1. RESPIRATORY SYSTEM *Gas exchange between the atmosphere and cells.

3. FUNCTIONS Obtain O2 Excrete CO2 Filter incoming air
Control temperature and water content of air
Produce vocal sounds
Smell
Blood pH

4. ORGANS Upper respiratory tract Nose Made of bone and cartilage
Hairs prevent entry of large particles

5. Nasal Cavity Hollow space behind nose
Septum divides into right and left portions
Conchae divide passageway and support mucus membrane
Mucus membrane produces mucus that entraps small particles that is then swallowed and digested.
Mucus membrane moistens air
Blood vessels release heat from blood to warm
incoming air

6. Paranasal Sinuses Pharynx (throat) Air filled sacs
Lined by mucus membrane
Reduce the weight of the skull
Resonant chambers affect sound of voice
Pharynx (throat)
Air passageway
Helps produce sounds of speech

7. Lower Respiratory Tract
Larynx
Enlargement below pharynx
Conducts air in and out of trachea
Prevents foreign objects from entering trachea
Houses vocal cords
Composed of cartilage and muscle
Thyroid is the largest (Adam’s apple)
Glottis: opening within vocal cords
Epiglottis: flap-like structure that covers larynx

8. Trachea (windpipe) Bronchial Tree
Flexible cylinder tube 2.5 cm in diameter
Anterior to esophagus
C- shaped pieces of hyaline cartilage rings
Lining has ciliated mucous membrane with goblet cells to filter air.
Bronchial Tree
Branched airways leading from trachea to alveoli in lungs
Bronchii bronchioles alveolar ducts alveolar sacs alveoli
Alveoli: small sacs where gases diffuse in and out of blood in capillaries

9. Trachea
Bronchioles
Bronchii
Bronchioles
Alveoli ducts
Alveoli sacs
Alveoli

10. Lungs Soft, spongy, cone-shaped
Suspended in thoracic cavity by bronchus and blood vessels
Visceral pleura; parietal pleura; pleural cavity
Right lung – larger, 3 lobes
Left lung - 2 lobes

11. Healthy Lung Smokers Lung

12. BREATHING MECHANISM Inspiration (inhalation)
Atmospheric pressure due to the weight of air is the force that moves air into the lungs.
Low pressure inside alveoli and lungs-atm pushes outside air in and visa versa
Impulses in phrenic nerves stimulate the diaphragm to contract
Intercostals muscles contract
Surfactant: mixture of lipids and proteins made by alveolar cells that reduces the alveoli’s tendency to collapse. (respiratory distress syndrome in premature infants lack this and may be injected)

13. Expiration (exhalation)
Passive process due to elastic recoil
Air volumes and capacities (table pg. 457)
Spirometry: measure air volume (spirometer)
1 inspiration + 1 expiration= 1 respiratory cycle
Tidal volume: amount of air that enters/leaves in one respiratory cycle (500ml)
Inspiration reserve volume: extra volume from forced air (3,000 ml)
Expiration reserve volume: 1,100 ml extra with residual volume left over (1,200 ml)
Medulla and Pons are the 2 main respiratory centers

14. Factors affecting breathing
Emotional state
Hyperventilation: breathing rapidly and deeply lowering blood CO2 levels
Physical activity

15. Problems and Others
Nonrespiratory movements: used to clear air passageways
Coughing: clear from lungs
Sneezing: irritation in nasal cavity that forces air through glottis up to 200mph
Laughing
Crying
Hiccup: sudden inspiration due to a spasmodic contraction in diaphragm (function is not known)
Yawn: triggered by low blood O2

16. Atelectasis: collapsed lung
Emphysema: progressive, degenerative disease that destroys alveolar walls
Lung cancer: uncontrolled division of abnormal cells that rob normal cells of nutrients and O2
Hypoxia: deficiency of O2 reaching tissues
Cystic fibrosis: genetic disorder that causes a formation of extremely thick, sticky mucus, which encourages infections by microorganisms