Respiratory System

1. Respiratory System

2. Respiration • a single complete act of breathing in and out; "thirty respirations per minute" breathing • the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation

3. Structures of the Respiratory System • Upper Respiratory Tract • Nose • Pharynx • Larynx • Upper trachea • Lower Respiratory Tract • Lower trachea • Lungs • Bronchii • bronchioles

4. Nose & Nasal Cavities • Nasal Cavities • Conchae • Superior • Middle • Inferior

5. Pharynx • muscular tube posterior to the nasal & oral cavities • 3 parts • Nasopharynx – behind the nose • Soft palate – adenoids • Oropharynx – behind the mouth • Palentine tonsils • Laryngopharynx – most inferior; anterior is the larynx & posterior is esophagus

6. Larynx • Voice box • Connects the pharynx & the trachea • Made up of 9 pieces of cartilage • Thyroid cartilage • Epiglottis – uppermost cartilage • Mucosa has cilia that sweeps upward to remove mucus & trapped dust & microorganisms

7. Vocal Chords • Stratified squamous Epithelium • Air passes freely & move over the glottis to make sound

8. Trachea • Windpipe • 4 – 5 inches • 16 – 20 C shaped cartilage for protection • Thyroid Cartilage • Cricoid Cartilage • Tracheal Cartilage

9. Bronchi • Very similar to Trachea • Primary • Left – goes to the left lung • Right – goes to the right lung • Secondary – goes to each lobe • Similar to an upside down tree

10. Bronchioles • Smaller branches of bronchi • Does not have cartilage to keep it open • Terminates at alveoli

11. Lungs • What cavities are these located? • Left – 2 lobes • Right – 3 lobes • Parietal pleura – line the chest wall • Visceral pleura – surface of the lung • Serous fluid between for cushioning

12. Breathing • Ventilation – term for the movement of air to & from the alveoli • Inhalation (inspiration)– moving air in • Exhalation (expiration)– moving air out

13. Muscles involved in breathing • Diaphragm – contracts to flatten & allow the lung to move down • External intercostal muscles – ribs up & out • Internal intercostal muscles – downward & in • These muscles change the pressure within the alveoli & bronchial tree to cause VENTILATION

14. Pressures involved in Breathing • Atmospheric pressure – pressure in the air around us • Intrapleural pressure – pressure between the visceral & parietal pleuras • Intrapulmonic pressure – pressure within the bronchial tree & alveoli

15. INHALATION • The phrenic nerve stimulates the diaphragm to contract. When it does, it causes the chest cavity to expand (up & down). • The external intercostal muscles pull the ribs up & out (expands the chest side to side). • The parietal pleural expands with the chest causing NEGATIVE intrapleural pressure • Intrapulmonic pressure falls & causes air to rush into the nose (& lungs) until intrapulmonic & atmospheric pressure are equal

16. EXPIRATION • The diaphragm & the external intercostal muscles relax. The diaphragm returns to the “dome – shape” to decrease the size of the chest cavity • The elastic connective tissue of the lungs relaxes to squeeze the alveoli • Rising Intrapulmonic pressure (in the bronchial tree & alveoli) forces air out until it is equal with atmospheric pressure

17. Inhalation requires energy. The muscles have to contract to create negative pressure for air to enter the lungs. • However, normal exhalation is relaxation of the muscles & does not require your body to expend energy to do so. • The internal intercostal muscles have the ability to force air out of the lungs if needed.

18. Important values of the lungs • Tidal Volume – the amount of air involved in 1 normal inhalation & exhalation. Usually around 500 mL • Minute Tidal Volume – the amt of air inhaled & exhaled in 1 minute. • Inspiratory reserve – amt of air beyond the tidal volume that can be taken in with the deepest breath • Expiratory reserve – amount of air beyond tidal volume that can be expelled with the most forceful exhalation

19. Residual Air – air that remains in the lungs after the most forceful expiration to ensure that gas exchange continues to occur (between breaths)

20. Respiration • External – between the alveoli & capillaries • Internal – between capillaries & cells

21. Air we breath (FYI) • Air we inhale • 21% Oxygen • 78% Nitrogen • .04% Carbon Dioxide • Air we exhale • 78% Nitrogen • 16% Oxygen • 4.5% Carbon Dioxide

22. REFLEXES • Sneezing – triggered by an irritation of the nasal mucosa • Coughing – triggered by an irritation of the pharynx, larynx, or trachea • Both remove irritants from the respiratory tract

23. Hiccups • Spasms of the diaphragm • Glottis snaps shut causing the “hic” sound • Usually due to an irritation of the phrenic nerve or stomach nerves

24. Yawning • No certain cause of yawning. • Possibilities • Tiredness • Lack of O2 • Increased CO2 NO ONE KNOWS WHY YAWNING IS CONTAGIOUS. DO YOU NEED TO YAWN RIGHT NOW, JUST DISCUSSING IT???

25. DISEASE • Asthma • Usually caused by allergies or irritants • Affects the smooth muscles & glands of the bronchioles • Symptoms: • Wheezing • Dyspnea (difficulty breathing) • Treatment: • Medication

26. Pneumothorax • Caused by pressure in the pleural space which causes the lungs to collapse • Usually results from trauma (open space in chest wall) will allow atmospheric pressure (air from the outside) to enter the pleural cavity

27. Pneumonia • Caused by bacteria. Can you take antibiotics? • Caused Streptococcus pneumoniae • Bacteria sets up in the alveoli sacs • This causes the alveoli to secrete fluid (then neutrophils arrive) • Resulting in decreased gas exchange

28. Carbon Monoxide • CO • Colorless, odorless gas • It attaches to hemoglobin faster than O2 • Develop hypoxia & cyanosis