-
Question 1
Correct
-
A 75-year-old man presents to the Emergency Department with acute shortness of breath following a 4-day febrile illness. On initial assessment, his oxygen saturation is 70% on room air with a PaO2 of 4.2kpa on an arterial blood gas.
What would be the anticipated physiological response in this patient?Your Answer: Pulmonary artery vasoconstriction
Explanation:When faced with hypoxia, the pulmonary arteries undergo vasoconstriction, which redirects blood flow away from poorly oxygenated areas of the lungs and towards well-oxygenated regions. In cases where patients remain hypoxic despite optimal mechanical ventilation, inhaled nitric oxide can be used to induce pulmonary vasodilation and reverse this response.
The statement that increased tidal volume with decreased respiratory rate is a response to hypoxia is incorrect. While an increase in tidal volume may occur, it is typically accompanied by an increase in respiratory rate.
Pulmonary artery vasodilation is also incorrect. Hypoxia actually induces vasoconstriction in the pulmonary vasculature, as explained above.
Similarly, reduced tidal volume with increased respiratory rate is not a direct response to hypoxia. While respiratory rate may increase, tidal volumes typically increase in response to hypoxia.
In contrast to the pulmonary vessels, the systemic vasculature vasodilates in response to hypoxia.
The Effects of Hypoxia on Pulmonary Arteries
When the partial pressure of oxygen in the blood decreases, the pulmonary arteries undergo vasoconstriction. This means that the blood vessels narrow, allowing blood to be redirected to areas of the lung that are better aerated. This response is a natural mechanism that helps to improve the efficiency of gaseous exchange in the lungs. By diverting blood to areas with more oxygen, the body can ensure that the tissues receive the oxygen they need to function properly. Overall, hypoxia triggers a physiological response that helps to maintain homeostasis in the body.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 2
Incorrect
-
A 45-year-old man presents to the emergency department with fever, productive cough, and shortness of breath. He has no medical history and takes no regular medications.
Upon examination, coarse crackles and bronchial breathing are heard at the right lung base.
Chest radiography reveals consolidation in the lower right zone.
Arterial blood gas results are as follows:
pH 7.36 (7.35-7.45)
pO2 7.2 kPa (11-13)
pCO2 4.1 kPa (4-6)
SaO2 87% (94-98)
Based on the likely diagnosis, what is the expected initial physiological response?Your Answer:
Correct Answer: Vasoconstriction of the pulmonary arteries
Explanation:When hypoxia is present, the pulmonary arteries undergo vasoconstriction, which is the appropriate response. The patient is exhibiting symptoms of pneumonia and type 1 respiratory failure, as evidenced by clinical and radiographic findings. Vasoconstriction of the small pulmonary arteries helps to redirect blood flow from poorly ventilated regions of the lung to those with better ventilation, resulting in improved gas exchange efficiency between the alveoli and blood.
The Effects of Hypoxia on Pulmonary Arteries
When the partial pressure of oxygen in the blood decreases, the pulmonary arteries undergo vasoconstriction. This means that the blood vessels narrow, allowing blood to be redirected to areas of the lung that are better aerated. This response is a natural mechanism that helps to improve the efficiency of gaseous exchange in the lungs. By diverting blood to areas with more oxygen, the body can ensure that the tissues receive the oxygen they need to function properly. Overall, hypoxia triggers a physiological response that helps to maintain homeostasis in the body.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 3
Incorrect
-
A 28-year-old female patient presents to your clinic seeking help to quit smoking. Despite several attempts in the past, she has been unsuccessful. She has a medical history of bipolar disorder and well-managed epilepsy, for which she takes lamotrigine. She currently smokes 15 cigarettes per day and is especially interested in the health benefits of quitting smoking since she has recently found out that she is pregnant. As her physician, you decide to prescribe a suitable medication to assist her in her efforts. What would be the most appropriate treatment option?
Your Answer:
Correct Answer: Nicotine gum
Explanation:Standard treatments for nicotine dependence do not include amitriptyline, fluoxetine, or gabapentin. Nicotine replacement therapy (NRT) can be helpful for motivated patients, but it is not a cure for addiction and may require multiple attempts. Bupropion and varenicline are other smoking cessation aids, but they have multiple side effects and may not be suitable for all patients. NICE guidelines recommend discussing the best method of smoking cessation with the patient, but NRT is considered safer in pregnancy.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 4
Incorrect
-
Which one of the following is true regarding the phrenic nerves?
Your Answer:
Correct Answer: They both lie anterior to the hilum of the lungs
Explanation:The phrenic nerves, located in the anterior region of the lung’s hilum, play a crucial role in keeping the diaphragm functioning properly. These nerves have both sensory and motor functions, and any issues in the sub diaphragmatic area may result in referred pain in the shoulder.
The Phrenic Nerve: Origin, Path, and Supplies
The phrenic nerve is a crucial nerve that originates from the cervical spinal nerves C3, C4, and C5. It supplies the diaphragm and provides sensation to the central diaphragm and pericardium. The nerve passes with the internal jugular vein across scalenus anterior and deep to the prevertebral fascia of the deep cervical fascia.
The right phrenic nerve runs anterior to the first part of the subclavian artery in the superior mediastinum and laterally to the superior vena cava. In the middle mediastinum, it is located to the right of the pericardium and passes over the right atrium to exit the diaphragm at T8. On the other hand, the left phrenic nerve passes lateral to the left subclavian artery, aortic arch, and left ventricle. It passes anterior to the root of the lung and pierces the diaphragm alone.
Understanding the origin, path, and supplies of the phrenic nerve is essential in diagnosing and treating conditions that affect the diaphragm and pericardium.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 5
Incorrect
-
A 55-year-old woman comes to your clinic seeking help to quit smoking. She has been using nicotine patches for 6 months but has not been successful in her attempts. You decide to prescribe bupropion.
What is a typical side effect of bupropion?Your Answer:
Correct Answer: Gastrointestinal disturbance
Explanation:Side Effects of Buproprion
Buproprion is a medication that can cause aggression and hallucination in some patients. However, the more common side effects are gastrointestinal disturbances such as diarrhoea, nausea, and dry mouth. These side effects are often experienced by patients taking buproprion. It is important to be aware of the potential side effects of any medication and to speak with a healthcare provider if any concerns arise. Additional information on buproprion and its potential side effects can be found in the electronic Medicines Compendium and Medicines Complete.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 6
Incorrect
-
A 25-year-old female presents to the emergency department with complaints of shortness of breath that started 2 hours ago. She has no medical history. The results of her arterial blood gas (ABG) test are as follows:
Normal range
pH: 7.49 (7.35 - 7.45)
pO2: 12.2 (10 - 14)kPa
pCO2: 3.4 (4.5 - 6.0)kPa
HCO3: 22 (22 - 26)mmol/l
BE: +2 (-2 to +2)mmol/l
Her temperature is 37ºC, and her pulse is 98 beats/minute and regular. Based on this information, what is the most likely diagnosis?Your Answer:
Correct Answer: Anxiety hyperventilation
Explanation:The patient is exhibiting symptoms and ABG results consistent with respiratory alkalosis. However, it is important to conduct a thorough history and physical examination to rule out any underlying pulmonary pathology or infection. Based on the patient’s history, anxiety-induced hyperventilation is the most probable cause of her condition.
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.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 7
Incorrect
-
A 55-year-old woman comes to the clinic complaining of a persistent cough and increased production of sputum over the past year. She also reports feeling fatigued and experiencing shortness of breath. The patient mentions having had four chest infections in the last 12 months, all of which were treated with antibiotics. She has no medical or family history and has never smoked.
The healthcare provider suspects that bronchiectasis may be the underlying cause of her symptoms and orders appropriate tests, including a sputum sample.
What is the most likely organism to be identified?Your Answer:
Correct Answer:
Explanation:Bronchiectasis patients may have various bacteria present in their respiratory system, with Haemophilus influenzae and Pseudomonas aeruginosa being the most common. Staphylococcus aureus has also been found but not as frequently. Respiratory syncytial virus has not been detected in acute exacerbations of bronchiectasis. It is crucial to identify the specific bacteria causing exacerbations as antibiotic sensitivity patterns differ, and sputum culture results can impact the effectiveness of treatment. These findings are outlined in the British Thoracic Society’s guideline for non-CF bronchiectasis and a study by Metaxas et al. on the role of atypical bacteria and respiratory syncytial virus in bronchiectasis exacerbations.
Bronchiectasis is a condition where the airways become permanently dilated due to chronic inflammation or infection. Before treatment, it is important to identify any underlying causes that can be addressed, such as immune deficiencies. Management of bronchiectasis includes physical training, such as inspiratory muscle training, which has been shown to be effective for patients without cystic fibrosis. Postural drainage, antibiotics for exacerbations, and long-term rotating antibiotics for severe cases are also recommended. Bronchodilators may be used in selected cases, and immunizations are important to prevent infections. Surgery may be considered for localized disease. The most common organisms isolated from patients with bronchiectasis include Haemophilus influenzae, Pseudomonas aeruginosa, Klebsiella spp., and Streptococcus pneumoniae.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 8
Incorrect
-
Which one of the following would cause a rise in the carbon monoxide transfer factor (TLCO)?
Your Answer:
Correct Answer: Pulmonary haemorrhage
Explanation:When alveolar haemorrhage takes place, the TLCO typically rises as a result of the increased absorption of carbon monoxide by haemoglobin within the alveoli.
Understanding Transfer Factor in Lung Function Testing
The transfer factor is a measure of how quickly a gas diffuses from the alveoli into the bloodstream. This is typically tested using carbon monoxide, and the results can be given as either the total gas transfer (TLCO) or the transfer coefficient corrected for lung volume (KCO). A raised TLCO may be caused by conditions such as asthma, pulmonary haemorrhage, left-to-right cardiac shunts, polycythaemia, hyperkinetic states, male gender, or exercise. On the other hand, a lower TLCO may be indicative of pulmonary fibrosis, pneumonia, pulmonary emboli, pulmonary oedema, emphysema, anaemia, or low cardiac output.
KCO tends to increase with age, and certain conditions may cause an increased KCO with a normal or reduced TLCO. These conditions include pneumonectomy/lobectomy, scoliosis/kyphosis, neuromuscular weakness, and ankylosis of costovertebral joints (such as in ankylosing spondylitis). Understanding transfer factor is important in lung function testing, as it can provide valuable information about a patient’s respiratory health and help guide treatment decisions.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 9
Incorrect
-
A father brings his 5-year-old daughter to the GP with a 72-hour history of left ear pain. She has had a cough with coryzal symptoms for the past four days. She has no past medical history, allergies or current medications, and she is up-to-date with her vaccinations. Her temperature is 38.5ºC. No abnormality is detected on examination of the oral cavity. Following otoscopy, what is the most likely causative pathogen for her diagnosis of otitis media?
Your Answer:
Correct Answer: Streptococcus pneumoniae
Explanation:Otitis media is primarily caused by bacteria, with viral URTIs often preceding the infection. The majority of cases are secondary to bacterial infections, with the most common culprit being…
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.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 10
Incorrect
-
A 38-year-old man has been admitted to the ICU through the ED with reduced consciousness and cyanosis. Despite an oxygen saturation of 94% in the ED, both peripheral and central cyanosis were present. Arterial blood gas monitoring revealed significant hypoxia, but no evidence of methaemoglobin. The suspected diagnosis is carbon monoxide poisoning, and the patient is intubated and ventilated to prevent further leftward shift of the oxygen dissociation curve. What factors can cause this shift in the oxygen dissociation curve?
Your Answer:
Correct Answer: Hypocapnia
Explanation:The oxygen dissociation curve can be shifted to the left by low pCO2, which increases haemoglobin’s affinity for oxygen and makes it less likely to release oxygen to the tissues. In contrast, acidosis, hypercapnia, and hyperthermia cause a right shift of the curve, making it easier for oxygen to be released to the tissues. Raised levels of 2,3-diphosphoglycerate also shift the curve to the right by inhibiting oxygen binding to haemoglobin.
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.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 11
Incorrect
-
An 80-year-old man visits the GP clinic for a routine hearing examination. He reports a decline in hearing ability in his left ear for the past few months. After conducting Rinne and Weber tests, you determine that he has conductive hearing loss in the left ear. Upon otoscopy, you observe cerumen impaction.
What are the test findings for this patient?Your Answer:
Correct Answer: Rinne: bone conduction > air conduction in right ear; Weber: lateralising to right ear
Explanation: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.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 12
Incorrect
-
A 16-year-old male presents to the emergency department with a 48-hour history of tachypnea and tachycardia. His blood glucose level is 18mmol/l. While breathing 40% oxygen, an arterial blood sample is taken. The results show a PaO2 of 22kPa, pH of 7.35, PaCO2 of 3.5kPa, and HCO3- of 18.6 mmol/l. How should these blood gas results be interpreted?
Your Answer:
Correct Answer: Metabolic acidosis with full respiratory compensation
Explanation:The patient’s blood gas analysis shows a lower oxygen pressure by about 10kPa than the percentage of oxygen. The PaCo2 level is 3.5, indicating respiratory alkalosis or compensation for metabolic acidosis. The HCO3- level is 18.6, which suggests metabolic acidosis or metabolic compensation for respiratory alkalosis. These results indicate that the patient has metabolic acidosis with complete respiratory compensation. Additionally, the patient’s high blood glucose level suggests that the metabolic acidosis is due to diabetic ketoacidosis.
Arterial Blood Gas Interpretation: A 5-Step Approach
Arterial blood gas interpretation is a crucial aspect of patient care, particularly in critical care settings. The Resuscitation Council (UK) recommends a 5-step approach to interpreting arterial blood gas results. The first step is to assess the patient’s overall condition. The second step is to determine if the patient is hypoxaemic, with a PaO2 on air of less than 10 kPa. The third step is to assess if the patient is acidaemic (pH <7.35) or alkalaemic (pH >7.45).
The fourth step is to evaluate the respiratory component of the arterial blood gas results. A PaCO2 level greater than 6.0 kPa suggests respiratory acidosis, while a PaCO2 level less than 4.7 kPa suggests respiratory alkalosis. The fifth step is to assess the metabolic component of the arterial blood gas results. A bicarbonate level less than 22 mmol/l or a base excess less than -2mmol/l suggests metabolic acidosis, while a bicarbonate level greater than 26 mmol/l or a base excess greater than +2mmol/l suggests metabolic alkalosis.
To remember the relationship between pH, PaCO2, and bicarbonate, the acronym ROME can be used. Respiratory acidosis or alkalosis is opposite to the pH level, while metabolic acidosis or alkalosis is equal to the pH level. This 5-step approach and the ROME acronym can aid healthcare professionals in interpreting arterial blood gas results accurately and efficiently.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 13
Incorrect
-
A 6-year-old girl is playing with some small ball bearings. Regrettably, she inhales one. In which of the following lung regions is the ball expected to settle?
Your Answer:
Correct Answer: Right lower lobe
Explanation:Due to the angle of the right main bronchus from the trachea, small objects are more likely to get stuck in the most dependent part of the right lung. This makes the right lung the preferred location for most objects to enter.
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.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 14
Incorrect
-
What causes a cervical rib?
Your Answer:
Correct Answer: Elongation of the transverse processes of the 7th cervical vertebrae
Explanation:Cervical ribs are formed when the transverse process of the 7th cervical vertebrae becomes elongated, resulting in a fibrous band that connects to the first thoracic rib.
Cervical ribs are a rare anomaly that affects only 0.2-0.4% of the population. They are often associated with neurological symptoms and are caused by an anomalous fibrous band that originates from the seventh cervical vertebrae and may arc towards the sternum. While most cases are congenital and present around the third decade of life, some cases have been reported to occur following trauma. Bilateral cervical ribs are present in up to 70% of cases. Compression of the subclavian artery can lead to absent radial pulse and a positive Adsons test, which involves lateral flexion of the neck towards the symptomatic side and traction of the symptomatic arm. Treatment is usually only necessary when there is evidence of neurovascular compromise, and the traditional operative method for excision is a transaxillary approach.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 15
Incorrect
-
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:
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.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 16
Incorrect
-
A 49-year-old man experiences blunt force trauma to the head and subsequently experiences respiratory distress, leading to hypercapnia. What is the most probable consequence of this condition?
Your Answer:
Correct Answer: Cerebral vasodilation
Explanation:Cerebral vasodilation is a common result of hypercapnia, which can be problematic for patients with cranial trauma due to the potential increase in intracranial pressure.
Understanding the Monro-Kelly Doctrine and Autoregulation in the CNS
The Monro-Kelly doctrine governs the pressure within the cranium by considering the skull as a closed box. The loss of cerebrospinal fluid (CSF) can accommodate increases in mass until a critical point is reached, usually at 100-120ml of CSF lost. Beyond this point, intracranial pressure (ICP) rises sharply, and pressure will eventually equate with mean arterial pressure (MAP), leading to neuronal death and herniation.
The central nervous system (CNS) has the ability to autoregulate its own blood supply through vasoconstriction and dilation of cerebral blood vessels. However, extreme blood pressure levels can exceed this capacity, increasing the risk of stroke. Additionally, metabolic factors such as hypercapnia can cause vasodilation, which is crucial in ventilating head-injured patients.
It is important to note that the brain can only metabolize glucose, and a decrease in glucose levels can lead to impaired consciousness. Understanding the Monro-Kelly doctrine and autoregulation in the CNS is crucial in managing intracranial pressure and preventing neurological damage.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 17
Incorrect
-
A 59-year-old man comes to you with a dry cough that has been going on for three months and recent episodes of haemoptysis. He stopped smoking five years ago and has had two bouts of pneumonia in his left lower lobe in the last year. On examination, he is apyrexial and there are no notable findings.
What would be your first step in investigating this patient?Your Answer:
Correct Answer: Chest x ray
Explanation:Diagnosis of Bronchial Carcinoma
The patient’s medical history indicates the possibility of bronchial carcinoma. The most appropriate initial investigation to confirm this diagnosis is a chest x-ray. Other tests such as blood cultures may not be useful for an apyrexial patient. However, additional investigations may be considered after the chest x-ray. It is important to prioritize the chest x-ray as the first line investigation to detect any abnormalities in the lungs. Proper diagnosis is crucial for timely treatment and management of bronchial carcinoma.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 18
Incorrect
-
An 87-year-old man with a history of interstitial lung disease is admitted with fever, productive cough, and difficulty breathing. His inflammatory markers are elevated, and a chest x-ray reveals focal patchy consolidation in the right lung. He requires oxygen supplementation as his oxygen saturation level is 87% on room air. What factor causes a decrease in haemoglobin's affinity for oxygen?
Your Answer:
Correct Answer: Increase in temperature
Explanation:What effect does pyrexia have on the oxygen dissociation curve?
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.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 19
Incorrect
-
A 26-year-old man presents to the emergency department with a feeling of food stuck in his throat. He experienced this sensation 2 hours ago after consuming fish at a nearby seafood restaurant. The patient reports no breathing difficulties. Upon laryngoscopy, a fish bone is found lodged in the left piriform recess. While removing the fish bone, a nerve located deep to the mucosa covering the recess is damaged.
Which function is most likely to be affected in this individual?Your Answer:
Correct Answer: Cough reflex
Explanation:Foreign objects lodged in the piriform recess can cause damage to the internal laryngeal nerve, which is located just beneath a thin layer of mucosa covering the recess. This nerve plays a crucial role in the cough reflex, as it carries sensory information from the area above the vocal cords. Attempts to remove foreign objects from the piriform recess can also lead to nerve damage.
Other functions, such as mastication, the pharyngeal reflex, salivation, and taste sensation, are mediated by different nerves and are not directly related to the piriform recess or the internal laryngeal nerve.
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.
-
This question is part of the following fields:
- Respiratory System
-
-
Question 20
Incorrect
-
Which of the following laryngeal tumors is unlikely to spread to the cervical lymph nodes?
Your Answer:
Correct Answer: Glottic
Explanation:The area of the vocal cords lacks lymphatic drainage, making it a lymphatic boundary. The upper portion above the vocal cords drains to the deep cervical nodes through vessels that penetrate the thyrohyoid membrane. The lower portion below the vocal cords drains to the pre-laryngeal, pre-tracheal, and inferior deep cervical nodes. The aryepiglottic and vestibular folds have a significant lymphatic drainage and are prone to early metastasis.
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.
-
This question is part of the following fields:
- Respiratory System
-
00
Correct
00
Incorrect
00
:
00
:
00
Session Time
00
:
00
Average Question Time (
Secs)