University:
Western Sydney University
Course:
MEDI 2003 | Clinical Sciences 2
Academic year:

2024
Views:

373

Pages:

2
Author:

Mariam A. A.

Respiratory Pathology Questions 1. Describe the pathophysiology of congenital central hypoventilation syndrome (3 marks) Answer: In this disease there is a mutation of the PHOX 2b transcription factor during the development of the central nervous system. As a result, this will lead to the formation of dysfunctional or a reduced number of PHOX 2b neurons. This will impair the communication between the peripheral and central chemoreceptors with the Pre-Box complex. This will lead to impaired ventilation, which may potentially cause hypoxemia and hypercapnia and eventually type 2 respiratory failure. 2. 3. Explain why a FEV1/FVC ratio of more than 70% alone is not a confirmation of a restrictive lung disease, rather it may only act as an “indicative”. (2 marks) Answer: This is because it can’t measure the thoracic volume. For example, you could have hyperinflation because of air trapping due to an obstructive lung disease. So, when you try to forcefully breath it all out you would not be able to because you have got something obstructing the airways. So, this will still give you a reduced forced vital capacity. 4. Asthma is a common disease experienced by many people. a. b. c. d. Why is asthma considered an obstructive lung disease. (1.5 marks) How would you test if a restrictive disease is caused due to asthma? (2 marks) Describe the pathogenesis of asthma (5 marks) Describe the mechanism of action of ONE relieving bronchodilator used in the treatment of asthma. (3 marks) e. Describe the mechanism of action of ONE preventing bronchodilator used in the treatment of asthma. (3 marks) Answer: Hello a. This is because in asthma there is a FVE1/FVC ratio of less than 70% because the airways. This is because the airways become narrowed and obstructed so it is harder for air to get out, but air entry may still somewhat remain normal because the lung tissue is usually fine, so the lung can still inflate to allow for more entry. b. I would give the patient a low dose of methacholine which is a histamine that even at low doses can cause constriction. If the FEV1 decreases by a lot, the asthma will be a very possible diagnosis. If not, then asthma becomes an unlikely diagnosis.