1. The Respiratory System
For a link to the Respiratory System of the Cat, click HERE

2. What are the functions of the Respiratory System?
1) Gas Exchange
2) Regulation of blood pH
pH:
3) Voice production
4) Olfaction
5) Innate immunity

3. Pathway of air during Inhalation & Exhalation
Breathe: Inspire + expire
Inspiration
Oral cavity/nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli, blood
Expiration
Exact reversal of inhalation

4. Organization of the Respiratory System
2 divisions:
Upper respiratory system: above the larynx
Lower respiratory system: from the larynx down

5. Components of the Respiratory System
Figure 23–1

6. Pharynx

7. The Nose & Nasal Cavity I. Nose II. Nasal Cavity
Air enters through nostrils or mouth
Nasal hairs: first particle filtration system (innate immunity)
II. Nasal Cavity
Mucous secretions: clean and moisten the nasal cavity
Olfactory region: provides sense of smell

8. III. The Pharynx A chamber shared by digestive and respiratory systems
Extends from internal nares to entrances to larynx and esophagus

9. The Epiglottis Composed of elastic cartilage Made of ligaments
Prevents food and liquids into respiratory tract
Back of pharynx

10. IV. Larynx Made up of cartilage & ligaments (vocal cords)
Forms what we call the Adam's apple

11. Sound Production Sound Variation Air passing: Sound is varied by:
vibrates vocal folds
produces sound waves
Sound Variation
Sound is varied by:
tension on vocal folds
voluntary muscles

12. V. The Trachea Also called the windpipe
branches into right and left pulmonary bronchi
Ciliated cells

13. VI. Bronchi… Smooth muscle Cartilage Cilia/mucous
Branch into bronchioles

14. Alveolar sac
Alveoli
Figure 23–2

15. Bronchitis Inflammation of bronchial walls:
causes constriction and breathing difficulty

16. The Respiratory Epithelium
For gases to exchange efficiently:
alveoli walls must be very thin (< 1 µm)
surface area must be very great

17. VII. Alveolar Organization
Respiratory bronchioles are connected to alveoli
300 million alveoli= 40x SA of skin!

18. The Lungs Left and right lungs: are in left and right pleural cavities
Pleura: secrete mucous, decrease friction
Rest on top of diaphragm

19. The Right Lung Has 3 lobes: superior, middle, inferior Wider
Above liver

20. The Left Lung
Has 2 lobes:
superior and inferior
Longer
Cardiac notch

22. Is this the way you want your lungs to look? DON’T SMOKE!!

23. The Respiratory Defense System
Consists of a series of filtration mechanisms
Removes particles and pathogens

24. Components of the Respiratory Defense System
Alveolar macrophages engulf small particles that reach lungs

25. Respiration External Respiration Internal Respiration
Exchange of gases with 2 processes:
External Respiration
All processes in exchanging O2 and CO2 with environment
Internal Respiration
Also called cellular respiration
Involves uptake of O2 and production of CO2 within individual cells

26. What physical principles govern the movement of air into the lungs?

27. Gas Pressure and Volume
Figure 23–13

28. Atmospheric Pressure Boyle’s Law
Relationship between gas pressure and volume:
As volume decreases, pressure increases
Balloon popping
In a contained gas:
Pressure is due to all molecules bumping into each other
Claustrophobic at a small party

29. Mechanisms of Pulmonary Ventilation
Inspire = Chest expands
—muscles contract (ribs out and up) & diaphragm goes down
--Decrease pressure (air in)
Figure 23–14

30. Mechanisms of Pulmonary Ventilation
2. Expire= chest flattens
Air forced out until pressures are equal

31. Pressures are equal –some air remains

32. Respiratory Performance and Age
Figure 23–28

33. Control of Respiration
Involuntary centers of the brain regulate breathing (__________receptors)
Sense pH in blood
Send message to increase rate and depth
Conscious thought tied to strong emotions (rage, fear) stimulate hypothalamus—affect breathing
Breathe more when cells work more