1. Respiratory System
Ch 22

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
Eustatian tube
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
Larynx- voice box; thyroid cart. that attaches to hyoid bone superior and cricoid inferior
Provides open airway
Junction for food and air
Voice production

6. Pharynx
Nasopharynx
Oropharynx
Laryngopharynx

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

9. Trachea
16 C-shaped rings of hyaline cartilage (thyroid +cricoid + tracheal cartilage's, includes epiglottis (elastic cart) make up larynx
Function- hold trachea open
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

10. The Trachea lumen posterior anterior esophagus hyaline cartilage ring
Mucus membrane
submucosa
adventitia
anterior

11. Trachea

12. The Trachea

13. Epithelial Lining of the Trachea
mucus
cilia

14. 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

15. Lungs

16. Alveoli

17. Alveoli

18. Alveoli

19. Thoracic Cavity

20. Thoracic Cavity

21. Partial
Pressure
Gradients

22. Ventilation-Perfusion Coupling

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

24. Mechanics of Breathing

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

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

27. Lung Volumes Tidal Volume- 500 ml Vital Capacity- 4800 ml
Residual Volume- 1200ml
Total Lung Capacity ml
IRV ml
ERV- 1200ml
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?

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

30. Breathing Centers in the Brain

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

34. 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

35. 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

36. Chronic
Obstructive
Pulmonary
Diseases

37. 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

38. 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

39. Smoker’s lung
Normal lung

40. 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

41. 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)

42. 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.

45. Hyperbaric Chamber

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

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

48. 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
oxyhemoglobin O2

49. O2 pickup CO2 release

50. 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

51. O2 release CO2 pickup

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

53. 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

54. 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 PO2 and hemoglobin saturation w/O2, the more CO2 that can be carried by the blood.

55. 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

56. Mammalian Dive Reflex Heart rate slows
Blood flow to extremities constricted
Blood and water allowed to pass through organs and circulatory walls to chest cavity.
The first two items begin to happen as soon as the face hits cold water. The slowing heart rate is almost instantaneous, the constricted blood flow happens more gradually. Both responses are more extreme with more extreme temperatures. The slowed heart rate is generally a useful feature as it actively serves to conserve oxygen depletion and increase the available time underwater without dramatically harming performance. Yeah! You’re holding your breath, so obviously there are limits to the effectiveness! The decreased blood flow provides more of a long-term (minutes-hours) survival benefit, but is detrimental to performance. If you were diving for food, you’d quickly find that your limbs turn into numb rocks in cold water.
The third response is a bit more scary. Essentially, the body intentionally allows fluid to fill the lungs and chest cavity to prevent organs from being crushed from extreme pressure. For surface dwelling mammals, this serves a survival function. It only kicks in as depths become extreme.
Mammalian Dive Reflex
First observed in sea mammals, this reflex (MDR) is effectively what allows freedivers to do what they do. It wasn't until the 1950's that this reflex was shown to be possessed by people and not just whales, seals and our cretacious cousins, the dolphins.
Prior to this discovery and even in the era of Jaques Mayol, scientists thought it was impossible for a freediver to dive much over 40m without being killed. The MDR consists of a number of immediate physiological changes: bradycardia (the slowing of the heart), splenic contraction and blood shift.
a) Bradycardia (slowing of the heart)
Because the heart, as the biggest muscle in the body, uses oxygen every time it beats, the slower it beats, the less oxygen it uses, allowing the diver to stay underwater for extended periods.
b) Splenic contraction
Water pressure squeezes the spleen, reducing its size by up to 20%. This effectively squeezes blood rich in red blood-cells into the circulatory system, increasing hemoglobin concentration by up to 10%.
c) Blood shift
Blood shift, or "blood shunt", is a movement of blood from the peripheral areas such as the limbs, to the core areas of heart, lungs and brain. It is caused through peripheral vasoconstriction of skin vessels, as well as big intra-thoracic vessels. For these organs, oxygen is an obvious priority. So by this redistribution of blood, and therefore oxygen, from the nonessential areas to those areas involved in maintaining consciousness, the freediver is able to stay conscious longer. Another advantage offered by blood shift is that, because there is less blood flowing to the legs, when they are used during fining they are forced to work primarily anaerobically and therefore use less oxygen than they otherwise would.
Blood shift also allows divers do dive well beyond residual volume (30-40m) without suffering "lung squeeze" as the lungs pool with blood, thereby mitigating the increasing vacuum effect caused by ribs inability to flex inwards and the diaphragm to move up as the pressure differential between the air in the lungs and the surrounding water increase. Blood does not actually enter the lungs air space. Rather it is the capillaries that intrude into the lungs' airspace and expand as they become engorged with blood. This is termed "pulmonary erection". Only if negative pressure becomes extreme will plasma and then even blood (pulmonary edema) enter the airspace and be coughed up.
Martin Stepanek, during static apnea alone, is said to have such a strong blood shift that his legs and arms go visibly white and his torso red. This shows that although blood shift is usually triggered by pressure, it is also triggered by the "breath-hold reflex", the two reflexes being inextricably linked.
The degree of dive reflex:
It varies from person to person. Fortunately it is trainable to a large degree. The more often you dive, the more accustomed the body gets to engage the various mechanisms involved.
It's almost as if the brain, knowing what is about to happen next, can quicker and more effectively trigger the necessary physiological chances. A simple static then becomes enough to trigger the entire MDR.
Facial immersion:
Apart from increased ambient hydrostatic pressure and breath-holding, the other very important trigger of the MDR is facial immersion in water.
Dr Erica Schagatay found that the main trigger was cold water, colder the better. She also managed to show that the areas which needed to be exposed to the cold water were on the face, specifically nerves around the eyes and upper lip.
This is the reason behind doing a warm-up static face down and without a mask before a big dive, and if there is a thermocline available, a static bellow the thermocline without a mask. It's also the reason why many freedivers prefer wearing goggles over masks during statics.

57. Hyperventilation
Short term, rapid, deep breathing beyond the need for the activity
Lowers the level of CO2 in blood (hypocapnia or hypocarbia)
Short term, rapid, deep breathing beyond the need for the activity
Lowers the level of CO2 in blood (hypocapnia or hypocarbia)

58. Shallow Water Blackout

59. 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