Enhance your knowledge with our comprehensive guide and curated study materials.
1. What are the main functions of the lungs?
→ The lungs are the primary organs of respiration, responsible for exchange of oxygen and carbon dioxide, regulation of acid-base balance, and participation in filtering blood and metabolic activities (like conversion of angiotensin I to II).
2. Why is the right lung larger than the left?
→ The right lung is larger, shorter, and wider because the liver lies below it, elevating the diaphragm. The left lung is smaller due to the presence of the heart on that side.
3. How many lobes are present in each lung?
→
Right lung: 3 lobes — upper, middle, and lower.
Left lung: 2 lobes — upper and lower, with a lingula representing the middle lobe.
4. What are the fissures of the lungs?
→
Right lung: Oblique and horizontal fissures.
Left lung: Only oblique fissure.
5. What is the cardiac notch?
→ A deep indentation on the anterior border of the left lung below the 4th costal cartilage to accommodate the heart.
6. What is the lingula?
→ A tongue-like projection from the upper lobe of the left lung, equivalent to the middle lobe of the right lung.
7. What is the root of the lung?
→ The collection of structures connecting the lung to the mediastinum, including bronchi, pulmonary vessels, bronchial vessels, nerves, and lymphatics.
8. What is the arrangement of structures in the root of the lung?
→
Right lung: Bronchus – Artery – Bronchus – Veins (B-A-B-V).
Left lung: Artery – Bronchus – Veins (A-B-V).
9. What are the contents of the root of the lung?
→
Principal bronchus (right: eparterial and hyparterial)
Pulmonary artery and veins
Bronchial arteries and veins
Lymph nodes and lymph vessels
Pulmonary nerve plexuses (anterior and posterior)
10. What is the hilum of the lung?
→ A triangular depression on the mediastinal surface of each lung where structures of the root enter and leave.
11. What are the surfaces of the lung?
→
Costal surface: convex, related to ribs.
Mediastinal surface: concave, related to heart and great vessels.
Diaphragmatic surface: concave, rests on diaphragm.
12. What are the borders of the lung?
→
Anterior border: sharp and thin.
Posterior border: rounded, corresponds to vertebral column.
Inferior border: separates base from costal and medial surfaces.
13. What is the carina?
→ A cartilaginous ridge at the tracheal bifurcation (T4 level) marking the division into right and left bronchi.
It is highly sensitive, and stimulation causes violent cough.
14. Why are foreign bodies more often found in the right lung?
→ The right bronchus is shorter, wider, and more vertical, making it a direct continuation of the trachea.
15. What are bronchopulmonary segments?
→ Pyramidal subdivisions of lung tissue, each supplied by its own segmental bronchus and artery, and separated by connective tissue septa.
16. How many bronchopulmonary segments are there?
→ Ten in each lung, though some may fuse in the left lung.
17. What is the surgical importance of bronchopulmonary segments?
→ Each segment is functionally and surgically independent, allowing segmental resection in disease without affecting other segments.
18. What is the blood supply of the lungs?
→
Pulmonary circulation: Pulmonary arteries (deoxygenated blood) and pulmonary veins (oxygenated blood).
Bronchial circulation: Bronchial arteries (nutrient supply) and veins.
19. What is the nerve supply of the lungs?
→
Parasympathetic (Vagus): Bronchoconstriction, vasodilation, secretion.
Sympathetic (T1–T5): Bronchodilation, vasoconstriction, decreased secretion.
20. What are the stages of lung development?
→ Pseudoglandular, Canalicular, Terminal sac, Alveolar.
21. What is the embryological origin of the lung epithelium?
→ Endoderm of the foregut.
22. What is the molecular regulation of lung development?
→
TBX4 — induces lung bud formation.
FGF10 — promotes bronchial outgrowth.
SHH (Sonic Hedgehog) — regulates branching pattern.
23. When does surfactant appear in fetal life?
→ Around 28–32 weeks of gestation, produced by Type II pneumocytes.
24. What is the function of surfactant?
→ Reduces surface tension and prevents alveolar collapse at the end of expiration.
25. What happens in surfactant deficiency?
→ Leads to Neonatal Respiratory Distress Syndrome (Hyaline Membrane Disease) in premature infants.
26. What is the histological feature of a bronchus?
→ Pseudostratified ciliated columnar epithelium, cartilage plates, and mucous glands.
27. What is the histological feature of a bronchiole?
→ Simple columnar to cuboidal epithelium, no cartilage, and no glands.
28. What are the types of alveolar cells?
→
Type I pneumocytes: Thin cells for gas exchange.
Type II pneumocytes: Secrete surfactant.
29. What are the main impressions on the medial surface of the right lung?
→ Superior vena cava, inferior vena cava, azygos vein, right atrium, oesophagus.
30. What are the main impressions on the medial surface of the left lung?
→ Heart (left ventricle), aortic arch, descending aorta, oesophagus.
31. Why is knowledge of fissures important clinically?
→ Helps in locating lung lesions, pleural effusions, and interpreting X-rays; incomplete fissures can cause spread of infection between lobes.
32. What is the clinical significance of carina?
→ Its widening or distortion on bronchoscopy indicates subcarinal lymph node enlargement or carcinoma.
33. What are the common sites of bronchogenic carcinoma?
→ Hilum and upper lobes of the lungs.
34. What is pulmonary embolism?
→ Blockage of a pulmonary artery by a thrombus, usually from deep veins of legs.
35. What is atelectasis?
→ Collapse of alveoli due to airway obstruction or loss of surfactant.
36. What is bronchial asthma?
→ Reversible airway obstruction caused by bronchial smooth muscle constriction and mucus secretion.
37. What is bronchiectasis?
→ Permanent dilation of bronchi due to chronic infection or obstruction, leading to foul-smelling sputum and recurrent infections.
38. What is an azygos lobe?
→ A small accessory lobe of the right lung formed by an aberrant azygos vein arching over the lung apex.
39. Why is the apex of the lung important clinically?
→ It may be affected in tuberculosis and Pancoast tumors, which can invade the brachial plexus and sympathetic chain.
40. What is Pancoast’s syndrome?
→ Caused by apical carcinoma of lung compressing T1 spinal nerve and sympathetic chain, resulting in Horner’s syndrome (ptosis, miosis, anhidrosis).
41. Which condition is caused by inhalation of dust particles?
→ Pneumoconiosis — e.g., silicosis, asbestosis, coal worker’s disease.
42. What is emphysema?
→ Destruction of alveolar walls and loss of elasticity, causing overinflation of lungs and air trapping.
43. What is the sentinel (Virchow’s) node and its importance?
→ Left supraclavicular node — enlargement indicates metastasis from bronchogenic carcinoma or abdominal malignancy.
44. Why is the knowledge of lung segments important in surgery?
→ Enables segmental resection of diseased areas without impairing function of other parts.
45. What are the common causes of pleural effusion secondary to lung disease?
→ Pneumonia, tuberculosis, carcinoma, or pulmonary embolism.
46. What is postural drainage?
→ A physiotherapy technique using gravity-assisted positioning to drain bronchial secretions from specific lung segments.
47. Which condition involves air in the pleural cavity?
→ Pneumothorax.
48. What causes hoarseness in advanced lung cancer?
→ Compression of the left recurrent laryngeal nerve by mediastinal lymph nodes.
49. What is the clinical significance of bronchial artery anastomosis?
→ Provides collateral circulation in pulmonary artery obstruction and contributes to hemoptysis in chronic lung disease.
50. What imaging technique is most useful for detecting pulmonary embolism?
→ CT pulmonary angiography.
Here are 50 comprehensive MCQs covering the gross anatomy, development, histology, and clinical anatomy of lungs, ideal for MBBS and NEET-PG revision.
1. The lungs develop as an outgrowth from which embryonic structure?
a) Midgut
b) Foregut
c) Hindgut
d) Pharyngeal pouch
Answer: b) Foregut
2. The respiratory diverticulum appears during which week of development?
a) 2nd week
b) 3rd week
c) 4th week
d) 5th week
Answer: c) 4th week
3. The epithelium of alveoli is derived from:
a) Ectoderm
b) Endoderm
c) Mesoderm
d) Neural crest
Answer: b) Endoderm
4. The connective tissue and cartilage of the lungs are derived from:
a) Somatic mesoderm
b) Splanchnic mesoderm
c) Intermediate mesoderm
d) Neural crest
Answer: b) Splanchnic mesoderm
5. The molecular factor essential for lung bud initiation is:
a) FGF10
b) WNT
c) TBX5
d) HOXA13
Answer: a) FGF10
6. The TBX4 gene is responsible for:
a) Alveolar surfactant production
b) Lung bud formation
c) Vascular branching
d) Ciliary differentiation
Answer: b) Lung bud formation
7. The trachea develops from:
a) Dorsal wall of foregut
b) Ventral wall of foregut
c) Midgut
d) Hindgut
Answer: b) Ventral wall of foregut
8. The tracheo-oesophageal septum separates:
a) Pharynx and oesophagus
b) Larynx and trachea
c) Trachea and oesophagus
d) Bronchi and alveoli
Answer: c) Trachea and oesophagus
9. Which stage of lung development is characterized by formation of terminal bronchioles?
a) Canalicular
b) Pseudoglandular
c) Terminal sac
d) Alveolar
Answer: b) Pseudoglandular
10. Surfactant is secreted by:
a) Type I pneumocytes
b) Type II pneumocytes
c) Clara cells
d) Goblet cells
Answer: b) Type II pneumocytes
11. Surfactant production begins around:
a) 20 weeks
b) 28 weeks
c) 36 weeks
d) Birth
Answer: b) 28 weeks
12. Surfactant prevents:
a) Pulmonary embolism
b) Alveolar collapse
c) Lung fibrosis
d) Pulmonary edema
Answer: b) Alveolar collapse
13. Deficiency of surfactant causes:
a) Pneumonia
b) Hyaline membrane disease
c) Bronchial asthma
d) Tuberculosis
Answer: b) Hyaline membrane disease
14. Which is the smallest functional unit of the lung?
a) Alveolus
b) Bronchus
c) Bronchopulmonary segment
d) Pulmonary lobule
Answer: a) Alveolus
15. The right lung has how many lobes?
a) One
b) Two
c) Three
d) Four
Answer: c) Three
16. The left lung has how many fissures?
a) One
b) Two
c) Three
d) Four
Answer: a) One
17. The horizontal fissure of the right lung corresponds to which rib anteriorly?
a) 3rd
b) 4th
c) 5th
d) 6th
Answer: b) 4th
18. The oblique fissure begins at the level of which thoracic vertebra?
a) T2
b) T3
c) T4
d) T5
Answer: c) T4
19. The cardiac notch is present in:
a) Right lung
b) Left lung
c) Both lungs
d) None
Answer: b) Left lung
20. The lingula belongs to which lobe?
a) Right middle lobe
b) Left upper lobe
c) Right lower lobe
d) Left lower lobe
Answer: b) Left upper lobe
21. The right bronchus is:
a) Longer and narrower
b) Shorter and wider
c) Longer and more oblique
d) Same as left
Answer: b) Shorter and wider
22. Foreign bodies most often enter:
a) Left main bronchus
b) Right main bronchus
c) Trachea
d) Larynx
Answer: b) Right main bronchus
23. The ridge at the bifurcation of trachea is known as:
a) Carina
b) Lingula
c) Cardiac notch
d) Crista
Answer: a) Carina
24. The carina is situated at the level of:
a) T2
b) T3
c) T4
d) T6
Answer: c) T4
25. Each lung has how many bronchopulmonary segments?
a) 6
b) 8
c) 10
d) 12
Answer: c) 10
26. The bronchopulmonary segments are separated by:
a) Pleura
b) Intersegmental septa
c) Alveolar septa
d) Bronchial walls
Answer: b) Intersegmental septa
27. Which of the following bronchi divides before entering the lung?
a) Left principal bronchus
b) Right principal bronchus
c) Segmental bronchus
d) Terminal bronchiole
Answer: b) Right principal bronchus
28. The pulmonary artery in the right lung root lies:
a) Above the bronchus
b) Below the bronchus
c) Between two bronchi
d) Behind the bronchus
Answer: c) Between two bronchi
29. The pulmonary veins in both lungs lie:
a) Above bronchi
b) Anterior and inferior to bronchi
c) Posterior to bronchi
d) Between bronchi and arteries
Answer: b) Anterior and inferior to bronchi
30. The bronchial arteries supply:
a) Alveoli
b) Bronchial walls
c) Pleura
d) Heart
Answer: b) Bronchial walls
31. The lymph from the lungs drains first into:
a) Tracheobronchial nodes
b) Bronchopulmonary (hilar) nodes
c) Paratracheal nodes
d) Deep cervical nodes
Answer: b) Bronchopulmonary (hilar) nodes
32. Nerve supply to the lungs is via:
a) Phrenic nerve
b) Vagus and sympathetic nerves
c) Intercostal nerves
d) Recurrent laryngeal nerve
Answer: b) Vagus and sympathetic nerves
33. Parasympathetic stimulation of lungs causes:
a) Bronchodilation
b) Bronchoconstriction
c) Vasoconstriction
d) Dryness of airway
Answer: b) Bronchoconstriction
34. Sympathetic stimulation causes:
a) Bronchoconstriction
b) Bronchodilation
c) Secretion increase
d) Vasodilation
Answer: b) Bronchodilation
35. The pulmonary veins carry:
a) Oxygenated blood
b) Deoxygenated blood
c) Lymph
d) Mixed blood
Answer: a) Oxygenated blood
36. The pulmonary arteries carry:
a) Oxygenated blood
b) Deoxygenated blood
c) Lymph
d) Mixed blood
Answer: b) Deoxygenated blood
37. The most common site of lung abscess formation is:
a) Apex of lung
b) Posterior segment of upper lobe
c) Anterior basal segment of lower lobe
d) Lingula
Answer: b) Posterior segment of upper lobe
38. In aspiration pneumonia, the most commonly affected area is:
a) Apical lobe
b) Middle lobe
c) Posterior basal segment of lower lobe
d) Anterior segment
Answer: c) Posterior basal segment of lower lobe
39. The most common site for primary tuberculosis is:
a) Apex of lung
b) Middle lobe
c) Lower lobe
d) Lingula
Answer: a) Apex of lung
40. Pancoast’s tumor affects which structure?
a) Carina
b) Brachial plexus and sympathetic chain
c) Phrenic nerve
d) Vagus nerve
Answer: b) Brachial plexus and sympathetic chain
41. The hallmark of emphysema is:
a) Fibrosis
b) Loss of alveolar elasticity
c) Collapse of lung
d) Pleural effusion
Answer: b) Loss of alveolar elasticity
42. Hoarseness of voice in lung cancer is due to:
a) Phrenic nerve injury
b) Compression of left recurrent laryngeal nerve
c) Vagus nerve irritation
d) Right recurrent laryngeal nerve compression
Answer: b) Compression of left recurrent laryngeal nerve
43. The apex of the lung extends above the clavicle by:
a) 1 cm
b) 2.5 cm
c) 3 cm
d) 5 cm
Answer: b) 2.5 cm
44. The root of the lung lies opposite which vertebrae?
a) T2–T4
b) T4–T5
c) T5–T7
d) T7–T9
Answer: c) T5–T7
45. The azygos lobe is a feature of:
a) Left lung
b) Right lung
c) Both lungs
d) Fetal lungs only
Answer: b) Right lung
46. The costodiaphragmatic recess is deepest in:
a) Midclavicular line
b) Midaxillary line
c) Scapular line
d) Vertebral line
Answer: b) Midaxillary line
47. The most common cause of pulmonary embolism is:
a) Fat embolism
b) Thrombus from deep veins of legs
c) Amniotic embolism
d) Air embolism
Answer: b) Thrombus from deep veins of legs
48. Which cell type lines most of the alveolar surface?
a) Type I pneumocytes
b) Type II pneumocytes
c) Clara cells
d) Goblet cells
Answer: a) Type I pneumocytes
49. The main histological difference between bronchi and bronchioles is:
a) Presence of glands in bronchioles
b) Absence of cartilage and glands in bronchioles
c) Ciliated epithelium absent in bronchioles
d) Goblet cells absent in bronchioles
Answer: b) Absence of cartilage and glands in bronchioles
50. In chest X-ray, the horizontal fissure of the right lung corresponds to which rib level?
a) 3rd rib
b) 4th rib
c) 5th rib
d) 6th rib
Answer: b) 4th rib
Q1. What are the main functions of the lungs?
→ Exchange of gases (O₂ uptake and CO₂ elimination), regulation of blood pH, phonation assistance, and metabolic functions such as activation of angiotensin I to II.
Q2. What is the position and shape of each lung?
→ Each lung is conical, with an apex projecting into the neck above the clavicle and a concave base resting on the diaphragm. The right lung is larger, shorter, and wider; the left lung is smaller and narrower due to the heart.
Q3. Why is the right lung larger than the left?
→ The liver elevates the right diaphragm making the lung shorter but broader; the heart occupies more space on the left, reducing lung size there.
Q4. How many lobes and fissures are in each lung?
→
Right lung: 3 lobes (upper, middle, lower) with 2 fissures (oblique + horizontal).
Left lung: 2 lobes (upper, lower) with 1 fissure (oblique only).
Q5. What is the cardiac notch and lingula?
→ The cardiac notch is an indentation on the anterior border of the left lung for the heart.
The lingula is a tongue-like projection of the left upper lobe, equivalent to the middle lobe of the right lung.
Q6. Name the borders of each lung.
→ Anterior (thin), posterior (thick, rounded), and inferior (sharp) borders.
Q7. What are the surfaces of the lungs?
→ Costal surface (convex, facing ribs), medial/mediastinal surface (concave, facing heart and mediastinum), and diaphragmatic surface (concave, resting on diaphragm).
Q8. What structures form the root of the lung?
→ Principal bronchus (two in right, one in left), pulmonary artery, two pulmonary veins, bronchial vessels, lymphatics, and pulmonary plexuses bound by pleura.
Q9. How are the structures arranged in the root of each lung?
→ Right lung: Bronchus–Artery–Bronchus–Veins (B-A-B-V)
Left lung: Artery–Bronchus–Veins (A-B-V)
Q10. What is the hilum of the lung?
→ The medial surface depression where structures of the root enter and leave.
Q11. What is the difference between right and left principal bronchi?
→ Right is shorter (2.5 cm), wider, and more vertical (25°); left is longer (5 cm), narrower, and more oblique (45°)—hence foreign bodies commonly lodge in the right.
Q12. What is the carina?
→ A cartilaginous ridge at the tracheal bifurcation (T4 level) that is extremely sensitive, triggering the cough reflex when stimulated.
Q13. What are bronchopulmonary segments?
→ Pyramidal subdivisions of lung tissue, each supplied by a segmental bronchus and artery, drained by intersegmental veins, and separated by connective-tissue septa—functionally independent.
Q14. How many bronchopulmonary segments exist in each lung?
→ Usually ten in each lung, though some fuse in the left lung.
Q15. What is the surgical importance of these segments?
→ Allows segmental resection in localized disease without compromising other segments.
Q16. What is the blood supply of the lungs?
→
Pulmonary arteries — deoxygenated blood for gas exchange.
Pulmonary veins — oxygenated blood to left atrium.
Bronchial arteries — nutritional supply to bronchial walls.
Q17. What is the nerve supply of the lungs?
→ Parasympathetic (vagus): bronchoconstriction, vasodilation, secretion.
Sympathetic (T1–T5): bronchodilation, vasoconstriction, reduced secretion.
Q18. What is the lymphatic drainage of the lungs?
→ Superficial (subpleural) and deep plexuses drain into bronchopulmonary → tracheobronchial → paratracheal → deep cervical nodes → thoracic or right lymphatic duct.
Q19. Which part of the lung is most affected by tuberculosis?
→ Apex, owing to its high oxygen tension.
Q20. What are the common impressions on the right lung?
→ SVC, IVC, right atrium, azygos vein, and oesophagus.
Q21. What are the impressions on the left lung?
→ Heart (left ventricle), arch and descending aorta, oesophagus, and thoracic duct.
Q22. What are the four stages of lung development?
→ Pseudoglandular (5–17 wks), Canalicular (16–25 wks), Terminal sac (24 wks–birth), Alveolar (birth–8 yrs).
Q23. From which germ layers are the lungs derived?
→ Endoderm (epithelium) and splanchnic mesoderm (muscle, cartilage, connective tissue).
Q24. When does surfactant appear?
→ Around 28–32 weeks of gestation.
Q25. What is the function of surfactant?
→ Reduces surface tension in alveoli, preventing their collapse during expiration.
Q26. Which cells secrete surfactant?
→ Type II pneumocytes.
Q27. What is the main histological difference between bronchus and bronchiole?
→ Bronchi possess cartilage plates and glands; bronchioles lack both.
Q28. Name the two types of alveolar cells and their functions.
→ Type I: gas exchange; Type II: surfactant secretion.
Q29. What is the respiratory membrane?
→ A thin barrier between alveolar air and blood: alveolar epithelium + fused basement membranes + capillary endothelium.
Q30. What is the significance of negative intrapleural pressure?
→ Keeps lungs inflated against the chest wall, preventing collapse.
Q31. Why are foreign bodies more often found in the right lower lobe?
→ Because the right bronchus is vertical and wider; gravity directs objects into posterior basal segment.
Q32. What is bronchogenic carcinoma?
→ Malignant tumor arising from bronchial epithelium, strongly linked to smoking; commonly located near the hilum.
Q33. How does bronchogenic carcinoma cause hoarseness of voice?
→ By compressing the left recurrent laryngeal nerve as it loops under the aortic arch.
Q34. What is bronchiectasis?
→ Irreversible dilation of bronchi due to chronic infection and wall destruction, usually in lower lobes.
Q35. What is pulmonary embolism?
→ Blockage of a pulmonary artery by a thrombus from the deep veins of the legs.
Q36. What is pneumothorax?
→ Air in the pleural cavity causing lung collapse; may be spontaneous, traumatic, or tension type.
Q37. What is atelectasis?
→ Collapse of alveoli due to airway obstruction or surfactant deficiency.
Q38. What is emphysema?
→ Permanent enlargement of air spaces with destruction of alveolar walls, leading to air trapping and poor gas exchange.
Q39. What is Pancoast’s tumor?
→ Apical carcinoma of lung invading brachial plexus (T1) and sympathetic chain, producing shoulder pain and Horner’s syndrome.
Q40. What is Horner’s syndrome?
→ Triad of ptosis, miosis, and anhidrosis from sympathetic interruption, often due to apical lung tumor.
Q41. What is pulmonary infarction?
→ Wedge-shaped necrosis of lung tissue following pulmonary embolism; apex toward hilum, base toward pleura.
Q42. What is an azygos lobe?
→ An accessory lobe of the right lung formed when the azygos vein arches over the apex, creating an extra fissure—radiologically benign variant.
Q43. What is neonatal respiratory distress syndrome (NRDS)?
→ Seen in premature infants from surfactant deficiency, causing alveolar collapse and formation of hyaline membranes.
Q44. What is pleural effusion secondary to lung disease?
→ Accumulation of fluid in pleural cavity due to pneumonia, carcinoma, or heart failure; obliterates costodiaphragmatic recess.
Q45. What is postural drainage?
→ A physiotherapy technique that uses gravity to drain mucus from specific bronchopulmonary segments.
Q46. What is the sentinel (Virchow’s) node and its importance?
→ Left supraclavicular lymph node—its enlargement indicates metastasis from thoracic or abdominal malignancy, especially lung cancer.
Q47. What are the histological layers of an intrapulmonary bronchus?
→ Epithelium (pseudostratified ciliated), lamina propria, smooth muscle, submucosa with glands, cartilage plates, adventitia.
Q48. What is the function of Clara cells?
→ Present in terminal bronchioles; detoxify harmful substances and secrete components of surfactant.
Q49. Why does left lung infection occasionally spread to pericardium?
→ The mediastinal pleura and pericardium are closely related on the left side, allowing inflammatory extension.
Q50. Why is understanding lung anatomy important clinically?
→ It guides bronchoscopy, radiological interpretation, thoracic surgery, and emergency procedures such as chest tube insertion.
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