The respiratory system supplies the body with oxygen and removes carbon dioxide through four processes: pulmonary ventilation, external respiration, transport of respiratory gases, and internal respiration. The main organs involved are the nose, pharynx, larynx, trachea, bronchi, lungs, and alveoli. The nose warms and filters air while the lungs and alveoli facilitate gas exchange between the air and blood. Various disorders can affect the respiratory system such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis.

1. The Respiratory
System

2. The Respiratory System
• Supplies body with oxygen
• Disposes of carbon dioxide
• Four processes in respiration
• Pulmonary ventilation
• External respiration
• Transport of respiratory gases
• Internal respiration

3. Functional Anatomy of the Respiratory System
• Respiratory organs
• Nose, nasal cavity, and paranasal sinuses
• Pharynx, larynx, and trachea
• Bronchi and smaller branches
• Lungs and alveoli
• Divided into:
• Conducting zone
• Respiratory zone

4. Organs of the Respiratory System

5. The Nose
• Provides an airway for
respiration
• Moistens and warms air
• Filters inhaled air
• Resonating chamber for
speech
• Houses olfactory receptors

6. Basic Anatomy of the Upper Respiratory Tract

7. The Nasal Cavity
• Two types of mucosa
• Olfactory mucosa – houses olfactory receptors
• Respiratory mucosa – lines nasal cavity
• Consists of:
• Pseudostratified ciliated columnar epithelium
• Goblet cells within epithelium
• Underlying layer of lamina propria
• Cilia move contaminated mucus posteriorly

8. Nasal Conchae
• Superior and middle – part of the ethmoid bone
• Inferior – a separate bone
• Project medially from the lateral wall of the nasal
cavity
• Particulate matter – deflected to mucus-coated
surfaces

9. The Paranasal Sinuses

10. The Larynx
• Three functions
• Voice production
• Provides an open airway
• Routes air and food into the proper channels

11. Anatomy of the Larynx

12. Movements of the Vocal Folds

13. The Larynx
• Voice production
• Length of the vocal folds changes with pitch
• Loudness depends on the force of air across the
vocal folds
• Sphincter function of the larynx
• Valsalva’s maneuver

14. The Trachea
• Descends into the mediastinum
• Divides into two main bronchi
• C-shaped cartilage rings keep airway open

15. Bronchi in the Conducting Zone
• Bronchial tree – extensively branching respiratory
passageways
• Primary bronchi (main bronchi) – largest bronchi
• Right main bronchi – wider and shorter than the
left

16. Bronchi in the Conducting Zone

17. Bronchi in the Conducting Zone
• Secondary (lobar) bronchi
• Three on the right
• Two on the left
• Tertiary (segmental) bronchi
• Branch into each lung segment
• Bronchioles – little bronchi, less than 1 mm in
diameter
• Terminal bronchioles – less than 0.5 mm in
diameter

18. Changes in Tissue Composition along Conducting Pathways
• Supportive connective tissues change
• C-shaped rings replaced by cartilage plates
• Epithelium changes
• First, pseudostratified ciliated columnar
• Replaced by simple columnar, then simple
cuboidal epithelium
• Smooth muscle becomes important

19. The Respiratory Zone
• Consists of air-exchanging structures
• Respiratory bronchioles – branch from terminal
bronchioles
• Lead to alveolar ducts
• Lead to alveolar sacs

20. The Respiratory Zone
• Alveoli consist of type
I cells and basal
laminae
• Scattered among type
I cells
• Cuboidal epithelial
cells – type II cells
• Secrete surfactant

21. Anatomy of Alveoli and the Respiratory Membrane

22. Diagram of the Pleurae and Pleural Cavities

23. Transverse Cut through the Superior Thorax

24. The Mechanisms of Ventilation
• Two phases of pulmonary ventilation
• Inspiration – inhalation
• Expiration – exhalation

25. Changes in Thoracic Volume

26. Changes in Thoracic Volume

27. Neural Control of Ventilation
• Respiratory center – generates baseline respiration
rate
• In the reticular formation of the medulla oblongata
• Chemoreceptors – sensitive to rising and falling
oxygen levels
• Central chemoreceptors – located in medulla
• Peripheral chemoreceptors
• Aortic bodies
• Carotid bodies

28. Location of Peripheral Chemoreceptors

29. Disorders of Lower Respiratory Structures
• Bronchial asthma – a type of allergic inflammation
• A hypersensitivity to irritants in the air or to stress
• Asthma attacks characterized by:
• Contraction of bronchiole smooth muscle
• Secretion of mucus in airways

30. Disorders of Lower Respiratory Structures
• Chronic obstructive pulmonary disease (COPD)
• Airflow into and out of the lungs is difficult
• Obstructive emphysema
• Chronic bronchitis
• History of smoking

31. Disorders of Lower Respiratory Structures
• Cystic fibrosis (CF) – inherited disease
• Exocrine gland function is disrupted
• Respiratory system affected by:
• Oversecretion of viscous mucus

32. Disorders of Upper Respiratory Structures
• Epistaxis – nosebleed
• Epiglottitis – inflammation and swelling of the
epiglottis