1. Breathing

2. Water is necessary in the membranes of the lungs so that
diffusion can take place. Water lost through breathing must
constantly be replenished by taking in water.
http://www.google.ca/imgres?q=composition+of+inhaled+air+vs+exhaled+air&hl=en&sa=X&rls=com.microsoft:en-ca:IE-
SearchBox&rlz=1I7TSCA&biw=1600&bih=639&tbm=isch&prmd=imvns&tbnid=KiwIIrShpgcxqM:&imgrefurl=http://budakpintar-zulaikha.blogspot.com/&docid=lbTWRCyBy-
6lnM&imgurl=http://4.bp.blogspot.com/-
SaThBr3gZ48/TZSnBrPGVoI/AAAAAAAAADM/dg2amBg4PVU/s1600/000.jpg&w=1221&h=745&ei=Y4PjTvX4I4jhiAKjuoS_Bg&zoom=1&iact=hc&vpx=170&vpy=346&dur=22745&hovh=175&hovw=288&tx=193
&ty=152&sig=112479492059546291295&page=1&tbnh=117&tbnw=192&start=0&ndsp=23&ved=1t:429,r:15,s:0

3. See the video:
http://www.youtube.com/watch?v=sU_8juD3Y
zQ&feature=player_embedded
http://www.google.ca/imgres?q=inhaled+air+vs+exhaled+air&hl=en&sa=X&rls=com.microsoft:en-ca:IE-
SearchBox&rlz=1I7TSCA&biw=1600&bih=639&tbm=isch&prmd=imvns&tbnid=DXuImWah7HIOMM:&imgrefurl=http://www.webmd.com/lung/picture-of-the-
lungs&docid=7F7zvNw2FVzXiM&imgurl=http://img.webmd.com/dtmcms/live/webmd/consumer_assets/site_images/articles/image_article_collections/anatomy_pages/Lungs_AnatomyPage2.jpg&w=504&h=378&ei=
1YHjTqvuCciQiALnvPnQBg&zoom=1&iact=rc&dur=577&sig=112479492059546291295&page=1&tbnh=137&tbnw=182&start=0&ndsp=24&ved=1t:429,r:11,s:0&tx=104&ty=58

4. How Gas Exchange Occurs

5. Air is moved by pressure differences due to volume differences.

6. 1. Diaphragm contracts
and intercostal
muscles contract.
Ribs move up.
2. Volume of thoracic
cavity increases.
3. Pressure of thoracic
cavity drops to LESS
than outside air
pressure. (pressure
outside > pressure
inside)
4. Air moves in through
the mouth and nose.

7. 1. Diaphragm relaxes
and recoils.
Intercostal muscles
relax. Ribs move
down.
2. Volume of thoracic
cavity decreases.
3. Pressure of the
thoracic cavity rises
relative to the
outside pressure.
(pressure inside >
pressure outside)
**THE LUNGS ARE PASSIVE. DIAPHRAGM AND
4. Air moves out INTERCOSTAL MUSCLE MOVEMENT CAUSES
through mouth and CHANGES IN VOLUME AND THEREFORE PRESSURE,
nose. WHICH CAUSES THE LUNGS TO EMPTY OR FILL WITH
AIR.

8. Mechanism of Breathing Explained:
Explained:
http://www.youtube.com/watch?v=IMDEXGM-
87s
Simple breathing animation:
http://www.youtube.com/watch?v=43jJGXude
Ps&feature=related

9. Lung Capacity

10. Fig. 15.5

11. Lung Capacity
5800 L
2900 L
2400 L
1200 L
0L
http://www.google.ca/imgres?q=inhaled+air+vs+exhaled+air&hl=en&sa=X&rls=com.microsoft:en-ca:IE-
SearchBox&rlz=1I7TSCA&biw=1600&bih=639&tbm=isch&prmd=imvns&tbnid=oMyRkQg7Jrce0M:&imgrefurl=http://www.rcjournal.com/cpgs/slvcpg-
update.html&docid=PRFksORYx0p7sM&imgurl=http://www.rcjournal.com/cpgs/i/05.01.0531.fig1.jpg&w=580&h=336&ei=1YHjTqvuCciQiALnvPnQBg&zoom=1&iact=hc&vpx=1258&vpy=159&dur=187&hovh=171&hov
w=295&tx=186&ty=95&sig=112479492059546291295&page=1&tbnh=103&tbnw=178&start=0&ndsp=24&ved=1t:429,r:7,s:0

12. Gas Exchange

13. External Respiration Internal Respiration Cellular Respiration
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0bSngOQhPyM:&imgrefurl=http://www.ric.edu/faculty/jmontvilo/335files/335(27)respirationmech.htm&docid=Uf1ASTwnOH0U7M&imgurl=http://www.ric.edu/faculty/jmontvilo/335graphics/gas_exchange.GIF&w=
502&h=346&ei=X5DjTuHgIa_-iQKmsYyfBg&zoom=1&iact=rc&dur=499&sig=112479492059546291295&page=5&tbnh=116&tbnw=169&start=101&ndsp=26&ved=1t:429,r:10,s:101&tx=110&ty=68

14. Transport of Gases

15. Oxygen Transport
Two ways:
1. As a physical solution. (Dissolved in plasma.)
2. As a molecule of hemoglobin.
Hb + O2 HbO2

16. Carbon Dioxide Transport
Three ways:
1. As a physical solution in plasma. (<5%)
CO2 + H2 H2CO3 H+ + HCO3-
Very slow reaction. Carbonic anyhdrase is not present in plasma.

17. 2. Carbaminohemoglobin. (10 – 30%)
Hb + O2 HbO2
Rapid.
Requires no enzyme.

18. http://www.google.ca/imgres?q=transport+of+oxygen&hl=en&safe=active&sa=X&rls=com.microsoft:en-us:IE-
SearchBox&biw=792&bih=450&tbm=isch&prmd=imvns&tbnid=E8W0rpVvx6T0oM:&imgrefurl=http://schoolworkhelper.net/2010/07/oxygen-carbon-
transport/&docid=xwb_qPOsukdwRM&imgurl=http://schoolworkhelper.net/wp-content/uploads/2010/07/carbon-transport.jpg&w=480&h=360&ei=rBLQTrTBHqGMigL-
g8X7Cw&zoom=1&iact=rc&dur=157&sig=116001018724518129899&page=1&tbnh=120&tbnw=160&start=0&ndsp=8&ved=1t:429,r:7,s:0&tx=84&ty=82

19. 3. As a bicarbonate ion (60 – 70%).
Involves the plasma and red blood cells.

20. 1. At the red blood cells, carbon dioxide and water react IN THE PRESENCE OF CARBONIC
ANHYDRASE, to produce carbonic acid.
2. Carbonic acid dissociates into a hydrogen ion and bicarbonate ion. Bicarbonate ion diffuse
into the plasma.
3. Hydrogen ions displace oxygen on the oxyhemoglobin. Reduced hemoglobin and free
oxygen are produced.

21. 4. Oxygen diffuses out of the capillary to the body cells.
5. Cellular respiration. Oxygen reacts with glucose to produce carbon dioxide and water.
6. Carbon dioxide diffuses into the blood.

22. 7. Oxygen diffuses from the alveoli to the red blood cells in the capillary.
8. Oxygen displaces hemoglobin on reduced hemoglobin to produce hydrogen ions and
oxyhemoglobin.
9. Hydrogen ions combine with bicarbonate ions (which diffuse from the plasma) to produce
carbonic acid.
10. Carbonic acid is converted to water and carbon dioxide in the presence of CARBONIC
ANYHDRASE.
11. Carbon dioxide diffuses out of capillaries and into alveoli.

23. Control of Breathing by the Nervous System
Breathing
Chemoreceptors centre on
medulla Diaphragm / rib
at aorta and
Blood oblongata muscles
carotid artery
Stimulation Activity Activity
Carbon dioxide
concentration
(-)