BIOL 208 Lecture Notes - Lecture 13: Carbonic Anhydrase, Red Blood Cell, Blood Plasma
***SUPPLEMENT 9B***
● have blood leaving the tissue, PO2 is 40 (normal PO2 is around 105)
● partial pressure of oxygen is high, leaving the lungs and by the time it leaves the tissues its
down to 40, not to 0, but 40. still some oxygen in your blood by the time it leaves
● now that oxygen is going to replenished, that hemoglobin that is left allows for the oxygen to
leave the hemoglobin, most of it, now its got to make its way back from all of the different
veins into the right atrium and then into the pulmonary artery to the lungs, oxygenated, come
back, and then it comes back at 105
● its a cycle
● oxygenation occurs in the capillaries, starts at 40, ends up at 105. leave, go to different blood
vessels until finally you get to the tissues, internal respiration, arteriole taking you to the
tissues
● will go over further later
***SUPPLEMENT 10*** (will go over much further later)
● so start with a tissue, and CO2 leaves
● once CO2 gets into plasma, have 2 options
● 7% of CO2 remains dissolved
● remainder of CO2 goes into a red blood cella and only in the red blood cell is going to be
responsible for most of the transportation of CO2
● 3 options; some remains dissolved in fluid of RBC, some goes and latches onto hemoglobin,
most of the CO2 is going to form with H2O in the presence of CAD (carbonic anhydrase),
bringing about carbonic acid. carbonic acid itself is going to separate into hydrogen ion,
bicarbonate ion, and this hydrogen ion itself has 2 options to either attach to hemoglobin or
go outside and be involved in proteins
● bottom line is H2O is going to be removed from RBC and most of CO2, 70% is going to be
transported in the blood plasma as bicarbonate ions
● rest either attach to hemoglobin or is dissolved in the plasma
● if you have a lot of O2 coming into tissues, the high amount of CO2 in realm facilities
unloading. similarly when you have a lot of CO2 coming from the tissues going to the lungs,
the high amount of oxygen in the lungs facilities unloading of carbon dioxide. help each other
Dead space/dead volume
***the part of the respiratory pathway in which gas exchange does not take place***
● this basically is the conducting zone
● may be areas where gas exchange normally occurs but doesn’t, so that becomes dead
space as well
● 2 kinds of dead spaces;
● 1) anatomical dead space (ADS);
● space in respiratory tract where ordinarily no gas exchange (CZ)
● 2) physiological dead space (PDS); (total dead space (TDS))
● is the anatomical dead space (ADS) + the volume of any non-functioning alveoli (= total dead
space (TDS))
find more resources at oneclass.com
find more resources at oneclass.com
● so total dead space is not only anatomical dead space, but any normal gas exchanging
pathways no longer functioning is called PDS or TDS
● so physiological dead space is not just whats not functioning, the PDS is what is usually
anatomical dead space plus what is not functioning, take them together, get total dead space
● normally, the physiological dead space = the anatomical dead space
● if lungs are functioning, space is the same. only if you are adding to it
● physiological dead space can be due to…
● 1) if certain alveoli collapse or if alveoli became filled with fluid (not completely filled, just
have some)
● these reduce normal gas exchanging surfaces
● 2) if blood supply to the lung is hindered, hampered, effected (either an embolism or is
inefficient (perfusion is poor))
● if you have an embolism going to lung, blood cant travel by alveolus, cant pick up
oxygen. no exchange. dead space
● if amount of blood flowing is not matched with the amount of air coming in and out, if
perfusion, blood flow, isn't synchronized properly with air going in and out of lung
there will be less of efficient ability for that blood going by that alveolus to pick up as
much oxygen as possible
● could be on capillary side where inefficiency, not only lungs themselves
MRV - Minute respiratory volume
● basically its equal to TV (500ml) X the number of breaths (12)
● multiply 12 X 500 = 6,000 (per minute)
● also called minute volume, and total ventilation
Hypoxia/anoxia
● low levels of O2 availability to the tissue
● different ways to say hypoxia to show where it is occurring
● if we have hypoxemia, the hypoxia is occurring in the blood. basically a reduced amount of
O2 in blood
● anemic-hypoxia is result of too few red blood cells or too little functioning hemoglobin.
example would be instead of having 5 million RBCs per cubic millimeter you only have 2,
meaning a lot of O2 not reaching tissues
Hypoxia
● low oxygen
● hypoxic conditions means limited amount of oxygen, stressful or damaging
● hypoxemia is low oxygen in the blood itself. blood itself has reduced amount of oxygen.
could be result of several things
● anemic hypoxia
● ischemic hypoxia is reduced amount of blood supply, therefore reduced oxygen
● ischemic/stagnant hypoxia could be the result of impaired or blocked circulation
● this impairment or blocked circulation, if you have coronary artery, 75% of its blocked with
plaque, so small amount still moving through but not efficiently enough. can be
painful/stressful, so forth. or a total block
● ischemic hypoxia is blood flowing to a particular area is diminished, usually partial, not
enough oxygen gets to the tissues
find more resources at oneclass.com
find more resources at oneclass.com
● the real hypoxia occurs in the tissues, these other terms describe the source of the hypoxia.
the blood may have low amount of oxygen because of the deficient hemoglobin or whatever
reason. these are the sources for ultimate inability to deliver oxygen to the tissues, and its
the tissues that are hypoxic
● histotoxic hypoxia is where the delivery is fine, enough O2 through lungs picked up by
capillaries, however in the case of histotoxic hypoxia is when the oxygen that is in the tissues
can’t be utilized. like being all dressed up and no place to go
● oxygen is there, all set to do its job, but it doesn't happen. so the tissues become hypoxic,
not so much due to efficient oxygen, but because the oxygen cant be utilized
● the reason oxygen is so important (why is oxygen so necessary?) is because oxygen is the
ultimate electron and hydrogen acceptor at the end of the electron transport system
—————————————————————————————————
● oxygen is the ultimate electron and hydrogen acceptor at the end of the electron transport
system
● what happens is the glycolysis and kreb cycle, all feed materials into the electron transport
system, NAHD2s or whatever else, and as those electrons go down have oxidated
phosphorylation, the ADPs are phosphorylated to ATPs, and when those electrons travel
down the cascade they are picked up by oxygen along with their hydrogens and thats how
you get the water at the end of that equation
● so oxygen is necessary to accept, as long as you keep accepting and pulling those electrons
away the electron transport system continues to flow, if theres no oxygen it starts flowing, if it
doesn't flow then no ATPs can be produced
● most ATPs are produced from oxidated phosphorylation. its the oxygen
● in other organisms other atoms are used as the ultimate electron acceptor, not necessarily
oxygen, but for most aerobic organisms its oxygen
● histotoxic hypoxia is somehow the result of somehow the oxygen is there but not connecting
● when hemoglobin is in the ferric state, the oxidized state, the iron atom is oxidized, as soon
as this happens the hemoglobin is rendered negatory in its ability to pick up oxygen
● as it turns out, not only does hemoglobin have an iron atom, but also another enzyme of
great importance called cytochrome oxidase, and this is the enzyme that connects oxygen
with the electrons and the hydrogens to form water
● as it turns out, cytochrome oxidase also has an iron atom at its center, so if all of a sudden
you are exposed to cyinade, and the hemoglobin isn't picking up oxygen, whatever oxygen
you already have cant be functioning because the enzyme is destroyed
—————————————————————————————————
Asphyxia
***is a condition of O2 starvation that results whenever there is: A) low environmental O2 or a
failure/interruption in the delivery of O2 to the tissues OR B) failure in the utilization of O2 by the
tissues***
● so somewhere along the line when the oxygen is right at the tip of your nose or mouth, along
the way may be interruptions, breathing interruptions, clogged vessels, improper
hemoglobin, whatever
● another cause is even if oxygen gets to tissues, it doesn’t get utilized well by the tissues
***therefore asphyxia may occur from conditions in the lungs or the blood or the tissues***
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Have blood leaving the tissue, po2 is 40 (normal po2 is around 105) Partial pressure of oxygen is high, leaving the lungs and by the time it leaves the tissues its down to 40, not to 0, but 40. still some oxygen in your blood by the time it leaves. Oxygenation occurs in the capillaries, starts at 40, ends up at 105. leave, go to different blood vessels until finally you get to the tissues, internal respiration, arteriole taking you to the tissues. ***supplement 10*** (will go over much further later) So start with a tissue, and co2 leaves. Once co2 gets into plasma, have 2 options. 7% of co2 remains dissolved remainder of co2 goes into a red blood cella and only in the red blood cell is going to be responsible for most of the transportation of co2. ***the part of the respiratory pathway in which gas exchange does not take place*** this basically is the conducting zone.
