1. Respiratory System
Ch 23

2. Breathing (Pulmonary Ventilation) External Respiration
4 PROCESSES
Breathing (Pulmonary Ventilation)
External Respiration
Internal Respiration
Cellular Respiration

3. Sinus Cavity act as resonance chambers for speech
mucosa warms and moistens the incoming air
lightens facial bones

4. Pharynx Connects nasal cavity and mouth to larynx and esophagus
1)     nasopharynx- air passage
pharyngotympanic (auditory) tube- allows middle air pressure to become equalized to atmospheric pressure
Adenoids (pharyngeal) tonsils- mass of lymphoid tissue
traps and destroys pathogens
produces lymphocytes
helps fight infection
2)     oropharynx- serves as a common conduit for air and food
palatine and lingual tonsils
3)     laryngopharynx- accommodates both ingested food and air
located at junction where tracheae and esophagus splits
continuous with esophagus

5. Pharynx Epiglottis- flexible elastic cartilage
attached to the wall of the pharynx near the base of the tongue
it closes the glottis in the respiratory tract (trachea) when food is swallowed
Larynx- voice box; thyroid cart. that attaches to hyoid bone superior and cricoid inferior
Provides open airway
Junction for food and air
Voice production

7. Olfactory
epithelium
Olfactory tract
Olfactory bulb
Nasal
conchae
Route of
inhaled air

8. Trachea
16 C-shaped rings of hyaline cartilage (thyroid +cricoid + tracheal cartilage's, includes epiglottis (elastic cart) make up larynx
Laryngitis- inflammation of the vocal cords resulting in inability to speak; due to voice overuse, very dry air, bacterial infection, and inhalation of irritating chemicals
Trachea- held open by rings of hyaline cartilage, so it won't collapse during pressure changes when breathing.

9. Trachea

10. Epithelial Lining of the Trachea
mucus
cilia

11. Vocal Cords True vocal cords are inferior to false vocal cords
Sound is produced when expelled air is passing through the larynx over the vocal cords

12. Lungs

13. Alveoli

14. Alveoli

15. Alveoli

16. Thoracic Cavity

17. Thoracic Cavity

18. Partial
Pressure
Gradients

19. Ventilation-Perfusion Coupling

20. Mechanics of Breathing
2 muscles involved with breathing:
external intercostal muscles
diaphragm
Breathing controlled by:
phrenic nerve from medulla
pons

21. Lung Ventilation Negative pressure draws air in Inspiration 760 mm Hg

22. Lung Ventilation
Positive pressure forces air out
768 mm Hg
Expiration

23. Lung Volumes Tidal Volume- 500 ml Vital Capacity- 4800 ml
Residual Volume ml
Total Lung Capacity ml
IRV ml
ERV ml
Dead Space- 150 ml
TV- tidal volumes- normal breathing ~500 ml air
IRV- inspiratory reserve volume- amount of air that can be forcefully inhaled after a normal tidal volume inhalation ~3100 ml
ERV- expiratory reserve volume- amount of air that can be forcefully exhaled after a normal tidal volume of exhalation ~1200 ml
VC- vital capacity- total amount of exchangeable air; maximum amount of air that can be forcefully exhaled after a maximal inspiration ml
VC=TV + IRV +ERV
RV- residual volume = air that helps keep alveoli open and prevents lung from collapsing ~1200 ml
TLC- total lung capacity = TV+IRV+ERV+RV
Dead space- air that never contributes to gas exchange ~ conduit ~150 ml; throat, alveoli, nasal passage
What factors affect lung volume?

25. What happens to TV, IRV, ERV, & VC during exercise?
IRV and ERV 
TLC and VC- doesn't change

26. Breathing Centers in the Brain

28. Regulation of Breathing
medulla oblongata
pons
phrenic
CO2 and H+ triggers breathing reflex in medulla, not presence of O2
vagus

31. Restrictive vs Obstructive Air Flow
Restrictive- more diff. to get air in to lungs
Loss of lung tissue
Decrease in lungs ability to expand
Decrease in ability to transfer O2 and CO2 in blood
Diseases:
Fibrosis, sarcoidosis, muscular disease, chest wall injury, pneumonia, lung cancer, pregnancy, obesity
 VC, TLC, RV, FRC

32. Restrictive vs Obstructive Air Flow
Obstructive- more diff. to get air out of lungs
Airway narrows
Increase in time it takes to empty lungs
Diseases:
Emphysema, chronic bronchitis, asthma
 VC,  TLC, RV, FRC

33. Chronic
Obstructive
Pulmonary
Diseases

34. COPD
Chronic bronchitis- (obstructive) inhaled irritants lead to chronic excessive mucous production and inflammation and fibrosis of that mucosa;  the amt of air that can be inhaled; use bronco- dilators and inhalers
Emphysema- (obstructive and restrictive) enlargement of alveoli; alveolar tissue is destroyed resulting in fewer and larger alveoli; inefficient air exchange; smoker's disease;  amt of air that can be exhaled
Asthma- (obstructive disorder) cold, exercise, pollen and other allergens; from the number of asthmatic deaths doubles

35. COPD
Tuberculosis (TB)- (restrictive) infectious disease cause by bacterium Mycobacterium tuberculosis. Spread through air borne bacteria from infected person's cough. Total lung capacity declines
Symptoms: fever night sweats, wt. loss, racking cough, and spitting up blood
Polio- TLC declines (restrictive)
Eliminated in U.S. and Western Hemisphere
Still exists in Africa
Lung cancer- promoted by free radicals and other carcinogens; very aggressive and metastasizes rapidly

36. Smoker’s lung
Normal lung

37. Dalton's Law of Partial Pressure
The total pressure of a gas exerted by a mixture of gas is the sum of the gases exerted independently.
Air % partial pressure (mm Hg) N O CO
H2O
Total
Dalton's law states that the individual gases of any gas mixture will have the same pressure alone or as part of the mixture. Thus, at sea level, the oxygen component of air by itself will support a mercury column mm high, and the nitrogen component will support a mercury column mm high.
At depth all pressures increase, for both air as a mixture and for its component gases. For example, a doubling of ambient air pressure, which occurs at just 33 fsw, will double the partial pressure of oxygen, nitrogen, and other component gases. At 66 fsw, the ambient pressure is tripled, along with the partial pressure of oxygen, nitrogen and other gases inhaled at that depth.
Partial pressure is directly related to its % in the total gas mixture. E.g., at 1 atm PO2 = 159 mm Hg

38. Henry's Law
When a mixture of gas is in contact w/a liquid, each gas will dissolve in the liquid in proportion to its partial pressure.
Gasses can go in and out of solution
e.g., open soda, get CO2 bubbles (CO2 is under pressure)

39. Decompression Sickness
It is caused when N2 enters the blood circulation and the tissues.
When extra N2 leaves the tissues, large bubbles form. N2 bubbles can travel throughout the system and into the lungs and blood routes.
Treatment: hyperbaric chamber
The increased pressure of each gas component at depth means that more of each gas will dissolve into the blood and body tissues, a physical effect predicted by Henry's Law. To review, Henry's law states that the amount of gas dissolving into any liquid or tissue with which it is in contact is proportional to the partial pressure of that gas. Inhaled gases are in close contact with blood entering the lungs. Hence, the greater the partial pressure of any inhaled gas, the more that gas will diffuse into the blood.
Together, Boyle's and Henry's laws explain why, as a diver descends while breathing compressed air:
1) inhaled PO2 and PN2 increase and
2) the amount of nitrogen and oxygen entering the blood and tissues also increase.

40. Erythrocytes Function- transport respiratory gases
Lack mitochondria. Why?

41. Hemoglobin Structure Hemoglobin- quaternary structure
2  chains and 2  chains
Hemoglobin Structure
1 RBC contains 250 million hemoglobin molecules

42. Uptake of Oxygen by Hemoglobin in the Lungs
O2 binds to hemoglobin to form oxyhemoglobin
High Concentration of O2 in Blood Plasma
High pH of the Blood Plasma

43. O2 pickup CO2 release

44. Unloading of Oxygen from Hemoglobin in the Tissues
When O2 is releaseddeoxyhemoglobin
Low Concentration of O2 in Blood Plasma
Lower pH of the Blood Plasma

45. O2 release CO2 pickup

46. Carbon Dioxide Chemistry in the Blood
CO2 + H2O  H2CO3  HCO H+
bicarbonate
ion
carbonic
acid
enzyme = carbonic anhydrase

47. Transport of Carbon Dioxide from the Tissues to the Lungs
60-70% as bicarbonate dissolved in the
plasma (slow reaction)
7-10% dissolved in the plasma as CO2
20-30% bound to hemoglobin as HbCO2
CO2 + hemoglobin  HbCO2

48. Haldane Effect
Haldane Effect- the amt of CO2 transported in the blood is markedly affected by the degree of oxygenation of the blood
The lower the P02 and hemoglobin saturation w/O2, the more CO2 that can be carried by the blood

49. Carbon Monoxide Poisoning
CO poisoning (hypoxemia hypoxia)
CO binds 200x more readily w/hemoglobin
acts as a competitive inhibitor
symptoms: cherry red lips, confused, headache
does not produce characteristic signs of hypoxia (cyanosis and respiratory distress)
treatment: hyperbaric chamber

50. INQUIRY
Identify the lipoprotein molecule that reduces surface tension within the alveoli so they do not collapse during exhalation.
Even after the most forceful exhalation, a certain volume of air remains in the lungs. What is the volume of air called?
Describe the physical structure of alveoli.
What structures warm and moisten incoming air?
What body cavity are the lungs located?
What tissue lines the lungs?
What stimulates the breathing response?
Calculate total lung capacity given:
RV= 1000, TV = 500, ERV = 1100, IRV = 2500, VC= 4100