteins are involved in various processes such as chemotaxis, cell lysis, and opsonisation. There are two main complement pathways: classical and alternative.

      The classical pathway is initiated by antigen-antibody complexes, specifically IgM and IgG. The proteins involved in this pathway include C1qrs, C2, and C4. On the other hand, the alternative pathway is initiated by polysaccharides found in Gram-negative bacteria and IgA. The proteins involved in this pathway are C3, factor B, and properdin.

      Understanding the complement pathways is important in the diagnosis and treatment of various diseases. Dysregulation of these pathways can lead to autoimmune disorders, infections, and other inflammatory conditions. By identifying the specific complement pathway involved in a disease, targeted therapies can be developed to effectively treat the condition.

    • This question is part of the following fields:

      • General Principles
      29
      Seconds
  • Question 22 - A 75-year-old man presents to the ophthalmology clinic with complaints of gradually worsening...

    Incorrect

    • A 75-year-old man presents to the ophthalmology clinic with complaints of gradually worsening peripheral vision and a progressive headache that is worse at night. During the cranial nerve exam, a superior homonymous quadrantanopia is observed, but eye movements are intact. The rest of the cranial nerve and neurological examinations are unremarkable.

      Which region of the brain is likely affected by the lesion causing these symptoms?

      Your Answer: Optic nerve

      Correct Answer: Temporal lobe

      Explanation:

      Superior homonymous quadrantanopias occur when there are lesions in the inferior optic radiations located in the temporal lobe. The location of the lesion can be determined by analyzing the pattern of the visual field defect. Lesions in front of the optic chiasm cause incongruous defects, while lesions at the optic chiasm cause bitemporal/binasal hemianopias. Lesions behind the optic chiasm result in homonymous hemianopias, such as the superior homonymous quadrantanopia in this case. The optic radiations carry nerve signals from the optic chiasm to the occipital lobe. Lesions in the inferior aspect of the optic radiation cause superior visual field defects, while lesions in the superior aspect of the optic radiation cause inferior visual field defects. Therefore, the lesion causing the superior homonymous quadrantanopia in this woman must be located in the inferior aspect of the optic radiation in the temporal lobe. Lesions compressing the lateral aspect of the optic chiasm cause nasal/binasal visual field defects, while lesions to the optic nerve before the optic chiasm result in an incongruous homonymous hemianopia affecting the same eye. Parietal lobe lesions can cause inferior homonymous quadrantanopias, but not superior homonymous quadrantanopias. Compression of the superior optic chiasm causes bitemporal hemianopias, not homonymous hemianopias.

      Understanding Visual Field Defects

      Visual field defects can occur due to various reasons, including lesions in the optic tract, optic radiation, or occipital cortex. A left homonymous hemianopia indicates a visual field defect to the left, which is caused by a lesion in the right optic tract. On the other hand, homonymous quadrantanopias can be categorized into PITS (Parietal-Inferior, Temporal-Superior) and can be caused by lesions in the inferior or superior optic radiations in the temporal or parietal lobes.

      When it comes to congruous and incongruous defects, the former refers to complete or symmetrical visual field loss, while the latter indicates incomplete or asymmetric visual field loss. Incongruous defects are caused by optic tract lesions, while congruous defects are caused by optic radiation or occipital cortex lesions. In cases where there is macula sparing, it is indicative of a lesion in the occipital cortex.

      Bitemporal hemianopia, on the other hand, is caused by a lesion in the optic chiasm. The type of defect can indicate the location of the compression, with an upper quadrant defect being more common in inferior chiasmal compression, such as a pituitary tumor, and a lower quadrant defect being more common in superior chiasmal compression, such as a craniopharyngioma.

      Understanding visual field defects is crucial in diagnosing and treating various neurological conditions. By identifying the type and location of the defect, healthcare professionals can provide appropriate interventions to improve the patient’s quality of life.

    • This question is part of the following fields:

      • Neurological System
      27.4
      Seconds
  • Question 23 - What is the primary function of zinc in the human body? ...

    Correct

    • What is the primary function of zinc in the human body?

      Your Answer: Antioxidant function

      Explanation:

      The Importance of Zinc in the Body

      Zinc is a vital mineral that plays various roles in the body. One of its essential functions is acting as an antioxidant, where it forms part of an enzyme complex that protects cell membranes from free radical damage. Additionally, zinc is involved in many enzyme reactions, including the production of hormones, DNA replication, and neurotransmitter metabolism. It also helps protect the body from toxins, heavy metals, and radiation.

      Furthermore, zinc is crucial in maintaining a healthy immune system, as it plays a role in both the antibody and cell-mediated immune responses. Unfortunately, zinc deficiency is relatively common among certain groups, such as women, children, the elderly, and pregnant patients. Vegetarians and chronic dieters may also experience mild zinc deficiency.

      To ensure adequate zinc intake, it is recommended to consume foods rich in zinc, such as liver, peas, pulses, meat, and wholemeal bread. By maintaining sufficient levels of zinc in the body, individuals can support their overall health and well-being.

    • This question is part of the following fields:

      • Clinical Sciences
      8.6
      Seconds
  • Question 24 - A 45-year-old carpenter comes to your medical practice complaining of weakness and numbness...

    Correct

    • A 45-year-old carpenter comes to your medical practice complaining of weakness and numbness in his right hand. During the examination, you observe a decrease in sensation on the palmar side of his index finger, middle finger, and the radial half of his ring finger. Tinel's sign is positive, leading you to diagnose carpal tunnel syndrome. Which nerve is the most probable cause of this condition?

      Your Answer: Median

      Explanation:

      The carpal tunnel only allows the median nerve to pass through it, providing sensory innervation to the palmar aspect of the thumb, index, middle, and radial aspect of the ring finger. If the median nerve is damaged, it can also cause weakness in wrist flexion.

      If any of the other nerves are affected, they would cause different patterns of sensory disturbance. For example, an ulnar nerve palsy would typically cause paresthesia on the ulnar half of the ring finger, the entire little finger, and the dorsal medial (ulnar) aspect of the hand. A radial nerve palsy would cause paresthesia on the dorsal lateral (radial) aspect of the hand, but not beyond the metacarpal-phalangeal joint. An axillary nerve palsy would only cause paresthesia in the deltoid area and not affect the sensation in the hands. Finally, a musculocutaneous nerve palsy would cause paresthesia along the lateral aspect of the forearm, but the sensation in the hand would remain intact.

      Carpal tunnel syndrome is a condition that occurs when the median nerve in the carpal tunnel is compressed. This can cause pain and pins and needles sensations in the thumb, index, and middle fingers. In some cases, the symptoms may even travel up the arm. Patients may shake their hand to alleviate the discomfort, especially at night. During an examination, weakness in thumb abduction and wasting of the thenar eminence may be observed. Tapping on the affected area may also cause paraesthesia, and flexing the wrist can trigger symptoms.

      There are several potential causes of carpal tunnel syndrome, including idiopathic factors, pregnancy, oedema, lunate fractures, and rheumatoid arthritis. Electrophysiology tests may reveal prolongation of the action potential in both motor and sensory nerves. Treatment options may include a six-week trial of conservative measures such as wrist splints at night or corticosteroid injections. If symptoms persist or are severe, surgical decompression may be necessary, which involves dividing the flexor retinaculum.

    • This question is part of the following fields:

      • Musculoskeletal System And Skin
      27.5
      Seconds
  • Question 25 - A 20-year-old woman comes to your general practice complaining of hearing difficulties for...

    Correct

    • A 20-year-old woman comes to your general practice complaining of hearing difficulties for the past month. She was previously diagnosed with tinnitus by one of your colleagues at the practice 11 months ago. The patient reports that she can hear better when outside but struggles in quiet environments. Upon otoscopy, no abnormalities are found. Otosclerosis is one of the differential diagnoses for this patient, which primarily affects the ossicle that connects to the cochlea. What is the name of the ossicle that attaches to the cochlea at the oval window?

      Your Answer: Stapes

      Explanation:

      The stapes bone is the correct answer.

      The ossicles are three bones located in the middle ear. They are arranged from lateral to medial and include the malleus, incus, and stapes. The malleus is the most lateral bone and its handle and lateral process attach to the tympanic membrane, making it visible on otoscopy. The head of the malleus articulates with the incus. The stapes bone is the most medial of the ossicles and is also known as the stirrup.

      Anatomy of the Ear

      The ear is divided into three distinct regions: the external ear, middle ear, and internal ear. The external ear consists of the auricle and external auditory meatus, which are innervated by the greater auricular nerve and auriculotemporal branch of the trigeminal nerve. The middle ear is the space between the tympanic membrane and cochlea, and is connected to the nasopharynx by the eustachian tube. The tympanic membrane is composed of three layers and is approximately 1 cm in diameter. The middle ear is innervated by the glossopharyngeal nerve. The ossicles, consisting of the malleus, incus, and stapes, transmit sound vibrations from the tympanic membrane to the inner ear. The internal ear contains the cochlea, which houses the organ of corti, the sense organ of hearing. The vestibule accommodates the utricule and saccule, which contain endolymph and are surrounded by perilymph. The semicircular canals, which share a common opening into the vestibule, lie at various angles to the petrous temporal bone.

    • This question is part of the following fields:

      • Respiratory System
      22.8
      Seconds
  • Question 26 - A 78-year-old man is involved in a car accident and suffers an injury...

    Correct

    • A 78-year-old man is involved in a car accident and suffers an injury to his sternum. He experiences tenderness around the manubriosternal joint.
      What is the classification of the manubriosternal joint?

      Your Answer: A symphysis

      Explanation:

      Types of Joints

      There are different types of joints in the human body. The manubriosternal joint is a secondary cartilaginous joint, also known as a symphysis. It has two articular surfaces covered with hyaline cartilage and connected by fibrocartilage. On the other hand, a double synovial joint has two separate synovial cavities separated by an articular disk that allows for flexibility and movement. An example of this is the Tempromandibular joint.

      Meanwhile, a fibrous joint is connected by fibrous tissue, mainly consisting of collagen, and is fixed. A primary cartilaginous joint is where two bones are joined by hyaline cartilage. Lastly, a single synovial joint is surrounded by a fibrous joint capsule that is continuous with the periosteum of the joined bones and contains synovial fluid.

      In summary, the different types of joints in the human body have varying structures and functions. these joints is essential in diagnosing and treating joint-related conditions.

    • This question is part of the following fields:

      • Clinical Sciences
      17.4
      Seconds
  • Question 27 - An 80-year-old woman arrives at the Emergency Department reporting painless loss of vision...

    Incorrect

    • An 80-year-old woman arrives at the Emergency Department reporting painless loss of vision on the right side that started 30 minutes ago. Based on the history and examination, it is probable that she has experienced an ophthalmic artery stroke. Which branch of the Circle of Willis is likely affected?

      Your Answer: Basilar artery

      Correct Answer: Internal carotid artery

      Explanation:

      The ophthalmic artery originates from the internal carotid artery, which is part of the Circle of Willis, a circular network of arteries that supply the brain. The anterior cerebral arteries, which supply the frontal and parietal lobes, as well as the corpus callosum and cingulate cortex of the brain, also arise from the internal carotid artery. A stroke of the ophthalmic artery or its branch, the central retinal artery, can cause painless loss of vision. The basilar artery, which forms part of the posterior cerebral circulation, is formed from the convergence of the two vertebral arteries and gives rise to many arteries, but not the ophthalmic artery. The posterior cerebral artery, which supplies the occipital lobe, arises from the basilar artery.

      The Circle of Willis is an anastomosis formed by the internal carotid arteries and vertebral arteries on the bottom surface of the brain. It is divided into two halves and is made up of various arteries, including the anterior communicating artery, anterior cerebral artery, internal carotid artery, posterior communicating artery, and posterior cerebral arteries. The circle and its branches supply blood to important areas of the brain, such as the corpus striatum, internal capsule, diencephalon, and midbrain.

      The vertebral arteries enter the cranial cavity through the foramen magnum and lie in the subarachnoid space. They then ascend on the anterior surface of the medulla oblongata and unite to form the basilar artery at the base of the pons. The basilar artery has several branches, including the anterior inferior cerebellar artery, labyrinthine artery, pontine arteries, superior cerebellar artery, and posterior cerebral artery.

      The internal carotid arteries also have several branches, such as the posterior communicating artery, anterior cerebral artery, middle cerebral artery, and anterior choroid artery. These arteries supply blood to different parts of the brain, including the frontal, temporal, and parietal lobes. Overall, the Circle of Willis and its branches play a crucial role in providing oxygen and nutrients to the brain.

    • This question is part of the following fields:

      • Cardiovascular System
      18.6
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  • Question 28 - A scan is being done on a foetus which is 34 weeks gestation....

    Correct

    • A scan is being done on a foetus which is 34 weeks gestation. The pancreas and its associated ducts are identified.

      What does the pancreatic duct in the foetus become in the adult?

      Your Answer: Ligamentum teres

      Explanation:

      The ligamentum teres in the adult is derived from the umbilical vein in the foetus.

      The Three Embryological Layers and their Corresponding Gastrointestinal Structures and Blood Supply

      The gastrointestinal system is a complex network of organs responsible for the digestion and absorption of nutrients. During embryonic development, the gastrointestinal system is formed from three distinct layers: the foregut, midgut, and hindgut. Each layer gives rise to specific structures and is supplied by a corresponding blood vessel.

      The foregut extends from the mouth to the proximal half of the duodenum and is supplied by the coeliac trunk. The midgut encompasses the distal half of the duodenum to the splenic flexure of the colon and is supplied by the superior mesenteric artery. Lastly, the hindgut includes the descending colon to the rectum and is supplied by the inferior mesenteric artery.

      Understanding the embryological origin and blood supply of the gastrointestinal system is crucial in diagnosing and treating gastrointestinal disorders. By identifying the specific structures and blood vessels involved, healthcare professionals can better target their interventions and improve patient outcomes.

    • This question is part of the following fields:

      • Gastrointestinal System
      34.2
      Seconds
  • Question 29 - A 32-year-old construction worker becomes dehydrated after spending the day working under the...

    Incorrect

    • A 32-year-old construction worker becomes dehydrated after spending the day working under the sun.

      What can be inferred about this person?

      Your Answer: Reduced activation of the renin-angiotensin-aldosterone system

      Correct Answer: Most of the ultrafiltrated water in the nephron to be reabsorbed in the proximal tubule

      Explanation:

      The majority of filtered water is absorbed in the proximal tubule, while the highest amount of sodium reabsorption occurs in this area due to the Na+/K+ ATPase mechanism. This results in the movement of fluid from the proximal tubules to peritubular capillaries.

      After a strenuous run, the individual is likely to be slightly dehydrated, leading to an increased activation of the renin-angiotensin-aldosterone system. This would cause an increase in aldosterone release from the zona glomerulosa. Additionally, vasopressin (also known as ADH) would be elevated to enhance water reabsorption in the collecting duct.

      Renal cortical blood flow is higher than medullary blood flow, as tubular cells are more susceptible to ischaemia.

      The Loop of Henle and its Role in Renal Physiology

      The Loop of Henle is a crucial component of the renal system, located in the juxtamedullary nephrons and running deep into the medulla. Approximately 60 litres of water containing 9000 mmol sodium enters the descending limb of the loop of Henle in 24 hours. The osmolarity of fluid changes and is greatest at the tip of the papilla. The thin ascending limb is impermeable to water, but highly permeable to sodium and chloride ions. This loss means that at the beginning of the thick ascending limb the fluid is hypo osmotic compared with adjacent interstitial fluid. In the thick ascending limb, the reabsorption of sodium and chloride ions occurs by both facilitated and passive diffusion pathways. The loops of Henle are co-located with vasa recta, which have similar solute compositions to the surrounding extracellular fluid, preventing the diffusion and subsequent removal of this hypertonic fluid. The energy-dependent reabsorption of sodium and chloride in the thick ascending limb helps to maintain this osmotic gradient. Overall, the Loop of Henle plays a crucial role in regulating the concentration of solutes in the renal system.

    • This question is part of the following fields:

      • Renal System
      26.9
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  • Question 30 - A 75-year-old man has recently been diagnosed with chronic myeloid leukaemia and is...

    Incorrect

    • A 75-year-old man has recently been diagnosed with chronic myeloid leukaemia and is undergoing chemotherapy. Following the start of treatment, he experiences acute renal failure and a significant increase in uric acid levels. What other electrolyte abnormality is likely to be present?

      Your Answer: Hypokalaemia

      Correct Answer: Hyperphosphataemia

      Explanation:

      The individual has been diagnosed with tumour lysis syndrome, which is a dangerous complication that can arise when commencing chemotherapy for cancer, particularly for lymphoma and leukaemia. Tumour lysis syndrome encompasses a range of metabolic imbalances, such as elevated levels of potassium, phosphates, and uric acid, as well as reduced levels of calcium. These imbalances can result in severe complications, including acute kidney failure, irregular heartbeats, and seizures.

      Understanding Tumour Lysis Syndrome

      Tumour lysis syndrome (TLS) is a life-threatening condition that can occur during the treatment of high-grade lymphomas and leukaemias. It is caused by the breakdown of tumour cells and the release of chemicals into the bloodstream. While it can occur without chemotherapy, it is usually triggered by the introduction of combination chemotherapy. Patients at high risk of TLS should be given prophylactic medication such as IV allopurinol or IV rasburicase to prevent the potentially deadly effects of tumour cell lysis.

      TLS leads to a high potassium and high phosphate level in the presence of a low calcium. It should be suspected in any patient presenting with an acute kidney injury in the presence of a high phosphate and high uric acid level. From 2004, TLS has been graded using the Cairo-Bishop scoring system, which takes into account laboratory and clinical factors.

      It is important to be aware of TLS and take preventative measures to avoid its potentially fatal consequences. By understanding the causes and symptoms of TLS, healthcare professionals can provide appropriate treatment and improve patient outcomes.

    • This question is part of the following fields:

      • Haematology And Oncology
      23.4
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SESSION STATS - PERFORMANCE PER SPECIALTY

General Principles (1/6) 17%
Neurological System (1/6) 17%
Psychiatry (1/1) 100%
Reproductive System (1/2) 50%
Clinical Sciences (2/3) 67%
Musculoskeletal System And Skin (1/5) 20%
Endocrine System (0/1) 0%
Haematology And Oncology (0/2) 0%
Respiratory System (1/1) 100%
Cardiovascular System (0/1) 0%
Gastrointestinal System (1/1) 100%
Renal System (0/1) 0%
Passmed