Respiratory System

1. Respiratory System Gas exchange (oxygen & carbon dioxide)

2. Nose/Nasal Cavity • Air is warmed, filtered and moisturized • Smell receptors are located at the top of the nasal cavity • Sinuses are mucus-lined cavities in the skull bones that communicate with the nasal cavity

4. Pharynx • Air then passes to your throat or pharynx which is a common opening for digestion and respiration

5. Larynx • Air then passes into your larynx • You might have called this your “Adam’s apple” or “voice box” • Made of cartilage • Epiglottis is a triangular flap of the larynx that closes the larynx when you swallow food

7. Larynx • Also houses your vocal cords that vibrate as air moves past them

9. Trachea • Windpipe • Supported by cartilaginous rings • Lined with cilia to keep debris out of the lower respiratory structures

12. Bronchi & Bronchioles • The trachea branches into two large branches called bronchi • These bronchi enter the lungs and subsequently branch into smaller and smaller branch, • Until they become the smallest bronchi, termed bronchioles

14. Bronchi • Large bronchi have cartilage in their walls for support • Small bronchioles do not have cartilage in their walls

15. Lungs • The two lungs are elastic sacs filled with the bronchi, bronchioles, and blood vessels. • Lungs also have millions of tiny air sacs called alveoli.

18. Alveoli • Alveoli have a very thin wall • Alveoli are surrounded by numerous blood capillaries • This is the site of gas (oxygen & carbon dioxide) exchange

21. Respiratory Physiology • Ventilation, or breathing, has two components: • Inhalation = Inspiration • Exhalation = Expiration

22. Inhalation • This brings air into the airways and lungs • The diaphragm contracts and the ribcage moves up and out • The chest cavity enlarges, as do the lungs • This lowers the air pressure in the lungs so that air moves from high to low pressure into the lungs

24. Exhalation • Air moves out of the lungs and airways • The diaphragm raises and the ribcage moves in and down • This decreases the size of the chest cavity and the lungs, thus increasing the pressure in the airways • Air naturally moves from an area of high pressure to an area of lower pressure, outside to the atmosphere.

27. Diffusion • Diffusion of oxygen and carbon dioxide occurs between the alveoli and the pulmonary capillaries • Oxygen moves from alveoli to capillaries • Carbon dioxide moves from capillaries to alveoli to be exhaled

30. Gas transport in body • Oxygen is carried by hemoglobin in the RBCs

32. Respiratory Control Centers • Brainstem

33. Respiratory Pathology • Carbon Monoxide Poisoning • From combustible fuel • Carbon monoxide binds to hemoglobin much faster than does oxygen • Death is due to lack of oxygen

34. Respiratory Pathology • Laryngitis is inflammation of larynx • Bronchitis is inflammation of bronchi – most chronic cases are due to smoking • Emphysema involves the alveoli • Alveoli become nonfunctional and are eventually destroyed • Irreversible change in alveoli • 80% of the cases are due to smoking

35. Respiratory Pathology • Cancer – 83% of cases are due to smoking • See normal & abnormal lungs:

36. Respiratory Physiology • Asthma • Usually due to allergies • Smooth muscle in smaller airways go into a spasm, thus closing smaller airways • Wheezing sound while breathing • Life-threatening condition • Treatment includes drugs that open airways

37. Respiratory Pathology • Pneumonia • Fluid-filled alveoli • Alveoli normally are filled with air • Mostly due to infection