Understanding the anatomy of respiratory system is vital for B. Pharm students who must link structure to drug action, delivery, and respiratory pathology. This focused overview highlights key anatomical and histological features — nasal cavity, pharynx, larynx, trachea, bronchi, lung lobes and segments, pleura, alveoli, vascular and lymphatic supply, and neural innervation — with clinical correlations relevant to pharmacotherapy. Emphasis on microscopic details (pseudostratified ciliated epithelium, type I/II pneumocytes), bronchopulmonary segmental anatomy, and cardiopulmonary relations strengthens understanding of inhaled agents, regional drug distribution, and disease mechanisms. These concise, exam-oriented MCQs reinforce core concepts and practical applications. Now let’s test your knowledge with 50 MCQs on this topic.
Q1. Which structure forms the primary site of gas exchange in the respiratory system?
- Trachea
- Bronchi
- Alveoli
- Bronchioles
Correct Answer: Alveoli
Q2. Which epithelial type lines most of the conducting portion of the respiratory tract (nasal cavity to bronchi)?
- Simple squamous epithelium
- Pseudostratified ciliated columnar epithelium
- Stratified squamous epithelium
- Transitional epithelium
Correct Answer: Pseudostratified ciliated columnar epithelium
Q3. Type II pneumocytes are primarily responsible for which function?
- Facilitating gas exchange
- Producing surfactant
- Forming the blood-air barrier
- Phagocytosis of bacteria
Correct Answer: Producing surfactant
Q4. The carina is located at the level of which thoracic vertebra in a typical adult?
- T2–T3
- T4–T5
- T6–T7
- T8–T9
Correct Answer: T4–T5
Q5. Which bronchus is more vertical, wider, and thus more prone to aspirated foreign bodies?
- Left main bronchus
- Right main bronchus
- Lobar bronchi
- Segmental bronchi
Correct Answer: Right main bronchus
Q6. The functional units supplied by tertiary (segmental) bronchi are called:
- Lobules
- Alveoli
- Bronchopulmonary segments
- Pulmonary acini
Correct Answer: Bronchopulmonary segments
Q7. Which nerve provides parasympathetic innervation to the bronchial tree, causing bronchoconstriction?
- Phrenic nerve
- Vagus nerve
- Sympathetic chain
- Intercostal nerves
Correct Answer: Vagus nerve
Q8. Pulmonary arteries carry what type of blood to the lungs?
- Oxygenated blood from the left ventricle
- Deoxygenated blood from the right ventricle
- Oxygenated blood from bronchial circulation
- Mixed venous blood from systemic veins
Correct Answer: Deoxygenated blood from the right ventricle
Q9. The visceral pleura is derived embryologically from which layer?
- Somatic mesoderm
- Splanchnic (visceral) mesoderm
- Neural crest
Correct Answer: Splanchnic (visceral) mesoderm
Q10. Which fissure separates the superior and inferior lobes of the left lung?
- Horizontal fissure
- Oblique fissure
- Accessory fissure
- Cardiac fissure
Correct Answer: Oblique fissure
Q11. Bronchial arteries primarily supply which structures?
- Alveolar capillaries
- Conducting airways and supporting tissues of the lung
- Pulmonary veins
- Visceral pleura only
Correct Answer: Conducting airways and supporting tissues of the lung
Q12. Which cell type acts as alveolar macrophages and clears particulates?
- Pneumocyte type I
- Pneumocyte type II
- Dust cells (alveolar macrophages)
- Fibroblasts
Correct Answer: Dust cells (alveolar macrophages)
Q13. The respiratory diverticulum (lung bud) arises from which embryonic structure?
- Foregut endoderm
- Midgut endoderm
- Lateral plate mesoderm
Correct Answer: Foregut endoderm
Q14. The thick, fibrous layer covering the lung surface is called:
- Parietal pleura
- Visceral pleura
- Pulmonary capsule
- Mediastinum
Correct Answer: Visceral pleura
Q15. The conducting zone ends and the respiratory zone begins at which airway structure?
- Terminal bronchiole
- Respiratory bronchiole
- Segmental bronchus
- Trachea
Correct Answer: Respiratory bronchiole
Q16. The mucociliary escalator primarily depends on which cell type lining the airways?
- Goblet cells and ciliated epithelial cells
- Type I pneumocytes
- Clara (Club) cells only
- Squamous epithelial cells
Correct Answer: Goblet cells and ciliated epithelial cells
Q17. Which ligament extends inferiorly from the lung hilum and helps stabilize the lower lobe?
- Pulmonary ligament
- Suspensory ligament
- Triangular ligament
- Phrenic ligament
Correct Answer: Pulmonary ligament
Q18. The left lung has how many lobes and why is it different from the right?
- Two lobes due to the cardiac notch
- Three lobes due to larger size
- Two lobes due to accessory fissure
- One lobe fused by pleural adhesions
Correct Answer: Two lobes due to the cardiac notch
Q19. Which structure is NOT typically found in the lung hilum?
- Bronchus
- Pulmonary artery
- Pulmonary vein
- Thoracic duct
Correct Answer: Thoracic duct
Q20. Which feature best describes the blood–air barrier?
- Thick connective tissue layer for support
- Extremely thin barrier of alveolar epithelium, fused basement membranes, and capillary endothelium
- Multiple epithelial layers to prevent leakage
- Dense fibroelastic tissue to resist pressure
Correct Answer: Extremely thin barrier of alveolar epithelium, fused basement membranes, and capillary endothelium
Q21. Which bronchopulmonary segment is typically targeted for segmental resection in the right upper lobe?
- Superior segment
- Apical, posterior, or anterior segments
- Basal segments
- Lingular segment
Correct Answer: Apical, posterior, or anterior segments
Q22. The pleural cavity normally contains which of the following?
- Large volume of blood
- Air under positive pressure
- Small amount of lubricating serous fluid
- Fatty tissue
Correct Answer: Small amount of lubricating serous fluid
Q23. Which cartilage forms the majority of the anterior wall of the larynx (Adam’s apple)?
- Cricothyroid cartilage
- Thyroid cartilage
- Arytenoid cartilage
- Epiglottic cartilage
Correct Answer: Thyroid cartilage
Q24. The cricoid cartilage is unique because it is:
- Paired and leaf-shaped
- A complete cartilaginous ring
- Made entirely of elastic cartilage
- Absent in adults
Correct Answer: A complete cartilaginous ring
Q25. The level of the tracheal bifurcation (carina) is clinically important during endotracheal intubation because:
- Intubation below the carina risks entering the esophagus
- Placement below the carina will preferentially ventilate one lung
- The carina contains vocal cords
- The carina prevents aspiration
Correct Answer: Placement below the carina will preferentially ventilate one lung
Q26. Which structure separates the nasopharynx from the oropharynx?
- Uvula and soft palate
- Epiglottis
- Tongue base
- Hard palate
Correct Answer: Uvula and soft palate
Q27. Which artery accompanies the bronchial tree and supplies nutrition to bronchi and connective tissue?
- Pulmonary artery
- Bronchial artery
- Superior thoracic artery
- Intercostal artery
Correct Answer: Bronchial artery
Q28. The right middle lobe is separated from the right upper lobe by which fissure?
- Oblique fissure
- Horizontal fissure
- Accessory fissure
- Minor fissure
Correct Answer: Horizontal fissure
Q29. Clara (Club) cells in small bronchioles serve primarily to:
- Produce surfactant for alveoli
- Detoxify inhaled substances and secrete components of surfactant
- Form the basal lamina
- Act as alveolar macrophages
Correct Answer: Detoxify inhaled substances and secrete components of surfactant
Q30. Lymphatic drainage from the lung most commonly flows toward which group of lymph nodes?
- Cervical lymph nodes
- Mediastinal (tracheobronchial) lymph nodes
- Axillary lymph nodes
- Inguinal lymph nodes
Correct Answer: Mediastinal (tracheobronchial) lymph nodes
Q31. Which structure forms the posterior boundary of the superior mediastinum and is closely related to the trachea?
- Esophagus
- Thymus
- Aorta
- Left lung apex
Correct Answer: Esophagus
Q32. Emphysema primarily affects which anatomical component?
- Bronchial cartilage
- Terminal bronchioles
- Alveolar walls (leading to loss of septa and enlarged air spaces)
- Pleural membranes
Correct Answer: Alveolar walls (leading to loss of septa and enlarged air spaces)
Q33. The diaphragm is primarily innervated by which nerve that also impacts respiratory mechanics?
- Vagus nerve
- Phrenic nerve
- Intercostal nerves only
- Accessory nerve
Correct Answer: Phrenic nerve
Q34. In the context of pulmonary anatomy, dead space refers to:
- Alveoli participating in gas exchange
- Air in conducting airways not involved in gas exchange
- Fluid collection in pleural cavity
- Space occupied by pulmonary vessels
Correct Answer: Air in conducting airways not involved in gas exchange
Q35. The posterior cricoarytenoid muscles are functionally important because they:
- Adduct the vocal cords for phonation
- Abduct the vocal cords to open the rima glottidis
- Elevate the larynx during swallowing
- Compress the epiglottis
Correct Answer: Abduct the vocal cords to open the rima glottidis
Q36. Which embryological defect results in a tracheoesophageal fistula most commonly?
- Incomplete separation of the trachea and esophagus from the foregut
- Failure of lung bud branching
- Abnormal pleural cavity formation
- Defective diaphragmatic fusion
Correct Answer: Incomplete separation of the trachea and esophagus from the foregut
Q37. The pulmonary ligament is formed by the reflection of which two pleural layers?
- Parietal and mediastinal pleura
- Visceral and parietal pleura at the hilum
- Visceral pleura and pericardium
- Costal and diaphragmatic pleura
Correct Answer: Visceral and parietal pleura at the hilum
Q38. Which structure forms the ridge at the separation of the oral cavity and oropharynx?
- Soft palate and uvula
- Hard palate
- Epiglottis
- Tongue frenulum
Correct Answer: Soft palate and uvula
Q39. Which statement about pulmonary veins is true?
- They follow bronchi deep into the lung parenchyma
- They carry deoxygenated blood to the heart
- They drain oxygenated blood from the lungs to the left atrium
- They supply nutrients to bronchial tissue
Correct Answer: They drain oxygenated blood from the lungs to the left atrium
Q40. The apex of the lung projects superiorly into which region?
- Epigastric region
- Root of the neck (supraclavicular area)
- Inguinal region
- Axilla only
Correct Answer: Root of the neck (supraclavicular area)
Q41. Which histological change is characteristic of chronic bronchitis?
- Atrophy of mucous glands
- Hypertrophy and hyperplasia of mucous glands with increased goblet cells
- Destruction of alveolar septa
- Loss of ciliated epithelium replaced by cartilage
Correct Answer: Hypertrophy and hyperplasia of mucous glands with increased goblet cells
Q42. The sensory limb for the cough reflex in the larynx is primarily via which nerve?
- Accessory nerve
- Internal branch of superior laryngeal nerve (branch of vagus)
- Phrenic nerve
- Hypoglossal nerve
Correct Answer: Internal branch of superior laryngeal nerve (branch of vagus)
Q43. The major difference between terminal bronchioles and respiratory bronchioles is:
- Terminal bronchioles contain alveoli while respiratory bronchioles do not
- Respiratory bronchioles have alveolar outpouchings and participate in gas exchange
- Terminal bronchioles have cartilage plates
- Respiratory bronchioles possess pseudostratified epithelium only
Correct Answer: Respiratory bronchioles have alveolar outpouchings and participate in gas exchange
Q44. The cardiac notch is a feature of which lung and has what clinical implication?
- Right lung; allows cardiac auscultation over right anterior chest
- Left lung; provides space for the heart and influences surgical approach
- Right lung; reduces lung volume for inhalation
- Left lung; causes frequent fissure abnormalities
Correct Answer: Left lung; provides space for the heart and influences surgical approach
Q45. Which cell junction is particularly important in maintaining the thinness of alveolar epithelium for gas exchange?
- Gap junctions between endothelial cells
- Tight junctions limiting paracellular leak
- Desmosomes providing tensile strength
- Hemidesmosomes anchoring epithelium to cartilage
Correct Answer: Tight junctions limiting paracellular leak
Q46. Which anatomical relation is most posterior to the trachea in the superior mediastinum?
- Ascending aorta
- Esophagus
- Thymus
- Right brachiocephalic vein
Correct Answer: Esophagus
Q47. In normal lung anatomy, which statement about bronchopulmonary segments is correct?
- They are surgically indivisible functional units
- Each is supplied by its own tertiary bronchus and a branch of the pulmonary artery
- They are separated by complete connective tissue septa that prevent disease spread
- They correspond directly to lobules
Correct Answer: Each is supplied by its own tertiary bronchus and a branch of the pulmonary artery
Q48. Which structure predominates at the hilum of the lung and is typically located most superiorly on the right side?
- Pulmonary veins
- Pulmonary artery
- Main bronchus
- Bronchial veins
Correct Answer: Main bronchus
Q49. Surfactant reduces surface tension in alveoli primarily by:
- Increasing water content of alveoli
- Interrupting hydrogen bonds between water molecules at the air–liquid interface
- Thickening the alveolar wall
- Stimulating type I pneumocyte proliferation
Correct Answer: Interrupting hydrogen bonds between water molecules at the air–liquid interface
Q50. A spontaneous pneumothorax most directly results from which anatomical event?
- Accumulation of pleural fluid due to heart failure
- Air entering the pleural space leading to lung collapse
- Blood accumulation in the pleural cavity compressing the lung
- Fibrosis of visceral pleura causing restrictive lung disease
Correct Answer: Air entering the pleural space leading to lung collapse
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
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