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Question 1
Incorrect
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A patient is being anaesthetised for a minor bowel surgery. Sarah, a second year medical student is present and is asked to assist the anaesthetist during intubation. The anaesthetist inserts a laryngoscope in the patient's mouth and asks Sarah to identify the larynx.
Which one of the following anatomical landmarks corresponds to the position of the structure being identified by the student?Your Answer: C1-C2
Correct Answer: C3-C6
Explanation:The larynx is located in the front of the neck, specifically at the level of the vertebrae C3-C6. This area also includes important anatomical landmarks such as the Atlas and Axis vertebrae (C1-C2), the thyroid cartilage (C5), and the pulmonary hilum (T5-T7).
Anatomy of the Larynx
The larynx is located in the front of the neck, between the third and sixth cervical vertebrae. It is made up of several cartilaginous segments, including the paired arytenoid, corniculate, and cuneiform cartilages, as well as the single thyroid, cricoid, and epiglottic cartilages. The cricoid cartilage forms a complete ring. The laryngeal cavity extends from the laryngeal inlet to the inferior border of the cricoid cartilage and is divided into three parts: the laryngeal vestibule, the laryngeal ventricle, and the infraglottic cavity.
The vocal folds, also known as the true vocal cords, control sound production. They consist of the vocal ligament and the vocalis muscle, which is the most medial part of the thyroarytenoid muscle. The glottis is composed of the vocal folds, processes, and rima glottidis, which is the narrowest potential site within the larynx.
The larynx is also home to several muscles, including the posterior cricoarytenoid, lateral cricoarytenoid, thyroarytenoid, transverse and oblique arytenoids, vocalis, and cricothyroid muscles. These muscles are responsible for various actions, such as abducting or adducting the vocal folds and relaxing or tensing the vocal ligament.
The larynx receives its arterial supply from the laryngeal arteries, which are branches of the superior and inferior thyroid arteries. Venous drainage is via the superior and inferior laryngeal veins. Lymphatic drainage varies depending on the location within the larynx, with the vocal cords having no lymphatic drainage and the supraglottic and subglottic parts draining into different lymph nodes.
Overall, understanding the anatomy of the larynx is important for proper diagnosis and treatment of various conditions affecting this structure.
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This question is part of the following fields:
- Respiratory System
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Question 2
Correct
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A 25-year-old female patient visits your clinic complaining of hearing loss. According to her, her hearing has been declining for about two years, with her left ear being worse than the right. She struggles to hear her partner when he is on her left side. Additionally, she has been experiencing tinnitus in her left ear for a year. She mentions that her mother also has hearing difficulties and uses hearing aids on both ears. During the examination, the Rinne test shows a negative result on the left and a positive result on the right. On the other hand, the Weber test indicates that the sound is louder on the left. What is the probable impairment?
Your Answer: Conductive hearing loss on the left.
Explanation:Based on the results of the Weber and Rinne tests, the patient in the question is likely experiencing conductive hearing loss on the left side. The Weber test revealed that the patient hears sound better on the left side, which could indicate a conductive hearing loss or sensorineural hearing loss on the right side. However, the Rinne test was negative on the left side, indicating a conductive hearing loss. This is further supported by the patient’s reported symptoms of hearing loss in the left ear. This presentation, along with a family history of hearing loss, suggests a possible diagnosis of otosclerosis, a condition that affects the stapes bone and can lead to severe or total hearing loss.
Understanding the Different Causes of Deafness
Deafness can be caused by various factors, with ear wax, otitis media, and otitis externa being the most common. However, there are other conditions that can lead to hearing loss, each with its own characteristic features. Presbycusis, for instance, is age-related sensorineural hearing loss that often makes it difficult for patients to follow conversations. Otosclerosis, on the other hand, is an autosomal dominant condition that replaces normal bone with vascular spongy bone, causing conductive deafness, tinnitus, and a flamingo tinge in the tympanic membrane. Glue ear, also known as otitis media with effusion, is the most common cause of conductive hearing loss in children, while Meniere’s disease is characterized by recurrent episodes of vertigo, tinnitus, and sensorineural hearing loss. Drug ototoxicity, noise damage, and acoustic neuroma are other factors that can lead to deafness.
Understanding the different causes of deafness is crucial in diagnosing and treating the condition. By knowing the characteristic features of each condition, healthcare professionals can determine the appropriate interventions to help patients manage their hearing loss. It is also important for individuals to protect their hearing by avoiding exposure to loud noises and seeking medical attention when they experience any symptoms of hearing loss. With proper care and management, people with deafness can still lead fulfilling lives.
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This question is part of the following fields:
- Respiratory System
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Question 3
Correct
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A 26-year-old man has been experiencing a chronic cough and wheeze since starting a new job. He has noticed that his peak flow measurements are significantly reduced while at work but improve on the weekends. What substance is commonly linked to this type of asthma?
Your Answer: Isocyanates
Explanation:Occupational Asthma: Causes and Symptoms
Occupational asthma is a type of asthma that is caused by exposure to certain chemicals in the workplace. Patients may experience worsening asthma symptoms while at work or notice an improvement in symptoms when away from work. The most common cause of occupational asthma is exposure to isocyanates, which are found in spray painting and foam moulding using adhesives. Other chemicals associated with occupational asthma include platinum salts, soldering flux resin, glutaraldehyde, flour, epoxy resins, and proteolytic enzymes.
To diagnose occupational asthma, it is recommended to measure peak expiratory flow at work and away from work. If there is a significant difference in peak expiratory flow, referral to a respiratory specialist is necessary. Treatment may include avoiding exposure to the triggering chemicals and using medications to manage asthma symptoms. It is important for employers to provide a safe working environment and for employees to report any concerns about potential exposure to harmful chemicals.
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This question is part of the following fields:
- Respiratory System
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Question 4
Incorrect
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As the pregnancy progresses, at what stage does the foetus typically begin producing surfactant?
A mother has been informed that she will have to deliver her baby prematurely due to complications in the pregnancy. To decrease the chances of neonatal distress syndrome, doctors have administered steroids to stimulate surfactant production in the foetus. They clarify that the foetus is already generating its own surfactant, and these steroids will enhance the process.Your Answer: Week 30
Correct Answer: Week 22
Explanation:Lung development in humans begins at week 4 with the formation of the respiratory diverticulum. By week 10, the lungs start to grow as tertiary bronchial buds form. Terminal bronchioles begin to form around week 18. The saccular stage of lung development, which marks the earliest viability for a human fetus, occurs at around 22-24 weeks when type 2 alveolar cells start producing surfactant. By week 30, the primary alveoli form as the mesenchyme surrounding the lungs becomes highly vascular.
The Importance of Pulmonary Surfactant in Breathing
Pulmonary surfactant is a substance composed of phospholipids, carbohydrates, and proteins that is released by type 2 pneumocytes. Its main component, dipalmitoyl phosphatidylcholine (DPPC), plays a crucial role in reducing alveolar surface tension. This substance is first detectable around 28 weeks and increases in concentration as the alveoli decrease in size. This helps prevent the alveoli from collapsing and reduces the muscular force needed to expand the lungs, ultimately decreasing the work of breathing. Additionally, pulmonary surfactant lowers the elastic recoil at low lung volumes, preventing the alveoli from collapsing at the end of each expiration. Overall, pulmonary surfactant is essential in maintaining proper lung function and preventing respiratory distress.
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This question is part of the following fields:
- Respiratory System
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Question 5
Correct
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A 63-year-old man visits his GP complaining of worsening shortness of breath. He was diagnosed with COPD six years ago and has been frequently admitted to the emergency department due to lower respiratory tract infections, especially in the past year. He has a smoking history of 50 pack-years and currently smokes 20 cigarettes per day.
During the examination, the patient appears to be struggling to breathe even at rest and is in the tripod position. His heart rate is 78/min, blood pressure is 140/88 mmHg, oxygen saturation is 88% on air, respiratory rate is 26 breaths per minute, and temperature is 36.4ºC. His chest expansion is symmetrical, and breath sounds are equal throughout the lung fields.
Recent spirometry results show that his FEV1 was 47% a week ago, 53% a month ago, and 67% six months ago. What intervention would be most effective in slowing the decline of his FEV1?Your Answer: Smoking cessation
Explanation:Slowing the decrease in FEV1 in COPD can be most effectively achieved by quitting smoking.
The National Institute for Health and Care Excellence (NICE) updated its guidelines on the management of chronic obstructive pulmonary disease (COPD) in 2018. The guidelines recommend general management strategies such as smoking cessation advice, annual influenzae vaccination, and one-off pneumococcal vaccination. Pulmonary rehabilitation is also recommended for patients who view themselves as functionally disabled by COPD.
Bronchodilator therapy is the first-line treatment for patients who remain breathless or have exacerbations despite using short-acting bronchodilators. The next step is determined by whether the patient has asthmatic features or features suggesting steroid responsiveness. NICE suggests several criteria to determine this, including a previous diagnosis of asthma or atopy, a higher blood eosinophil count, substantial variation in FEV1 over time, and substantial diurnal variation in peak expiratory flow.
If the patient does not have asthmatic features or features suggesting steroid responsiveness, a long-acting beta2-agonist (LABA) and long-acting muscarinic antagonist (LAMA) should be added. If the patient is already taking a short-acting muscarinic antagonist (SAMA), it should be discontinued and switched to a short-acting beta2-agonist (SABA). If the patient has asthmatic features or features suggesting steroid responsiveness, a LABA and inhaled corticosteroid (ICS) should be added. If the patient remains breathless or has exacerbations, triple therapy (LAMA + LABA + ICS) should be offered.
NICE only recommends theophylline after trials of short and long-acting bronchodilators or to people who cannot use inhaled therapy. Azithromycin prophylaxis is recommended in select patients who have optimised standard treatments and continue to have exacerbations. Mucolytics should be considered in patients with a chronic productive cough and continued if symptoms improve.
Cor pulmonale features include peripheral oedema, raised jugular venous pressure, systolic parasternal heave, and loud P2. Loop diuretics should be used for oedema, and long-term oxygen therapy should be considered. Smoking cessation, long-term oxygen therapy in eligible patients, and lung volume reduction surgery in selected patients may improve survival in patients with stable COPD. NICE does not recommend the use of ACE-inhibitors, calcium channel blockers, or alpha blockers
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This question is part of the following fields:
- Respiratory System
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Question 6
Correct
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A 44-year-old woman is scheduled for a thyroidectomy due to symptomatic tracheal compression. She has a history of hyperthyroidism that was controlled with carbimazole. However, she was deemed a suitable candidate for thyroidectomy after presenting to the emergency department with dyspnoea and stridor.
As a surgical resident assisting the ENT surgeon, you need to ligate the superior thyroid artery before removing the thyroid glands to prevent excessive bleeding. However, the superior laryngeal artery, a branch of the superior thyroid artery, is closely related to a structure that, if injured, can lead to loss of sensation in the laryngeal mucosa.
What is the correct identification of this structure?Your Answer: Internal laryngeal nerve
Explanation:The internal laryngeal nerve and the superior laryngeal artery are closely associated with each other. The superior laryngeal artery travels alongside the internal laryngeal branch of the superior laryngeal nerve, beneath the thyrohyoid muscle. It originates from the superior thyroid artery near its separation from the external carotid artery.
If the internal laryngeal nerve is damaged, it can result in a loss of sensation to the laryngeal mucosa. The nerve is situated beneath the mucous membrane of the piriform recess, making it vulnerable to injury from sharp objects like fish and chicken bones that may become stuck in the recess.
Anatomy of the Larynx
The larynx is located in the front of the neck, between the third and sixth cervical vertebrae. It is made up of several cartilaginous segments, including the paired arytenoid, corniculate, and cuneiform cartilages, as well as the single thyroid, cricoid, and epiglottic cartilages. The cricoid cartilage forms a complete ring. The laryngeal cavity extends from the laryngeal inlet to the inferior border of the cricoid cartilage and is divided into three parts: the laryngeal vestibule, the laryngeal ventricle, and the infraglottic cavity.
The vocal folds, also known as the true vocal cords, control sound production. They consist of the vocal ligament and the vocalis muscle, which is the most medial part of the thyroarytenoid muscle. The glottis is composed of the vocal folds, processes, and rima glottidis, which is the narrowest potential site within the larynx.
The larynx is also home to several muscles, including the posterior cricoarytenoid, lateral cricoarytenoid, thyroarytenoid, transverse and oblique arytenoids, vocalis, and cricothyroid muscles. These muscles are responsible for various actions, such as abducting or adducting the vocal folds and relaxing or tensing the vocal ligament.
The larynx receives its arterial supply from the laryngeal arteries, which are branches of the superior and inferior thyroid arteries. Venous drainage is via the superior and inferior laryngeal veins. Lymphatic drainage varies depending on the location within the larynx, with the vocal cords having no lymphatic drainage and the supraglottic and subglottic parts draining into different lymph nodes.
Overall, understanding the anatomy of the larynx is important for proper diagnosis and treatment of various conditions affecting this structure.
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This question is part of the following fields:
- Respiratory System
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Question 7
Correct
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A 19-year-old male presents to the emergency department with complaints of breathing difficulty. Upon examination, his chest appears normal, but his respiratory rate is 32 breaths per minute. The medical team suspects he may be experiencing a panic attack and subsequent hyperventilation. What impact will this have on his blood gas levels?
Your Answer: Respiratory alkalosis
Explanation:The patient is experiencing a respiratory alkalosis due to their hyperventilation, which is causing a decrease in carbon dioxide levels and resulting in an alkaline state.
Respiratory Alkalosis: Causes and Examples
Respiratory alkalosis is a condition that occurs when the blood pH level rises above the normal range due to excessive breathing. This can be caused by various factors, including anxiety, pulmonary embolism, CNS disorders, altitude, and pregnancy. Salicylate poisoning can also lead to respiratory alkalosis, but it may also cause metabolic acidosis in the later stages. In this case, the respiratory centre is stimulated early, leading to respiratory alkalosis, while the direct acid effects of salicylates combined with acute renal failure may cause acidosis later on. It is important to identify the underlying cause of respiratory alkalosis to determine the appropriate treatment. Proper management can help prevent complications and improve the patient’s overall health.
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This question is part of the following fields:
- Respiratory System
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Question 8
Incorrect
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A 35-year-old female presents with recurrent episodes of severe vertigo that have been disabling. She experiences these episodes multiple times a day, with each one lasting for about 10-20 minutes. Along with the vertigo, she also experiences ringing in both ears, nausea, and vomiting. She has noticed a change in her hearing in both ears, with difficulty hearing at times and normal hearing at other times. Additionally, she reports increased pressure in her ears. During the examination, you notice a painless rash behind her ear that has been present for many years.
What is the most likely diagnosis?Your Answer: Vestibular neuronitis
Correct Answer: Meniere’s disease
Explanation:Suspect Meniere’s disease in a patient presenting with vertigo, tinnitus, and fluctuating sensorineural hearing loss. Acoustic neuroma would present with additional symptoms such as facial numbness and loss of corneal reflex. Herpes Zoster Oticus (Ramsey Hunt syndrome) would present with facial palsy and a painless rash. Vestibular neuronitis would have longer episodes of vertigo, nausea, and vomiting, but no hearing loss. Benign paroxysmal positional vertigo would have brief episodes of vertigo after sudden head movements.
Meniere’s disease is a condition that affects the inner ear and its cause is unknown. It is more commonly seen in middle-aged adults but can occur at any age and affects both men and women equally. The condition is characterized by the excessive pressure and progressive dilation of the endolymphatic system. The main symptoms of Meniere’s disease are recurrent episodes of vertigo, tinnitus, and sensorineural hearing loss. Vertigo is usually the most prominent symptom, but patients may also experience a sensation of aural fullness or pressure, nystagmus, and a positive Romberg test. These episodes can last from minutes to hours and are typically unilateral, but bilateral symptoms may develop over time.
The natural history of Meniere’s disease is that symptoms usually resolve in the majority of patients after 5-10 years. However, most patients will be left with some degree of hearing loss, and psychological distress is common. ENT assessment is required to confirm the diagnosis, and patients should inform the DVLA as the current advice is to cease driving until satisfactory control of symptoms is achieved. Acute attacks can be managed with buccal or intramuscular prochlorperazine, and admission to the hospital may be required. Prevention strategies include the use of betahistine and vestibular rehabilitation exercises, which may be beneficial.
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This question is part of the following fields:
- Respiratory System
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Question 9
Incorrect
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A 30-year-old woman comes to see her GP with persistent tinnitus and hearing loss in both ears. This is her first time experiencing these symptoms, but she mentions that her older sister has had similar issues. During the examination, the doctor notices a pinkish hue to her eardrums. Audiometry tests confirm that she has conductive deafness. What is the most probable diagnosis?
Your Answer: Meniere's disease
Correct Answer: Otosclerosis
Explanation:Nausea and vomiting often accompany migraines, which are characterized by severe headaches that can last for hours or even days. Other symptoms may include sensitivity to light and sound, as well as visual disturbances such as flashing lights or blind spots. Migraines can be triggered by a variety of factors, including stress, certain foods, hormonal changes, and changes in sleep patterns. Treatment options may include medication, lifestyle changes, and alternative therapies.
Understanding Otosclerosis: A Progressive Conductive Deafness
Otosclerosis is a medical condition that occurs when normal bone is replaced by vascular spongy bone. This condition leads to a progressive conductive deafness due to the fixation of the stapes at the oval window. It is an autosomal dominant condition that typically affects young adults, with onset usually occurring between the ages of 20-40 years.
The main features of otosclerosis include conductive deafness, tinnitus, a normal tympanic membrane, and a positive family history. In some cases, patients may also experience a flamingo tinge, which is caused by hyperemia and affects around 10% of patients.
Management of otosclerosis typically involves the use of a hearing aid or stapedectomy. A hearing aid can help to improve hearing, while a stapedectomy involves the surgical removal of the stapes bone and replacement with a prosthesis.
Overall, understanding otosclerosis is important for individuals who may be at risk of developing this condition. Early diagnosis and management can help to improve hearing and prevent further complications.
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This question is part of the following fields:
- Respiratory System
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Question 10
Incorrect
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A premature baby is born and the anaesthetists are struggling to ventilate the lungs because of insufficient surfactant. How does Laplace's law explain the force pushing inwards on the walls of the alveolus caused by surface tension between two static fluids, such as air and water in the alveolus?
Your Answer: Proportional to the fourth power of the radius of the alveolus
Correct Answer: Inversely proportional to the radius of the alveolus
Explanation:The Relationship between Alveolar Size and Surface Tension in Respiratory Physiology
In respiratory physiology, the alveolus is often represented as a perfect sphere to apply Laplace’s law. According to this law, there is an inverse relationship between the size of the alveolus and the surface tension. This means that smaller alveoli experience greater force than larger alveoli for a given surface tension, and they will collapse first. This phenomenon explains why, when two balloons are attached together by their ends, the smaller balloon will empty into the bigger balloon.
In the lungs, this same principle applies to lung units, causing atelectasis and collapse when surfactant is not present. Surfactant is a substance that reduces surface tension, making it easier to expand the alveoli and preventing smaller alveoli from collapsing. Therefore, surfactant plays a crucial role in maintaining the proper functioning of the lungs and preventing respiratory distress. the relationship between alveolar size and surface tension is essential in respiratory physiology and can help in the development of treatments for lung diseases.
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This question is part of the following fields:
- Respiratory System
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Question 11
Correct
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A 36-year-old man presents to his GP with symptoms of vertigo. He reports that he has been experiencing constant dizziness for the past 2 days, which has prevented him from going to work. He also reports hearing difficulties and tinnitus in his right ear, as well as nausea and difficulty with balance. He notes that these symptoms are not related to changes in position. He has no significant medical history, except for a recent bout of flu that resolved on its own.
During the examination, the man is observed to sway to the right while attempting to walk in a straight line. He also has a positive head thrust test to the right side. A complete neurological examination is performed, and aside from mild sensorineural hearing loss in the right ear, his neurological function is normal.
Which structures are most likely involved in this man's condition?Your Answer: Vestibular nerve and labyrinth
Explanation:The patient is displaying symptoms of labyrinthitis, which affects both the vestibular nerve and labyrinth, resulting in vertigo and hearing impairment. In contrast, pure vestibular neuritis only causes vestibular symptoms without affecting hearing. Benign paroxysmal positional vertigo (BPPV) involves otolith displacement and is triggered by head position changes, which is not the case for this patient’s constant vertigo. Facial nerve palsy primarily causes facial drooping and does not affect hearing or vestibular function, making it an unlikely diagnosis for this patient.
Understanding Viral Labyrinthitis
Labyrinthitis is a condition that affects the membranous labyrinth, which includes the vestibular and cochlear end organs. It can be caused by a viral or bacterial infection, or it may be associated with systemic diseases. Viral labyrinthitis is the most common form of the condition.
It’s important to distinguish labyrinthitis from vestibular neuritis, which only affects the vestibular nerve and doesn’t cause hearing impairment. Labyrinthitis, on the other hand, affects both the vestibular nerve and the labyrinth, resulting in both vertigo and hearing loss.
The condition typically affects people between the ages of 40 and 70 and is characterized by an acute onset of symptoms, including vertigo, nausea and vomiting, hearing loss, and tinnitus. Patients may also experience gait disturbance and fall towards the affected side.
Diagnosis is based on a patient’s history and examination, which may reveal spontaneous unidirectional horizontal nystagmus towards the unaffected side, sensorineural hearing loss, and an abnormal head impulse test.
While episodes of labyrinthitis are usually self-limiting, medications like prochlorperazine or antihistamines may help reduce the sensation of dizziness. Understanding the symptoms and management of viral labyrinthitis can help patients seek appropriate treatment and manage their condition effectively.
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This question is part of the following fields:
- Respiratory System
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Question 12
Incorrect
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A 70-year-old man with lung cancer is having a left pneumonectomy. The left main bronchus is being divided. Which thoracic vertebrae is located behind this structure?
Your Answer: T1
Correct Answer: T6
Explanation:Anatomy of the Lungs
The lungs are a pair of organs located in the chest cavity that play a vital role in respiration. The right lung is composed of three lobes, while the left lung has two lobes. The apex of both lungs is approximately 4 cm superior to the sternocostal joint of the first rib. The base of the lungs is in contact with the diaphragm, while the costal surface corresponds to the cavity of the chest. The mediastinal surface contacts the mediastinal pleura and has the cardiac impression. The hilum is a triangular depression above and behind the concavity, where the structures that form the root of the lung enter and leave the viscus. The right main bronchus is shorter, wider, and more vertical than the left main bronchus. The inferior borders of both lungs are at the 6th rib in the mid clavicular line, 8th rib in the mid axillary line, and 10th rib posteriorly. The pleura runs two ribs lower than the corresponding lung level. The bronchopulmonary segments of the lungs are divided into ten segments, each with a specific function.
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This question is part of the following fields:
- Respiratory System
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Question 13
Correct
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A 65-year-old man presents with a persistent dry cough and unintentional weight loss of 5kg over the past 3 months. He denies experiencing chest pain, dyspnoea, fever or haemoptysis. The patient has a history of smoking 10 cigarettes a day for the last 50 years and has been diagnosed with COPD. A nodule is detected on chest x-ray, and biopsy results indicate a tumour originating from the bronchial glands.
What is the most probable diagnosis?Your Answer: Adenocarcinoma of the lung
Explanation:Adenocarcinoma has become the most prevalent form of lung cancer, originating from the bronchial glands as a type of non-small-cell lung cancer.
While a bronchogenic cyst may cause chest pain and dysphagia, it is typically diagnosed during childhood and does not stem from the bronchial glands.
Sarcoidosis may result in a persistent cough and weight loss, but it typically affects multiple systems and does not involve nodules originating from the bronchial glands.
Small cell carcinoma of the lung is a significant consideration, but given the description of a tumor originating from the bronchial glands, adenocarcinoma is the more probable diagnosis.
Lung cancer can be classified into two main types: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). SCLC is less common, accounting for only 15% of cases, but has a worse prognosis. NSCLC, on the other hand, is more prevalent and can be further broken down into different subtypes. Adenocarcinoma is now the most common type of lung cancer, likely due to the increased use of low-tar cigarettes. It is often seen in non-smokers and accounts for 62% of cases in ‘never’ smokers. Squamous cell carcinoma is another subtype, and cavitating lesions are more common in this type of lung cancer. Large cell carcinoma, alveolar cell carcinoma, bronchial adenoma, and carcinoid are other subtypes of NSCLC. Differentiating between these subtypes is crucial as different drugs are available to treat each subtype.
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This question is part of the following fields:
- Respiratory System
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Question 14
Incorrect
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Sophie, a 4-year-old patient with Down's syndrome, is brought to the general practitioner by her father. He is worried as Sophie has been crying more than usual and has started holding her right ear. She is diagnosed with acute bacterial otitis media.
What is the most probable bacteria responsible for this infection?Your Answer: Treponema pallidum
Correct Answer: Haemophilus influenzae
Explanation:Haemophilus influenzae is a frequent culprit behind bacterial otitis media, a common ear infection.
The majority of cases of acute bacterial otitis media are caused by Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella.
Genital gonorrhoeae is caused by N. gonorrhoeae, a sexually transmitted infection that presents with discharge and painful urination.
Meningococcal sepsis, a life-threatening condition, is caused by N. meningitides.
Staph. aureus is responsible for superficial skin infections like impetigo.
Syphilis, which typically manifests as a painless genital sore called a chancre, is caused by T. pallidum.
Acute otitis media is a common condition in young children, often caused by bacterial infections following viral upper respiratory tract infections. Symptoms include ear pain, fever, and hearing loss, and diagnosis is based on criteria such as the presence of a middle ear effusion and inflammation of the tympanic membrane. Antibiotics may be prescribed in certain cases, and complications can include perforation of the tympanic membrane, hearing loss, and more serious conditions such as meningitis and brain abscess.
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This question is part of the following fields:
- Respiratory System
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Question 15
Correct
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A 60-year-old diabetic patient presents to the clinic with a chief complaint of hearing loss. After conducting a Webber’s and Rinne’s test, the following results were obtained:
- Webber’s test: lateralizes to the left ear
- Rinne’s test (left ear): bone conduction > air conduction
- Rinne’s test (right ear): air conduction > bone conduction
Based on these findings, what is the probable cause of the patient's hearing loss?Your Answer: Otitis media with effusion
Explanation:The Weber test lateralises to the side with bone conduction > air conduction, indicating conductive hearing loss on that side. The options given include acoustic neuroma (sensorineural hearing loss), otitis media with effusion (conductive hearing loss), temporal lobe epilepsy (no conductive hearing loss), and Meniere’s disease (vertigo, tinnitus, and fluctuating hearing loss). The correct answer is otitis media with effusion.
Rinne’s and Weber’s Test for Differentiating Conductive and Sensorineural Deafness
Rinne’s and Weber’s tests are used to differentiate between conductive and sensorineural deafness. Rinne’s test involves placing a tuning fork over the mastoid process until the sound is no longer heard, then repositioning it just over the external acoustic meatus. A positive test indicates that air conduction (AC) is better than bone conduction (BC), while a negative test indicates that BC is better than AC, suggesting conductive deafness.
Weber’s test involves placing a tuning fork in the middle of the forehead equidistant from the patient’s ears and asking the patient which side is loudest. In unilateral sensorineural deafness, sound is localized to the unaffected side, while in unilateral conductive deafness, sound is localized to the affected side.
The table below summarizes the interpretation of Rinne and Weber tests. A normal result indicates that AC is greater than BC bilaterally and the sound is midline. Conductive hearing loss is indicated by BC being greater than AC in the affected ear and AC being greater than BC in the unaffected ear, with the sound lateralizing to the affected ear. Sensorineural hearing loss is indicated by AC being greater than BC bilaterally, with the sound lateralizing to the unaffected ear.
Overall, Rinne’s and Weber’s tests are useful tools for differentiating between conductive and sensorineural deafness, allowing for appropriate management and treatment.
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This question is part of the following fields:
- Respiratory System
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Question 16
Incorrect
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What is the accurate embryonic source of the stapes?
Your Answer: First pharyngeal arch
Correct Answer: Second pharyngeal arch
Explanation:The stapes, which is a cartilaginous element in the ear, originates from the ectoderm covering the outer aspect of the second pharyngeal arch. This strip of ectoderm is located lateral to the metencephalic neural fold. Reicherts cartilage, which extends from the otic capsule to the midline on each side, is responsible for the formation of the stapes. The cartilages of the first and second pharyngeal arches articulate superior to the tubotympanic recess, with the malleus, incus, and stapes being formed from these cartilages. While the malleus is mostly formed from the first arch, the stapes is most likely to arise from the second arch.
The Development and Contributions of Pharyngeal Arches
During the fourth week of embryonic growth, a series of mesodermal outpouchings develop from the pharynx, forming the pharyngeal arches. These arches fuse in the ventral midline, while pharyngeal pouches form on the endodermal side between the arches. There are six pharyngeal arches, with the fifth arch not contributing any useful structures and often fusing with the sixth arch.
Each pharyngeal arch has its own set of muscular and skeletal contributions, as well as an associated endocrine gland, artery, and nerve. The first arch contributes muscles of mastication, the maxilla, Meckel’s cartilage, and the incus and malleus bones. The second arch contributes muscles of facial expression, the stapes bone, and the styloid process and hyoid bone. The third arch contributes the stylopharyngeus muscle, the greater horn and lower part of the hyoid bone, and the thymus gland. The fourth arch contributes the cricothyroid muscle, all intrinsic muscles of the soft palate, the thyroid and epiglottic cartilages, and the superior parathyroids. The sixth arch contributes all intrinsic muscles of the larynx (except the cricothyroid muscle), the cricoid, arytenoid, and corniculate cartilages, and is associated with the pulmonary artery and recurrent laryngeal nerve.
Overall, the development and contributions of pharyngeal arches play a crucial role in the formation of various structures in the head and neck region.
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This question is part of the following fields:
- Respiratory System
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Question 17
Incorrect
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A 6-month-old infant is brought to the paediatrician due to increased work of breathing. The infant was born at term and via spontaneous vaginal delivery 6 months ago.
During the examination, the paediatrician observes moderate subcostal and intercostal recession and notes that the infant appears tachypnoeic. The infant's temperature is 38.9ºC, and a chest x-ray is ordered, which reveals some consolidation in the right lower zone. Broad-spectrum antibiotics are initiated.
Upon reviewing the infant's oxygen dissociation curve, the paediatrician notes a leftward shift relative to the standard adult curve. What is the cause of this appearance in the infant's oxygen dissociation curve?Your Answer: Increased concentration of 2,3-diphosphoglycerate (2,3-DPG)
Correct Answer: Foetal haemoglobin (HbF)
Explanation:The factor that shifts the oxygen dissociation curve to the left is foetal haemoglobin (HbF). This is because HbF has a higher affinity for oxygen than adult haemoglobin, haemoglobin A, which allows maternal haemoglobin to preferentially offload oxygen to the foetus across the placenta.
Understanding the Oxygen Dissociation Curve
The oxygen dissociation curve is a graphical representation of the relationship between the percentage of saturated haemoglobin and the partial pressure of oxygen in the blood. It is not influenced by the concentration of haemoglobin. The curve can shift to the left or right, indicating changes in oxygen delivery to tissues. When the curve shifts to the left, there is increased saturation of haemoglobin with oxygen, resulting in decreased oxygen delivery to tissues. Conversely, when the curve shifts to the right, there is reduced saturation of haemoglobin with oxygen, leading to enhanced oxygen delivery to tissues.
The L rule is a helpful mnemonic to remember the factors that cause a shift to the left, resulting in lower oxygen delivery. These factors include low levels of hydrogen ions (alkali), low partial pressure of carbon dioxide, low levels of 2,3-diphosphoglycerate, and low temperature. On the other hand, the mnemonic ‘CADET, face Right!’ can be used to remember the factors that cause a shift to the right, leading to raised oxygen delivery. These factors include carbon dioxide, acid, 2,3-diphosphoglycerate, exercise, and temperature.
Understanding the oxygen dissociation curve is crucial in assessing the oxygen-carrying capacity of the blood and the delivery of oxygen to tissues. By knowing the factors that can shift the curve to the left or right, healthcare professionals can make informed decisions in managing patients with respiratory and cardiovascular diseases.
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This question is part of the following fields:
- Respiratory System
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Question 18
Correct
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A 27-year-old woman, who has had eczema and asthma since childhood, comes for her yearly asthma check-up. She has been using her salbutamol inhaler more frequently over the last 3 months and is concerned that it may be due to getting a new kitten. In allergic asthma, which cell is present in excessive amounts?
Your Answer: Eosinophils
Explanation:The patient’s medical background indicates that she may have atopic asthma. It is probable that her symptoms have worsened and she has had to use more salbutamol reliever due to an allergy to her new kitten’s animal dander.
Individuals with allergic asthma have been found to have increased levels of eosinophils in their airways. The severity of asthma is linked to the number of eosinophils present, as they contribute to long-term airway inflammation by causing damage, blockages, and hyperresponsiveness.
The immediate symptoms of asthma after exposure are caused by mast cell degranulation.
Asthma is a common respiratory disorder that affects both children and adults. It is characterized by chronic inflammation of the airways, resulting in reversible bronchospasm and airway obstruction. While asthma can develop at any age, it typically presents in childhood and may improve or resolve with age. However, it can also persist into adulthood and cause significant morbidity, with around 1,000 deaths per year in the UK.
Several risk factors can increase the likelihood of developing asthma, including a personal or family history of atopy, antenatal factors such as maternal smoking or viral infections, low birth weight, not being breastfed, exposure to allergens and air pollution, and the hygiene hypothesis. Patients with asthma may also suffer from other atopic conditions such as eczema and hay fever, and some may be sensitive to aspirin. Occupational asthma is also a concern for those exposed to allergens in the workplace.
Symptoms of asthma include coughing, dyspnea, wheezing, and chest tightness, with coughing often worse at night. Signs may include expiratory wheezing on auscultation and reduced peak expiratory flow rate. Diagnosis is typically made through spirometry, which measures the volume and speed of air during exhalation and inhalation.
Management of asthma typically involves the use of inhalers to deliver drug therapy directly to the airways. Short-acting beta-agonists such as salbutamol are the first-line treatment for relieving symptoms, while inhaled corticosteroids like beclometasone dipropionate and fluticasone propionate are used for daily maintenance therapy. Long-acting beta-agonists like salmeterol and leukotriene receptor antagonists like montelukast may also be used in combination with other medications. Maintenance and reliever therapy (MART) is a newer approach that combines ICS and a fast-acting LABA in a single inhaler for both daily maintenance and symptom relief. Recent guidelines recommend offering a leukotriene receptor antagonist instead of a LABA for patients on SABA + ICS whose asthma is not well controlled, and considering MART for those with poorly controlled asthma.
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This question is part of the following fields:
- Respiratory System
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Question 19
Incorrect
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A 67-year-old man has been diagnosed with stage III lung cancer and is concerned about potential complications. What are the risks he may face?
Your Answer: Asthma
Correct Answer: Pneumothorax
Explanation:Pneumothorax is more likely to occur in individuals with lung cancer.
Pneumothorax: Characteristics and Risk Factors
Pneumothorax is a medical condition characterized by the presence of air in the pleural cavity, which is the space between the lungs and the chest wall. This condition can occur spontaneously or as a result of trauma or medical procedures. There are several risk factors associated with pneumothorax, including pre-existing lung diseases such as COPD, asthma, cystic fibrosis, lung cancer, and Pneumocystis pneumonia. Connective tissue diseases like Marfan’s syndrome and rheumatoid arthritis can also increase the risk of pneumothorax. Ventilation, including non-invasive ventilation, can also be a risk factor.
Symptoms of pneumothorax tend to come on suddenly and can include dyspnoea, chest pain (often pleuritic), sweating, tachypnoea, and tachycardia. In some cases, catamenial pneumothorax can be the cause of spontaneous pneumothoraces occurring in menstruating women. This type of pneumothorax is thought to be caused by endometriosis within the thorax. Early diagnosis and treatment of pneumothorax are crucial to prevent complications and improve outcomes.
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This question is part of the following fields:
- Respiratory System
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Question 20
Incorrect
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A 49-year-old man comes to the clinic with recent onset of asthma and frequent nosebleeds. Laboratory results reveal elevated eosinophil counts and a positive pANCA test.
What is the probable diagnosis?Your Answer: Temporal arteritis
Correct Answer: Eosinophilic granulomatosis with polyangiitis (EGPA)
Explanation:The presence of adult-onset asthma, eosinophilia, and a positive pANCA test strongly suggests a diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA) in this patient.
Although GPA can cause epistaxis, the absence of other characteristic symptoms such as saddle-shaped nose deformity, haemoptysis, renal failure, and positive cANCA make EGPA a more likely diagnosis.
Polyarteritis Nodosa, Temporal Arteritis, and Toxic Epidermal Necrolysis have distinct clinical presentations that do not match the symptoms exhibited by this patient.
Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome)
Eosinophilic granulomatosis with polyangiitis (EGPA), previously known as Churg-Strauss syndrome, is a type of small-medium vessel vasculitis that is associated with ANCA. It is characterized by asthma, blood eosinophilia (more than 10%), paranasal sinusitis, mononeuritis multiplex, and pANCA positivity in 60% of cases.
Compared to granulomatosis with polyangiitis, EGPA is more likely to have blood eosinophilia and asthma as prominent features. Additionally, leukotriene receptor antagonists may trigger the onset of the disease.
Overall, EGPA is a rare but serious condition that requires prompt diagnosis and treatment to prevent complications.
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This question is part of the following fields:
- Respiratory System
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Question 21
Incorrect
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Which of the following paraneoplastic manifestations is the LEAST frequent in individuals diagnosed with squamous cell lung carcinoma?
Your Answer: Hyperthyroidism
Correct Answer: Lambert-Eaton syndrome
Explanation:Small cell lung cancer is strongly associated with Lambert-Eaton syndrome, while squamous cell lung cancer is more commonly associated with paraneoplastic features such as PTHrp, clubbing, and HPOA.
Lung cancer can present with paraneoplastic features, which are symptoms caused by the cancer but not directly related to the tumor itself. Small cell lung cancer can cause the secretion of ADH and, less commonly, ACTH, which can lead to hypertension, hyperglycemia, hypokalemia, alkalosis, and muscle weakness. Lambert-Eaton syndrome is also associated with small cell lung cancer. Squamous cell lung cancer can cause the secretion of parathyroid hormone-related protein, leading to hypercalcemia, as well as clubbing and hypertrophic pulmonary osteoarthropathy. Adenocarcinoma can cause gynecomastia and hypertrophic pulmonary osteoarthropathy. Hypertrophic pulmonary osteoarthropathy is a painful condition involving the proliferation of periosteum in the long bones. Although traditionally associated with squamous cell carcinoma, some studies suggest that adenocarcinoma is the most common cause.
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This question is part of the following fields:
- Respiratory System
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Question 22
Correct
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A 55-year-old man comes to the hospital complaining of lethargy, headache, and shortness of breath. Upon examination, he is found to be cyanotic and hypoxic, and is admitted to the respiratory ward for oxygen therapy.
Following some initial tests, the consultant informs the patient that his hemoglobin has a high affinity for oxygen, resulting in reduced oxygen delivery to the tissues.
What is the probable reason for this alteration in the oxygen dissociation curve?Your Answer: Low 2,3-DPG
Explanation:The correct answer is low 2,3-DPG. The professor’s description refers to a left shift in the oxygen dissociation curve, which indicates that haemoglobin has a high affinity for oxygen and is less likely to release it to the tissues. Factors that cause a left shift include low temperature, high pH, low PCO2, and low 2,3-DPG. 2,3-DPG is a substance that helps release oxygen from haemoglobin, so low levels of it result in less oxygen being released, causing a left shift in the oxygen dissociation curve.
The answer high temperature is incorrect because it causes a right shift in the oxygen dissociation curve, promoting oxygen delivery to the tissues. Hypercapnoea also causes a right shift in the curve, promoting oxygen delivery. Hyperglycaemia has no effect on haemoglobin’s ability to release oxygen, so it is also incorrect.
Understanding the Oxygen Dissociation Curve
The oxygen dissociation curve is a graphical representation of the relationship between the percentage of saturated haemoglobin and the partial pressure of oxygen in the blood. It is not influenced by the concentration of haemoglobin. The curve can shift to the left or right, indicating changes in oxygen delivery to tissues. When the curve shifts to the left, there is increased saturation of haemoglobin with oxygen, resulting in decreased oxygen delivery to tissues. Conversely, when the curve shifts to the right, there is reduced saturation of haemoglobin with oxygen, leading to enhanced oxygen delivery to tissues.
The L rule is a helpful mnemonic to remember the factors that cause a shift to the left, resulting in lower oxygen delivery. These factors include low levels of hydrogen ions (alkali), low partial pressure of carbon dioxide, low levels of 2,3-diphosphoglycerate, and low temperature. On the other hand, the mnemonic ‘CADET, face Right!’ can be used to remember the factors that cause a shift to the right, leading to raised oxygen delivery. These factors include carbon dioxide, acid, 2,3-diphosphoglycerate, exercise, and temperature.
Understanding the oxygen dissociation curve is crucial in assessing the oxygen-carrying capacity of the blood and the delivery of oxygen to tissues. By knowing the factors that can shift the curve to the left or right, healthcare professionals can make informed decisions in managing patients with respiratory and cardiovascular diseases.
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This question is part of the following fields:
- Respiratory System
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Question 23
Incorrect
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Mrs. Johnson is an 82-year-old woman who visited her General practitioner complaining of gradual worsening shortness of breath over the past two months. During the medical history, it was discovered that she has had Chronic Obstructive Pulmonary Disease (COPD) for 20 years.
Upon examination, there are no breath sounds at both lung bases and a stony dull note to percussion over the same areas. Based on this clinical scenario, what is the probable cause of her recent exacerbation of shortness of breath?Your Answer:
Correct Answer: Pleural transudate effusion secondary to cor pulmonale
Explanation:The most likely cause of a pleural transudate is heart failure. This is due to the congestion of blood into the systemic venous circulation, which can result from long-standing COPD and increase in pulmonary vascular resistance leading to right-sided heart failure or cor pulmonale. Other options such as infective exacerbation of COPD or pulmonary edema secondary to heart failure are less likely to explain the clinical signs. Pleural exudate effusion secondary to cor pulmonale is also not the most appropriate answer as it would cause a transudate pleural effusion, not an exudate.
Understanding the Causes and Features of Pleural Effusion
Pleural effusion is a medical condition characterized by the accumulation of fluid in the pleural space, which is the area between the lungs and the chest wall. The causes of pleural effusion can be classified into two types: transudate and exudate. Transudate is characterized by a protein concentration of less than 30g/L and is commonly caused by heart failure, hypoalbuminemia, liver disease, and other conditions. On the other hand, exudate is characterized by a protein concentration of more than 30g/L and is commonly caused by infections, pneumonia, tuberculosis, and other conditions.
The symptoms of pleural effusion may include dyspnea, non-productive cough, and chest pain. Upon examination, patients may exhibit dullness to percussion, reduced breath sounds, and reduced chest expansion. It is important to identify the underlying cause of pleural effusion to determine the appropriate treatment plan. Early diagnosis and treatment can help prevent complications and improve the patient’s overall health.
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This question is part of the following fields:
- Respiratory System
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Question 24
Incorrect
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Control of ventilation. Which statement is false?
Your Answer:
Correct Answer: Central chemoreceptors respond to changes in O2
Explanation:The central chemoreceptors increase ventilation in response to an increase in H+ in the brain interstitial fluid.
The Control of Ventilation in the Human Body
The control of ventilation in the human body is a complex process that involves various components working together to regulate the respiratory rate and depth of respiration. The respiratory centres, chemoreceptors, lung receptors, and muscles all play a role in this process. The automatic, involuntary control of respiration occurs from the medulla, which is responsible for controlling the respiratory rate and depth of respiration.
The respiratory centres consist of the medullary respiratory centre, apneustic centre, and pneumotaxic centre. The medullary respiratory centre has two groups of neurons, the ventral group, which controls forced voluntary expiration, and the dorsal group, which controls inspiration. The apneustic centre, located in the lower pons, stimulates inspiration and activates and prolongs inhalation. The pneumotaxic centre, located in the upper pons, inhibits inspiration at a certain point and fine-tunes the respiratory rate.
Ventilatory variables, such as the levels of pCO2, are the most important factors in ventilation control, while levels of O2 are less important. Peripheral chemoreceptors, located in the bifurcation of carotid arteries and arch of the aorta, respond to changes in reduced pO2, increased H+, and increased pCO2 in arterial blood. Central chemoreceptors, located in the medulla, respond to increased H+ in brain interstitial fluid to increase ventilation. It is important to note that the central receptors are not influenced by O2 levels.
Lung receptors also play a role in the control of ventilation. Stretch receptors respond to lung stretching, causing a reduced respiratory rate, while irritant receptors respond to smoke, causing bronchospasm. J (juxtacapillary) receptors are also involved in the control of ventilation. Overall, the control of ventilation is a complex process that involves various components working together to regulate the respiratory rate and depth of respiration.
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This question is part of the following fields:
- Respiratory System
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Question 25
Incorrect
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An 85-year-old woman visits her doctor with a complaint of worsening breathlessness in the past 6 months. She has been smoking 10 cigarettes a day for the last 40 years. The doctor suspects that she may have chronic obstructive pulmonary disease. What is one of the mechanisms by which smoking damages the lungs and leads to emphysema?
Your Answer:
Correct Answer: Inactivation of alpha-1 antitrypsin
Explanation:The function of alpha-1 antitrypsin is to inhibit elastase. However, smoke has a negative impact on this protein in the lungs, resulting in increased activity of elastases and the breakdown of elastic tissue, which leads to emphysema.
Contrary to popular belief, smoke actually activates polymorphonuclear leucocytes, which contributes to the development of emphysema.
Mucous gland hyperplasia, basal cell metaplasia, and basement membrane thickening are all examples of how smoke affects the lungs to cause chronic bronchitis, not emphysema.
COPD, or chronic obstructive pulmonary disease, can be caused by a variety of factors. The most common cause is smoking, which can lead to inflammation and damage in the lungs over time. Another potential cause is alpha-1 antitrypsin deficiency, a genetic condition that can result in lung damage. Additionally, exposure to certain substances such as cadmium (used in smelting), coal, cotton, cement, and grain can also contribute to the development of COPD. It is important to identify and address these underlying causes in order to effectively manage and treat COPD.
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This question is part of the following fields:
- Respiratory System
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Question 26
Incorrect
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A 54-year-old man complains of facial pain and discomfort during meals. He has been experiencing halitosis and a dry mouth. Additionally, he has a lump under his left mandible. What is the probable underlying diagnosis?
Your Answer:
Correct Answer: Stone impacted in Whartons duct
Explanation:The signs are indicative of sialolithiasis, which usually involves the formation of stones in the submandibular gland and can block Wharton’s duct. Stensen’s duct, on the other hand, is responsible for draining the parotid gland.
Diseases of the Submandibular Glands
The submandibular glands are responsible for producing mixed seromucinous secretions, which can range from more serous to more mucinous depending on parasympathetic activity. These glands secrete approximately 800-1000ml of saliva per day, with parasympathetic fibers derived from the chorda tympani nerves and the submandibular ganglion. However, several conditions can affect the submandibular glands.
One such condition is sialolithiasis, which occurs when salivary gland calculi form in the submandibular gland. These stones are usually composed of calcium phosphate or calcium carbonate and can cause colicky pain and postprandial swelling of the gland. Sialography is used to investigate the site of obstruction and associated stones, with impacted stones in the distal aspect of Wharton’s duct potentially removed orally. However, other stones and chronic inflammation may require gland excision.
Sialadenitis is another condition that can affect the submandibular glands, usually as a result of Staphylococcus aureus infection. This can cause pus to leak from the duct and erythema to be noted. A submandibular abscess may develop, which is a serious complication as it can spread through other deep fascial spaces and occlude the airway.
Finally, submandibular tumors can also affect these glands, with only 8% of salivary gland tumors affecting the submandibular gland. Of these, 50% are malignant, usually adenoid cystic carcinoma. Diagnosis usually involves fine needle aspiration cytology, with imaging using CT and MRI. Due to the high prevalence of malignancy, all masses of the submandibular glands should generally be excised.
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This question is part of the following fields:
- Respiratory System
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Question 27
Incorrect
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A patient in their 60s presents to surgical outpatients with diffuse abdominal pain. As a second-line imaging investigation, a CT scan is requested. The radiologist looks through the images to write the report. Which of the following would they expect to find at the level of the transpyloric plane (L1)?
Your Answer:
Correct Answer: Hila of the kidneys
Explanation:The hila of the kidneys are at the level of the transpyloric plane, with the left kidney slightly higher than the right. The adrenal glands sit just above the kidneys at the level of T12. The neck of the pancreas, not the body, is at the level of the transpyloric plane. The coeliac trunk originates at the level of T12 and the inferior mesenteric artery originates at L3.
The Transpyloric Plane and its Anatomical Landmarks
The transpyloric plane is an imaginary horizontal line that passes through the body of the first lumbar vertebrae (L1) and the pylorus of the stomach. It is an important anatomical landmark used in clinical practice to locate various organs and structures in the abdomen.
Some of the structures that lie on the transpyloric plane include the left and right kidney hilum (with the left one being at the same level as L1), the fundus of the gallbladder, the neck of the pancreas, the duodenojejunal flexure, the superior mesenteric artery, and the portal vein. The left and right colic flexure, the root of the transverse mesocolon, and the second part of the duodenum also lie on this plane.
In addition, the upper part of the conus medullaris (the tapered end of the spinal cord) and the spleen are also located on the transpyloric plane. Knowing the location of these structures is important for various medical procedures, such as abdominal surgeries and diagnostic imaging.
Overall, the transpyloric plane serves as a useful reference point for clinicians to locate important anatomical structures in the abdomen.
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This question is part of the following fields:
- Respiratory System
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Question 28
Incorrect
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An 80-year-old woman presents to the emergency department with a 2-day history of severe abdominal pain, accompanied by nausea and vomiting. Upon examination, she has a distended abdomen that is tender to the touch, and bowel sounds are infrequent. Her medical history includes a hysterectomy and cholecystectomy. A CT scan is ordered, which reveals a bowel obstruction at the L1 level. What is the most likely affected area?
Your Answer:
Correct Answer: Duodenum
Explanation:The 2nd segment of the duodenum is situated at the transpyloric plane, which corresponds to the level of L1 and is a significant anatomical reference point.
The Transpyloric Plane and its Anatomical Landmarks
The transpyloric plane is an imaginary horizontal line that passes through the body of the first lumbar vertebrae (L1) and the pylorus of the stomach. It is an important anatomical landmark used in clinical practice to locate various organs and structures in the abdomen.
Some of the structures that lie on the transpyloric plane include the left and right kidney hilum (with the left one being at the same level as L1), the fundus of the gallbladder, the neck of the pancreas, the duodenojejunal flexure, the superior mesenteric artery, and the portal vein. The left and right colic flexure, the root of the transverse mesocolon, and the second part of the duodenum also lie on this plane.
In addition, the upper part of the conus medullaris (the tapered end of the spinal cord) and the spleen are also located on the transpyloric plane. Knowing the location of these structures is important for various medical procedures, such as abdominal surgeries and diagnostic imaging.
Overall, the transpyloric plane serves as a useful reference point for clinicians to locate important anatomical structures in the abdomen.
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This question is part of the following fields:
- Respiratory System
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Question 29
Incorrect
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A 65-year-old man visits his doctor complaining of a productive cough and difficulty breathing for the past 10 days. The doctor prescribes antibiotics, but after a week, the patient's symptoms persist and he develops a fever and pain when breathing in. The doctor orders a chest x-ray, which indicates the presence of an empyema. What is the probable causative agent responsible for this condition?
Your Answer:
Correct Answer: Streptococcus pneumoniae
Explanation:An accumulation of pus in the pleural space, known as empyema, is a possible complication of pneumonia and is responsible for the patient’s pleurisy. Streptococcus pneumoniae, the most frequent cause of pneumonia, is also the leading cause of empyema.
Pneumonia is a common condition that affects the alveoli of the lungs, usually caused by a bacterial infection. Other causes include viral and fungal infections. Streptococcus pneumoniae is the most common organism responsible for pneumonia, accounting for 80% of cases. Haemophilus influenzae is common in patients with COPD, while Staphylococcus aureus often occurs in patients following influenzae infection. Mycoplasma pneumoniae and Legionella pneumophilia are atypical pneumonias that present with dry cough and other atypical symptoms. Pneumocystis jiroveci is typically seen in patients with HIV. Idiopathic interstitial pneumonia is a group of non-infective causes of pneumonia.
Patients who develop pneumonia outside of the hospital have community-acquired pneumonia (CAP), while those who develop it within hospitals are said to have hospital-acquired pneumonia. Symptoms of pneumonia include cough, sputum, dyspnoea, chest pain, and fever. Signs of systemic inflammatory response, tachycardia, reduced oxygen saturations, and reduced breath sounds may also be present. Chest x-ray is used to diagnose pneumonia, with consolidation being the classical finding. Blood tests, such as full blood count, urea and electrolytes, and CRP, are also used to check for infection.
Patients with pneumonia require antibiotics to treat the underlying infection and supportive care, such as oxygen therapy and intravenous fluids. Risk stratification is done using a scoring system called CURB-65, which stands for confusion, respiration rate, blood pressure, age, and is used to determine the management of patients with community-acquired pneumonia. Home-based care is recommended for patients with a CRB65 score of 0, while hospital assessment is recommended for all other patients, particularly those with a CRB65 score of 2 or more. The CURB-65 score also correlates with an increased risk of mortality at 30 days.
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This question is part of the following fields:
- Respiratory System
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Question 30
Incorrect
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A 26-year-old woman comes to your clinic complaining of feeling dizzy for the past two days. She describes a sensation of the room spinning and has been experiencing nausea. The dizziness is relieved when she lies down and has no apparent triggers. She denies any hearing loss or aural fullness and is otherwise healthy. Upon examination, she has no fever and otoscopy reveals no abnormalities. You suspect she may have viral labyrinthitis and prescribe prochlorperazine to alleviate her vertigo symptoms. What class of antiemetic does prochlorperazine belong to?
Your Answer:
Correct Answer: Dopamine receptor antagonist
Explanation:Prochlorperazine belongs to a class of drugs known as dopamine receptor antagonists, which work by inhibiting stimulation of the chemoreceptor trigger zone (CTZ) through D2 receptors. Other drugs in this class include domperidone, metoclopramide, and olanzapine.
Antihistamine antiemetics, such as cyclizine and promethazine, are H1 histamine receptor antagonists.
5-HT3 receptor antagonists, such as ondansetron and granisetron, are effective both centrally and peripherally. They work by blocking serotonin receptors in the central nervous system and gastrointestinal tract.
Antimuscarinic antiemetics are anticholinergic drugs, with hyoscine (scopolamine) being a common example.
Vertigo is a condition characterized by a false sensation of movement in the body or environment. There are various causes of vertigo, each with its own unique characteristics. Viral labyrinthitis, for example, is typically associated with a recent viral infection, sudden onset, nausea and vomiting, and possible hearing loss. Vestibular neuronitis, on the other hand, is characterized by recurrent vertigo attacks lasting hours or days, but with no hearing loss. Benign paroxysmal positional vertigo is triggered by changes in head position and lasts for only a few seconds. Meniere’s disease, meanwhile, is associated with hearing loss, tinnitus, and a feeling of fullness or pressure in the ears. Elderly patients with vertigo may be experiencing vertebrobasilar ischaemia, which is accompanied by dizziness upon neck extension. Acoustic neuroma, which is associated with hearing loss, vertigo, and tinnitus, is also a possible cause of vertigo. Other causes include posterior circulation stroke, trauma, multiple sclerosis, and ototoxicity from medications like gentamicin.
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This question is part of the following fields:
- Respiratory System
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