1. The Respiratory System

2. Major Function of Resp. System
Supply the body with Oxygen
Dispose of Carbon dioxide

3. Functional Anatomy – 2 zones
Respiratory zone:
Actual site of gas exchange occurs in the alveoli

4. Functional Anatomy – 2 zones
Conducting zone:
Conduits – purify, humidify, and warm incoming air
Include all other respiratory passageways

5. Nose – 5 functions Provide airway for respiration Moisten & warm air
Filter air (mucus & cilia) (breath in thru nose & out thru mouth)
Site of olfactory (smell) receptors
Resonating chamber for sound waves (hold your nose closed & see how you sound!)

6. Cold day = Runny nose
The cilia in your nose become sluggish & slow when they are cold & do not move the mucus down into your throat
Mucus in the nasal cavity accumulates & dribbles out

7. Nasal Conchae Nasal Conchae
increase surface area of mucosa exposed to air
increase turbulence (mini tornado effect) of air

8. Nasal Cavity
Nasal cavity separated from oral cavity by the palate (roof of mouth)
Anterior – hard palate
Posterior – soft palate

9. Paranasal sinuses functions
Lighten skull
Act a resonance chamber
Produce mucus

10. Check this out! (do not try this at home or in this classroom!)
The Human Blockhead

11. Pharynx
Pharynx serves as common passageway for food (& fluids) and air.

12. Pharynx – 3 basic parts Nasopharynx – air only
During swallowing, Soft palate & uvula rise upward to close off nasopharynx which prevents food & fluids from entering it
Oropharynx -the part of the pharynx that lies between the soft palate and the hyoid bone.
Laryngopharynx – food, liquids & air
Food will be directed posteriorly to the esophagus
Air will go anteriorly into the larynx

13. Tonsils (think about the name – it tells you the location)
Pharyngeal tonsils: aka. Adenoids – located in nasopharynx
Palatine tonsils: located in oropharynx
Lingual tonsils: located at base of tongue
All tonsils are lymph nodes & work with immune system

14. Larynx – 3 Functions Provides patent (open) airway
Act as a switching mechanism (between respiratory & digestive systems)
Voice production (location of vocal cords)
Click here for a video

15. Adam’s apple Laryngeal prominence on the thyroid cartilage
Seen externally as Adam’s apple

16. Epiglottis 9th cartilage
When air is flowing into the larynx – free edge projects upward
During swallowing:
Larynx is pulled upward
Epiglottis is tipped back and down to cover laryngeal inlet into trachea
Routes food/fluid into esophagus

17. Cough Reflex Initiated if anything other than air enters the larynx
Pressure from air moves object upward out of the larynx
Reflex does not work when unconscious so not a good idea:
To give fluids to an unconscious person
Also a reason why people in an alcoholic coma often die from aspirating their own vomit.

18. Trachea (Windpipe)
The ciliated mucosa (mucociliary escalator) continuously propels the mucus which contains dust particles and debris to the throat so it can be expelled or swallowed.

19. Smoking Diminishes ciliary activity
Coughing is ONLY method of preventing mucus accumulation in the lungs
Smokers should never be given medications that INHIBIT coughing

20. Some Effects of Smoking

21. Reinforcement Trachea is reinforced internally by 16-20 C shaped rings
Outer portion of C – causes trachea to stay patent (open) and not collapse
Inner portion (open part) of C – allow trachea to be flexible and gives esophagus a place to expand into upon swallowing.

22. Heimlich manuver is the same principle as a cough
Used to press air out of lungs

23. Tracheostomy -ostomy = cut a hole into Used in cases of: Abnormalities
Cancers
Obstructions
Injuries to area
Etc.

24. Bronchial Tree
Trachea divides into right and left primary bronchi at the level of the sternal angle (where manubrium and body of sternum meet).
Inhaled objects usually lodge in the right primary bronchus since it is wider, shorter, and at a more vertical angle

25. Lungs
Left lung is smaller, consisting of 2 lobes and contains a cardiac notch
Right lung has 3 lobes

26. FYI: Important Info
The lungs weigh approximately 2.5 pounds

27. The parietal pleura line the thoracic cavity wall while the visceral pleura line the external lung surface.

29. Pleurae: Review Function of pleural fluid
1. Lubricate layers so they can slide across each other
2. Cause them to cling tightly to each other through surface tension (helps maintain pressure differences necessary for inhaling/exhaling)

30. Respiratory Zone Structures
A. The respiratory zone is the only site of gas exchange Begins as the terminal bronchioles which feed into the respiratory bronchioles which end in the alveoli chambers

31. Alveoli
B. The alveolar walls are composed of simple squamous epithelium – much thinner than a sheet of paper
The respiratory membrane has gas on one side and blood on the other.

32. Alveoli C. Gas exchanges occur through the process of simple diffusion
Approximate surface area = square meters
D. Efficient gas exchange requires a moist membrane is required so cuboidal cells secrete a substance called surfactant that coats the membrane & interferes with surface tension.
Respiratory problems in premature infants