The Respiratory System

1. The Respiratory System

2. Respiratory System Functions • Gas exchange: Oxygen enters blood and carbon dioxide leaves • Regulation of blood pH: Altered by changing blood carbon dioxide levels • Voice production: Movement of air past vocal folds makes sound and speech

3. Respiratory System Functions • Olfaction: Smell occurs when airborne molecules drawn into nasal cavity • Protection: Against microorganisms by preventing entry and removing them • Temperature regulation: Panting in some animals

4. Parts of the Nose • Nose • Only externally visible part of the respiratory system • Job is to begin warming, purifying, and humidifying air

5. Parts of the Nose • External Nares (nostrils) • Where air enters the nose • The openings • Nasal Cavity • Interior of the nose • Has thin-walled blood vessels to begin warming air

6. Parts of the Nose • Nasal Septum • Midline dividing nasal cavity into two

7. Parts of the Nose • Respiratory Mucosa • Sticky mucous • Moistens air and traps bacteria & debris • Ciliated cells move mucous back toward throat

9. Parts of the Nose • Conchae • Mucosa-covered projections • Increase surface area & air turbulence • Provide more opportunity for warming & filtration

10. Parts of the Nose • Hard Palate • Anterior separation of nasal & oral cavity • Supported by bone • Soft Palate • Posterior separation of nasal & oral cavity

11. Cleft Palate • Palate does not fuse together • Can also affect the lip

13. Parts of the Nose • Paranasal Sinuses • Openings in skull bones • Lighten the skull • Resonance chambers for speech • Produce mucus

15. Parts of the Pharynx • Pharynx • Muscular passageway for food & air • “Throat” • About 5 inches long • Broken into 3 parts

16. Parts of the Pharynx • Internal Nares • Opening between nasal cavity and pharynx

17. Parts of the Pharynx • Nasopharynx • Oropharynx • Laryngopharynx • Three divisions of Pharynx • Listed from superior to inferior • After passing through, air enters larynx, food enters esophagus

18. Parts of the Pharynx • Pharyngeal Tonsils: • AKA adenoids • High in the nasopharynx • Trap bacteria/pathogens • Palatine Tonsils • In oropharynx, end of soft palate • When you get your tonsils out, this is what is removed • Trap bacteria/pathogens • Lingual Tonsils • Base of the tongue • Trap bacteria/pathogens

21. FYI: Tonsilitis • Catch too much bacteria; palatine tonsils can’t keep up! EEW.

22. http://video.about.com/coldflu/Tonsillitis.htm

23. Larynx • AKA Voice Box • Routes air and food into proper channels • Inferior to pharynx • Formed by 8 rigid cartilages and a spoon-shaped flap of elastic cartilage (epiglottis) • Thyroid cartilage = Adam’s apple

24. Epiglottis • Cartilage flap of larynx; protector! • When not swallowing: • Epiglottis flapped up • Does not block larynx • When you are swallowing: • Larynx rises • Epiglottis falls • Larynx closed off • This means that food is directed into esophagus

26. FYI: If anything other than air tries to enter the larynx, a cough reflex is triggered to get it out and prevent it from going into the lungs!

30. Vocal Folds • Vocal Folds • Formed from folds in larynx membrane • Vibrate with expelled air • Glottis • Slit-like passageway between vocal folds

33. http://video.about.com/coldflu/Laryngitis.htm • YouTube - Video Stroboscopy of the Vocal Cords • YouTube - Mythbusters - Helium and Sulfur Hexafluoride

34. Trachea • AKA windpipe • Has cartilage rings around it to keep it open during pressure changes • About 4 inches long • Lined with ciliated mucosa to propel mucus (with dust particles & debris) away from the lungs to the throat

35. Primary Bronchi • Two (right & left) • Formed by division of trachea • Enters the lung, and then breaks off into secondary bronchi

36. Mediastinum • Most central area of the thoracic cavity • Includes heart, great blood vessels, bronchi, esophagus, etc. (everything except lungs)

37. Lungs • Site of gas exchange • Soft & Spongy, only weigh about 2 ½ pounds • Each lung divided into lobes • Left: 2 lobes • Right: 3 lobes

38. Parts of Lungs • Apex • Narrow superior portion • By clavicle • Base • Wide inferior portion • Rests on diaphragm • Visceral Pleura • Covers surface of lung • Along with parietal pleura, provides attachment and eliminates friction

39. Bronchial Tree • Bronchioles • All of the branching of respiratory passageways in the lungs • Divisions include • Primary bronchi • Secondary bronchi • Tertiary bronchi • Bronchioli • Terminal bronchioli • (end in alveoli)

43. This image is showing the carina – the point where the primary bronchi break off from each other.

44. Alveoli • “Air Sacs” • Resemble bunches of grapes • Make up bulk of lungs

47. Respiratory Zone • Includes respiratory bronchioles, alveolar ducts, alveolar sacs, and alveoli • Only places where gas exchange occurs

48. Walls of Alveoli • Made of single, thin layer of squamous epithelial cells • Covered with a cobweb of pulmonary capillaries

49. Respiratory Membrane • Made up of alveolar and capillary walls • Has air flowing on one side, blood flowing on the other • Gas exchange occurs through simple diffusion • Oxygen from alveolar air to capillary blood • Carbon dioxide leaving blood to air FUN FACT: total surface of alveoli walls is about 50-70 square meters - about the surface of a tennis court!