1. RESPIRATORY SYSTEM

2. Standard: HS-EHS-5
5.1 Analyze the basic structures and functions of the respiratory system.

3. RESPIRATORY SYSTEM Consists of lungs and air passages
Responsible for taking in oxygen and removing carbon dioxide
Body has only 4-6 minute supply of O2
Respiratory system must work continuously or death will occur

4. RESPIRATORY SYSTEM PARTS
Nose
Pharynx
Larynx
Trachea
Bronchi
Alveoli
Lungs

5. NOSE Nostrils (nares) Nasal septum Openings through which air enters
Partition or wall of cartilage
Divides nose into two hollow spaces called nasal cavities

6. NASAL CAVITIES Lined with mucous membrane Have a rich blood supply
As air enters cavities, it is warmed, filtered, and moistened
Mucus, produced by the mucous membranes, also helps trap pathogens (germs) and dirt

7. NASAL CAVITIES (CON’T)
Cilia
Tiny hair like structures in nasal cavity
Filter inhaled air
Traps dust & pathogens as they enter nose so the particles can be pushed toward the esophagus and swallowed
Olfactory receptors are located in the nose

8. SINUSES Cavities in skull around nasal area
Connected to nasal cavity by short ducts
Provide resonance for voice

9. PHARYNX (THROAT) Lies directly behind nasal cavities
As air leaves nose it enters the pharynx
Three sections
Nasopharynx
Upper portion behind nasal cavities
Pharyngeal tonsils, eustachian tube openings
Oropharynx
Middle section
Behind oral cavity
Receives air from nasopharyx and food and air from mouth

10. PHARYNX (CON’T) Laryngopharynx Bottom section of pharynx
Branches into trachea, which carries air to and from the lungs and esophagus, tube that carries food to stomach

11. LARYNX Voice box Between pharynx & trachea
Has “Adam’s apple” (framework of cartilage)
Contains two folds Vocal cords
As air leaves lungs, vocal cords vibrate to produce sound
Tongue and lips act on sound to produce speech

12. LARYNX (CON’T) Epiglottis
Leaf like structure that closes the opening into the larynx during swallowing
Prevents food & liquids from entering the respiratory tract

13. TRACHEA “Windpipe” Extends from larynx to center of chest
Carries air b/t pharynx and bronchi

14. BRONCHI Two divisions of trachea near center of the chest
Right bronchi shorter, wider, and extends more vertically
Continue to divide into smaller and smaller bronchi
Smaller branches = bronchioles
End in “air sacs,” or alveoli

15. ALVEOLI Resemble a bunch of grapes Approx. 500 million in adult lung
Contain a rich network of capillaries
Capillaries allow oxygen and carbon dioxide to be exchanged between blood and lungs
Inner surface covered with surfactant
Fatty substance that keeps alveoli from collapsing

16. Alveoli

17. LUNGS Organs that contain divisions of bronchi and alveoli
Right lung has 3 lobes superior, middle, inferior (upper, middle, lower)
Left lung has 2 lobes superior & inferior (upper & lower)
Smaller because the heart lies more to the left

18. LUNGS (CON’T) Pleura Membrane or sac enclosing each lung Pleural space
Visceral pleura is attached to surface of lung
Parietal pleura attached to chest wall
Pleural space
Located b/t the two layers
Filled with thin layer of pleural fluid that lubricates membranes and prevents friction as lungs expand during breathing

19. VENTILATION , A.K.A. “BREATHING”
Inspiration & expiration (see vocabulary terms)
Diaphragm and intercostal muscles (between ribs) contract to expand thoracic cavity during inspiration
Diaphragm and intercostal muscles relax to collapse the thoracic cavity during expiration.

20. VENTILATION (CON’T) Respiration controlled by medulla oblongata
Decreased oxygen or increased carbon dioxide increased respirations

21. Write Q&A to the following questions.
What is Epistaxis?
List all of the different causes for epistaxis.
Which populations are most at risk?
How is it treated?
How do you avoid it?
What is the prognosis?