Understanding the Respiratory System: Functions and Common Conditions

1. Chapter 25 The Respiratory System

2. The Respiratory System • Divided into the upper respiratory tract and the lower respiratory tract • The upper respiratory tract consists of: • Nose or nasal cavity • Paranasal sinuses • Pharynx and larynx

3. The Respiratory System (cont.) • The lower respiratory tract consists of: • Trachea • Two lungs • Two main bronchi

4. Figure 25.1 The upper respiratory tract.

5. Figure 25.2 The lower respiratory tract.

6. Respiration • Diaphragm—dome-shaped layer of muscle that lies across bottom of chest cavity • Breathing occurs as diaphragm contracts and relaxes • Carbon dioxide pushed out of the lungs during relaxation • Oxygen pulled into the lungs during contraction

7. Figure 25.3 The lungs.

8. Structure of Lungs • About 10 percent solid tissue • Remainder of structure filled with air and blood • The functional structure can be divided into two parts: • Conducting airways (bronchi and bronchioles)—tubes lined by cilia and respiratory mucosa • Cartilage—supports and cushions the bronchi

9. Common Cold • Caused by a viral infection that inflames the membranes in nose and throat • Antibiotics will not cure a cold or any other viral infection • Treatment is considered symptomatic

10. Table 25.1 Comparison of Cold and Flu Symptoms

11. Cough • May be a symptom of a cold, flu, respiratory problems, or nonrespiratory diseases • Most likely begins with an irritation of nerves in the respiratory tract • Nonproductive cough treated with cough suppressant • Productive cough treated with an expectorant

12. Allergies • Caused by the immune system reacting to a substance that does not cause disease • Treatment may be palliative, with antihistamines and antitussives • Treatment may be preventive, with mast cell stabilizers

13. Asthma • Chronic respiratory disease • Characterized by inflammation of airways, tightening of muscles around airways • Treatment is palliative with albuterol and other bronchodilators

14. Emphysema • Chronic destruction of alveoli • External exchange interrupted when alveoli become permanently damaged • Treatment may be palliative, with stimulant inhalers • Treatment may be preventive, with anti-inflammatory corticosteroids

15. Rhinitis • Inflammation of nasal membranes, and/or runny nose • Common component of colds and allergies • Treatment is considered symptomatic

16. Nasal Congestion • Inflamed, stuffy nose • Treatment may be palliative, to promote easier breathing • Indications for use of decongestants are nasal and bronchial congestion

17. Bronchoconstriction • Occurs when the smooth muscles encircling the airways or tubes tighten, causing the airways to spasm • Treatment may be palliative • Treatment may be preventive

18. Chronic Obstructive Pulmonary Disease (COPD) • Umbrella term for emphysema and chronic bronchitis • Characterized by partially blocked bronchi and bronchioles • Causes shortness of breath • Treatment may be palliative, with bronchodilators • Treatment may be preventive, with mast cell stabilizers

19. Table 25.2 Comparison of Cough Formula for Nonproductive versus Productive Coughs

20. Table 25.2 (continued) Comparison of Cough Formula for Nonproductive versus Productive Coughs

21. Table 25.3 Nasal Decongestants

22. Table 25.4 Examples of OTC Antihistamines (H-1 Antagonists) Used for Cold and Allergy Symptoms

23. Table 25.5 Examples of Prescription Antihistamines (H-1 Antagonists) for Allergy

24. Table 25.6 Examples of Prescription Ophthalmic Antihistamines (H-1 Antagonists)

25. Table 25.8 Mast Cell Stabilizers

26. Table 25.9 Beta-Adrenergic Bronchodilators

27. Table 25.9 (continued) Beta-Adrenergic Bronchodilators

28. Table 25.10 Various Treatments for Asthma

29. Table 25.11 Corticosteroids

30. Table 25.11 (continued) Corticosteroids

31. Table 25.12 Mast Cell Stabilizers and Antileukotrienes