Anatomy+ Embryology
Name the three pathways (hiatus) that pass through the diaphragm, mention their position
T8- Caval hiatus
T10- Oesophageal hiatus
T12- Aortic hiatus
What is COPD? Differentiate the two main conditions it primarily encompasses
COPD is a progressive, inflammatory lung disease that causes obstructed airflow from the lungs . It encompass chronic bronchitis and emphysema.
Chronic bronchitis mainly involves airway inflammation and excess mucus production in the bronchi and bronchioles, while emphysema mainly involves destruction of alveolar walls and loss of elastic recoil
What is hypersensitivity
undesirable, exaggerated, or inappropriate immune system responses to harmless substances, or heightened neurological responses to physical or emotional stimuli. Rather than protecting the body, these overreactions cause tissue damage, inflammation, or significant discomfort
What are the roles of investigations in asthma?
Access severity, monitor progression, identify complications, exclude other diagnoses.
List three structures involved in upper respiratory tract infections
Nose, Sinuses(maxillary, ethmoid, frontal, sphenoid), Pharynx, Larynx, Middle ear
Mention two anatomical spaces where fluid is most like to collect
costodiaphragmatic recess
costomediastinal recess
In the practical, how does the plastic disc simulate asthma, and what happens to the Flow-Volume plot?
The small hole in the plastic disc physically increases airflow resistance, perfectly mimicking the bronchoconstriction and airway resistance seen in asthma
. On a Flow-Volume plot, this obstruction causes a blunted (lower) PEF and a characteristic "scooped out" (concave) expiratory curve
What is structural violence and how does poverty contribute to Mrs Parker’s thought of her family’s health
Structural violence is the social structures that disadvantage certain groups of people and increase their risk of getting an illness. Mrs Parker stayed in a BNG house, a small house with a family of 5 and was in a low social class which made her think that improving her family’s housing conditions and social class would improve her health.
What do you see in an ABG test in a patient with mild asthma and why?
Decreased PaCO2 due to hyperventilation, resulting in respiratory alkalosis.
Mention the structures that make up the conducting zone and respiratory zone in order and mention the function of these two zones.
Conducting zone includes: nose, trachea, primary bronchi, secondary bronchi, tertiary bronchi, conducting bronchiole, terminal bronchiole. This zone is for filtering, warming, moistening and conducting air to the lungs
Respiratory zone includes: respiratory bronchiole, alveolar duct, alveoli. This zone is for gaseous exchange
What is the clinical relevance of lateral folding and what does a defect in the folding cause?
Why do Cindy's airways compress during forced expiration, and how does spirometry prove her treatment works?
To force air out against high resistance, Cindy must strenuously contract her expiratory muscles
. This creates massive positive pressure in the chest that actively squeezes and compresses her inflamed airways, trapping air and dropping flow rates
. To prove her treatment works, Dr Nel tests for reversibility: he compares her spirometry before and after administering a bronchodilator via nebuliser
. A significant improvement in her FEV-1 and PEF confirms the medication has successfully opened the airways.
What role does IL-5 play in asthma?
What is the difference between controllers and relievers? Mention atleast one class of medication for each
Controllers reduce long-term inflammation and severity/frequency of exacerbations. Includes Inhaled corticosteroids, long-acting B2 agonists (LABAs), leukotriene receptor antagonists(LRAs)
relievers reduce acute symptoms and exacerbations in the short-term by relaxing airway muscle. Includes short-acting B2 agonists(SABAs), short-acting muscarinic antagonist
Name two viral and two bacterial causes of respiratory tract infections
Viral causes (Rhinovirus, Influenza virus, Adenovirus)
Bacterial causes (Group A Streptococcus, Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, Bordetella pertussis, Pseudomonas aeruginosa)
After week 5–6 of development, the lungs are present but not fully mature and must undergo further maturation up to 7–8 years. Relate the stages of lung maturation to Neonatal Respiratory Distress Syndrome (NRDS).
Lung maturation involves several stages: pseudoglandular, canalicular, saccular, and alveolar stages. Surfactant production begins in the late canalicular stage and becomes sufficient in the saccular stage (around 24–34 weeks gestation). In Neonatal Respiratory Distress Syndrome (NRDS), prematurity leads to insufficient surfactant production due to immature type II pneumocytes. This causes increased alveolar surface tension, alveolar collapse (atelectasis), decreased lung compliance, and impaired gas exchange, resulting in hypoxia and respiratory distress in the newborn.
Explain the pathophysiology of chronic bronchitis
Chronic irritant exposure such as cigarette smoking causes inflammation of the bronchi and bronchioles by neutrophils, macrophages and CD8⁺ T cells. This leads to oedema, thickening of airway walls and mucus hypersecretion due to goblet cell hyperplasia and enlargement of mucus glands. Excess mucus forms plugs and obstructs airways causing increased airway resistance and difficulty with expiration. Poor ventilation of alveoli leads to V/Q mismatch, hypoxaemia and eventually hypercapnia. Chronic hypoxia may also cause pulmonary hypertension and cor pulmonale
What is the most common inhalant allergen in atopic asthma, explain how it causes bronchoconstriction
House dust mite: When inhaled, dust mites are recognized by IgE antibodies (Type 1 hypersensitivity reaction). Mast cells will degranulate; histamine and leukotrienes are releases causing contraction of bronchial smooth muscle leading to narrowing of the airways, increased airway resistance and difficulty with expiration. This results in wheezing, dyspnoea and chest tightness. Air trapping and hyperinflation may also occur due to collapse of narrowed airways during expiration
What is you see in an ABG test in a patient with severe asthma and why is it an issue?
Normal or high PaCO2. This is an issue as it is a sign of impending respiratory failure, as asthmatics should be hyperventilating. The increase is due to decreased respiratory function.
Explain how a defective CFTR (cystic fibrosis transmembrane conductance regulator) result in airway obstruction.
Tip: start with a normal CFTR and then the defective CFTR
Normal CFTR: chloride is secreted into the airway lumen where water follows to form a thin, watery mucus which is easy to clear along with bacteria and debris that is attached to it.
Defective CFTR: Chloride gets stuck inside the cells on airways, causing absorption of sodium and water molecules. This creates thick, sticky mucus which results in airway obstruction (along with recurrent lung infection and brochiectasis)
Relate the concept of Tracheoesophageal fistula (abnormal connection between structures) to polyhydramnios.
Tracheoesophageal fistula (TEF) is a congenital abnormal connection between the trachea and oesophagus, often associated with oesophageal atresia.
In normal fetal development, the fetus swallows amniotic fluid, which is absorbed in the gastrointestinal tract. In TEF with oesophageal atresia, the fetus cannot properly swallow and pass amniotic fluid into the stomach and intestines.
As a result, amniotic fluid accumulates in the amniotic sac, leading to polyhydramnios. This condition is often detected prenatally and may be associated with feeding difficulties, aspiration, and respiratory distress after birth.
Explain the pathophysiology of emphysema
Chronic smoking or α₁-antitrypsin deficiency causes recruitment of inflammatory cells such as neutrophils and macrophages into the alveoli. These cells release proteases including elastase which overwhelm antiprotease protection leading to destruction of elastin and alveolar walls. Loss of alveolar septa decreases surface area for gas exchange and impairs oxygen transfer. Destruction of elastic fibres causes loss of elastic recoil so small airways collapse during expiration leading to air trapping and hyperinflation. Patients therefore have increased work of breathing and develop progressive dyspnoea and hypoxaemia
Explain airway hyperresponsiveness and airway remodelling in asthma
Chronic inflammation damages the airway epithelium exposing sensory nerves and increasing airway sensitivity to triggers such as cold air, exercise and smoke. Cytokines and leukotrienes increase smooth muscle responsiveness causing exaggerated bronchoconstriction. Persistent inflammation also leads to airway remodelling including smooth muscle hypertrophy, goblet cell hyperplasia, mucus gland enlargement, subepithelial fibrosis and thickening of the basement membrane. These structural changes can lead to less reversible airflow obstruction over time
Explain why LABAs carry a specific safety warning
LABAs must never be used as monotherapy because using them without an ICS increases the risk of asthma - related death. So, if someone uses only a LABA, they feel better temporarily because the airways open, symptoms become “hidden” but inflammation can continue worsening silently.
This can lead to severe sudden asthma attacks, delayed medical help because symptoms seemed controlled causing exacerbations.
Differentiate between Community-Acquired Pneumonia (CAP) and Hospital-Acquired Pneumonia (HAP), including one pathogen associated with them.
CAP is acquired outside hospital / in the community. Common pathogens include Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydia pneumoniae, Legionella spp, Influenza, RSV, SARS-CoV-2
HAP develops ≥48 hours after hospital admission. Common pathogens include Pseudomonas aeruginosa, MRSA, Klebsiella pneumoniae and Escherichia coli