respiratory system

Lung Capacity and Factors Affecting It

1. What factors influence lung capacity?

   • Sex (males generally have larger lung capacity)

   • Athletics (trained individuals have higher lung capacity)

   • Genetics (inherited traits affect lung efficiency)

   • Smoking (reduces lung capacity over time)

   • Lung defects (such as cystic fibrosis, affecting airflow)

   • Secondhand smoke (damages lung tissue and function)

   • Working with harsh chemicals (can lead to chronic respiratory issues)

2. What is tidal volume?

   • The amount of air inhaled and exhaled during normal, quiet breathing (approx. 500 mL).

3. What is inspiratory reserve volume (IRV)?

   • The additional amount of air that can be forcibly inhaled after a normal inhalation.

4. What is expiratory reserve volume (ERV)?

   • The additional amount of air that can be forcibly exhaled after a normal exhalation.

5. What is residual volume (RV)?

   • The air that remains in the lungs after forced exhalation, prevents alveolar collapse (~1200 mL).

6. What is vital capacity (VC)?

   • The total amount of air that can be exchanged, includes TV + IRV + ERV.

Mechanics of Breathing

7. What is ventilation?

   • The movement of air in and out of the lungs.

8. What is respiration?

   • The exchange of gases (O₂ & CO₂) in the body.

9. What are the two types of respiration?

   • External respiration: Gas exchange between lungs and blood.

   • Internal respiration: Gas exchange between blood and tissues.

10. What is inspiration?

    • Active process where diaphragm contracts, expanding the thoracic cavity and lowering pressure to pull air in.

11. What is expiration?

    • Passive process where muscles relax, thoracic cavity shrinks, and air is pushed out due to increased pressure.

12. What are the primary muscles of breathing?

    • Diaphragm (main muscle)

    • External intercostals (assist in inspiration)

13. How does pressure change during breathing?

    • Inspiration: Pressure drops inside lungs, air flows in.

    • Expiration: Pressure increases, air flows out.

Anatomy of the Respiratory System

14. What are the three major parts of the respiratory system?

    • Airway

    • Lungs

    • Muscles of respiration

15. What is the function of the upper respiratory tract?

    • Warms, filters, and moistens incoming air.

16. What is the function of the nasal cavity?

    • Divided by the nasal septum, lined with ciliated mucosa, traps contaminants.

17. What are the three sections of the pharynx?

    • Nasopharynx (uppermost)

    • Oropharynx (middle)

    • Laryngopharynx (lowest)

18. What is the epiglottis?

    • A flexible flap of cartilage that covers the airway when swallowing to prevent choking.

19. What is the larynx?

    • Also called the voice box, contains the vocal cords.

20. What is the trachea?

    • Also called the windpipe, 10-12 cm long, supported by C-shaped cartilage rings.

21. What are the bronchi?

    • The trachea divides into the right and left bronchi, which further branch into smaller bronchioles.

22. What are terminal bronchioles?

    • Smallest airways that lead to respiratory bronchioles and alveoli.

23. What are alveoli?

    • Tiny air sacs where gas exchange occurs, surrounded by capillaries.

24. What are the pleural membranes?

    • Visceral pleura: Covers the lungs.

    • Parietal pleura: Lines the thoracic cavity.

Diseases & Conditions

25. What is asthma?

    • Chronic lung disease causing inflammation and constriction of airways.

26. What is acute bronchitis?

    • Short-term infection of bronchial tubes, often viral, causing a cough.

27. What is chronic bronchitis?

    • Long-term bronchitis lasting 3+ months, often caused by smoking.

28. What is COPD (Chronic Obstructive Pulmonary Disease)?

    • Progressive lung disease causing difficulty breathing, often from smoking.

29. What is emphysema?

    • A condition where alveoli lose elasticity, causing shortness of breath.

30. What is cystic fibrosis?

    • Genetic disorder that causes thick mucus, leading to lung infections.

31. What is pneumonia?

    • Infection causing fluid-filled alveoli, making breathing difficult.

32. What is tuberculosis (TB)?

    • Bacterial lung infection, symptoms include chronic cough, chest pain, coughing up blood.

33. What is lung cancer?

    • Most common cancer death, primarily caused by smoking.

Respiratory Rate & Diagnostic Tests

34. What is respiratory rate?

    • The number of breaths per minute (normal = 12-20 BPM in adults).

35. How do fetal lungs develop?

    • Filled with fluid before birth, fully inflated by 2 weeks post-birth.

36. What is a bronchoscopy?

    • Procedure using a camera to visualize air passages.

37. What is a chest X-ray?

    • Imaging test showing lungs, blood vessels, and chest bones.

38. What is a tuberculin skin test?

    • Determines if someone has been exposed to tuberculosis (TB).

39. What is a sputum culture?

    • A test to identify bacteria or fungi causing infections.

Medications for Respiratory Issues

40. What are antitussives?

    • Cough suppressants, act on the brain's cough center (e.g., Robitussin, Delsym).

41. What are expectorants?

    • Loosen mucus, making it easier to cough up (e.g., Mucinex, Robitussin).

Miscellaneous

42. What is pulmonary ventilation?

    • The process of air moving in and out of the lungs.

43. What are non-respiratory air movements?

    • Sneezing, coughing, laughing, crying, hiccups, yawning.

44. What is respiratory gas transport?

    • The movement of oxygen and carbon dioxide in the bloodstream.

45. How does gas exchange occur?

    • By simple diffusion through the respiratory membrane in alveoli.

46. What is external respiration?

    • The exchange of oxygen and carbon dioxide between the alveoli and the blood.

47. What is internal respiration?

    • The exchange of gases between blood and tissue cells.

48. What is respiratory gas transport?

    • Oxygen is transported via hemoglobin in red blood cells, and CO₂ is transported in blood plasma.

49. What role does the diaphragm play in breathing?

    • Contracts during inspiration, increasing thoracic cavity size.

    • Relaxes during expiration, decreasing cavity size.

50. What happens to lung pressure during inspiration?

    • Intrapulmonary pressure drops, pulling air into the lungs.

51. What happens to lung pressure during expiration?

    • Intrapulmonary pressure increases, forcing air out.

Additional Respiratory System Components

52. What is the role of ciliated mucosa?

    • Traps dust, mold, and contaminants, and cilia move particles toward the throat for swallowing.

53. How is air humidified in the respiratory tract?

    • Mucous membranes in the nasal cavity moisten the air before it reaches the lungs.

54. What is the function of the pleural membranes?

    • Visceral pleura covers the lungs; parietal pleura lines the chest cavity.

    • Reduces friction and helps the lungs expand and contract smoothly.

55. Why does residual volume exist in the lungs?

    • Prevents alveoli from collapsing and allows for continuous gas exchange.

More Respiratory Disorders

56. What are the effects of secondhand smoke on the lungs?

    • Damages lung tissue, increases risk of lung cancer, COPD, and respiratory infections.

57. How do harsh chemicals affect the lungs?

    • Prolonged exposure can lead to chronic bronchitis, lung scarring, and cancer.

58. Why is lung cancer so deadly?

    • Spreads quickly and is often diagnosed in late stages.

59. What are the four events of respiration?

    • Pulmonary ventilation (breathing)

    • External respiration (gas exchange in lungs)

    • Respiratory gas transport (oxygen & CO₂ in blood)

    • Internal respiration (gas exchange at tissues)

60. Why do infants have fluid-filled lungs at birth?

    • Fetal lungs don’t function until birth, and they take about two weeks to fully inflate.