Majed Sharayha
Posts : 130 Reputation : 5 Join date : 2011-08-23 Age : 31
| Subject: Physiology, Sheet 7, Dr.yanal 1422012 Fri Feb 17, 2012 5:26 am | |
| Download link----------------------------> Click here-------------------------------------------- In newborn of children: In the case of IRDS (infant respiratory distree syndrom) For adult this stste is called ARDS (A:not adult but it is an acute respiratory distree syndrome) We knew previously from the last lecture that the IRDS is case causing high surface tension so the main effect the lung tends to be collapsable In conclusion RDS maybe occure in : 1- adults 2- children DRS : breathing failure + respiratory failure + inflattant failure “ heart failure” When th O2 going to diffuse from alveoli to the capillary “ blood “ then the Po2 is equal 100 mmhg in the alveoli and in the blood the Po2 is equal 40 mmHG NOW , the blood is going to pulmonary capillary is equal to the cardiac cycle = 0.8 sec If the cardiac cycle is 0.8 then the pulmonary cycle reach also 0.8 sec Not only needing 0.8 sec to complete exchange so we have plenty of time when u do exercise the cardiac cycle shrenk to 0.5 sec , so ur in the save side so there z enough time to exchange . NOW the Q is : how much o2 can diffuse from alveoli to blood per min for each 1 mmHG ?!! => the pressure difference between the alveoli and the blood is 1 mmHG How much o2 can be diffused >> this is called difusing capacity of the lung for o2 (DLo2) DIFFUSION CAPASITY OF THE LUNG of o2 >> FOR 1 mmHG in the alveoli E.x : when the pressure difference is equal 10 mmhg >> Then the o2 fissusion is equal of o2 SO >>> 10 MMhg ----- 500 ml of o2 1 mmhg ------> ??? SO The o2 diffusion capacity per 1 mmhg = 50 ml o2 If we consider the pressure difference between the blood and alveoli is 10 mmhg , and the o2 which is diffuses is equal 500 ml o2 Complete oxygenation is equal 100 mmhg If we divide the diffusion of o2 from alveoli to capillary to 2 parts : First one third complete oxygenation The second two third is no more diffusion of oxygen SO itz very difficult to measure the pressure difference of o2 and diffusion =>> so at the beginning the Po2 = 100-40 = 60 At the first one third = 0 At the middle third = 30 mmhg It’s very complicated , how much is Po2 cross the entire capillary We can’t measure the diffusion capacity for the o2 coz we can’t measure the pressure difference between the 2 compartment for some reason we use the diffusion lung capacity for CO , when the person is breathing little CO then we measure , how much is CO is diffusing . If u know the diffusion coefficient solubility of “ CO” & “ CO2 “ & “O2”
S CO ---- 0.8 * s >> solubility S CO2 --- 20 S O2 --- 1 If the diffusion capacity of the lung for CO2 is 17 ml/ min for each 1mmhg So , DL CO = 17/1 = 17 ml/min DL o2 = 21 ml DL co2 = 400 ml We measure diffusion capacity for “ CO2 & O2 “ through “ CO “ , BUT THE PRESSURE difference of O2 is difficult to be determined . but , u can determine the pressure difference for CO2 “ FOR SOME REASONS “ WE talked previously about : The O2 and CO2 distribution inside and outside the lung We talked about the air ways resistance The compliance and the diffusion across this wall The “ O2 + CO 2” : IS NOT diffusion limited , its perfusion limited If u need more o2 >>>> this will make more blood available “ making cardiac out put >> not 5 liters but 10 liters “ The lung usually can provide o2 if u have enough blood in the capillary it’s from blood in the pulmonary capillary “ the availability of blood “ It’s not like diffusion capacity or capability from the lung Now if we go to the blood : >>we have around 7% at body weight is blood &its around 5 litre 5 litre =5000 ml 5000 ml=5*10^6 micro litre For each 1 micro litre >>5*10^6 RBC In 1 RBC>>280*10^6 HB The HB : Blood is consist from : 1- 55% plasma 2-45% from element(mainly RBC) Plasma is consist from: 1-90% water 2-8% other mainly albumin WBC >> 1/1000 from RBC(In 1000 RBC>> 1 WBC) Amount +no. of WBC =5000WBC / micro litre The no. of RBC = 5*10^6 RBC / micro litre The hemoglobin concentration =(15 gm/dl) For 100 ml>> 15 gm /dl The O2 isfirstly go from alveoli to the plasma >>plasma if it is attached (attracted )to the water (water-O2)compound ,so the solubility is high >>if the water hate the oxygen then the solubility become low If the solubility is low ; when you add O2 then the partial pressure of O2 is starting to rise (it would be relatively high ) If the solubility is high >you add O2 (H2O attracts O2 ) its cleaned by water (attracted to the water),that more O2 without increasing in the PO2 ,you add O2 without increasing in PO2 The partial pressure of O2 in the plasma , if its become 100 MMHG ,same as alveoli ,there is no O2 can diffuse anymore from alveoli is the plasma . >>now we know that the solubility of O2is low & the solubility of CO2 is high EX : in (cocacola)>> I can not put O2gas due to bad solubility,but I can put CO2 gas due to its high solubility >>I can put more of CO2 The partial pressure of O2in the plasma is =PO2 in the alveoi The prople is PO2(plasma)=100MMHG According to the henry law , the concentration of O2 in the water depend on: 1-partial pressure of oxygen in the solution (water) 2-the solubility of the gas in the solution (H2O) So , henry law =PO2 * solubility (S decrease >>>PO2 increase)in the plasma The solubility of O2 in plasma =.003 PO2 =100 MMHG SO the conc. Of O2 in the plasma =100*.003 =.3 ml/dl O2 (for each 100 ml blood>>H is going to carry .3 O2 IN dissolve form in plasma) Now we got .3 ml O2 in plasma Actually our cells >>how much O2 are they extracted?? Now if we look to this diagram
The cell is going to extract the O2 carried by the arterial blood that delivered to the capillary The amount of O2 that carried by the blood is =(2 ml of O2/dl blood) Now >>O2 that is carried by the blood =2 PO2 inarterial side =100 mmhg >>100ml blood( arterial )>>20 ml O2/dl blood >>that how much the blood is delivered to the capillary The cell extract 25% of O2 from arterial blood =5 ml >>(5/20)*100%=25% Leaving the (15 ml/75%): the venous to the right side (venous) In the plasma , the conc. Of O2 .3 ml /dl in plasma >> because it is water (90%)>>concentration of O2=.3 ;so the plasma its very weak (bad)carrier of O2 (not carrying O2) I need 5 litre >>but there is .3 litre &20 ml/dl from arterial
THE HEART : How much is ejecting per DL ?? the heart eject 50 ml /DL e From each one ml / dl the cell extract 5 ml >> the extracted volume of O2 from 20 ml / dl = 50 ml / dl >> so the total oxygen consumption by our body / min is equal 5*50 = 250 ml "at rest" The O2 consumption v'o2 = 250 ml In the next lec we are going to know the CO2 production / min NOW the O2 consumption during exercise : when u do exercise the O2 consumption increasing If u do more exercise the O2 consumption is reaching to the maximum consumption of O2 V'O2 max " platue phase " But am not going to get any thing from the plasma ……!!! The blood form one half of the plasma " 50 %" this is called " hematocrite pcv " Hb >> cons of hemoglobin = 15 gram / dl For male = 14 – 16 ml / dl For female = 13 – 15 ml / dl Avg = 15 ml/dl for male Now one gram of hb bind with with 1.34 O2 ml 15 gram of hb ???? Soooooo : 15 gram of hb bind to 19.5 O2 ml
>> 1 dl of blood contains 0.3 ml of O2 " in the dissolved form " >> 19.5 ml of O2 " in the binding form "
19 .8 = 20 ml / dl of O2 20% >> cons of O2 in the blood 3 % dissolved as 0.3 in the plasma >>>>>>> 97 % binding to the hb Hb : has 2 alpha subunit " 1 alpha has 141 amino acid " : 2 beta subunit " 1 beta subunit has 146 amino acid " Molecular weight of hb = 64.500 or less than 70.000 " 70 k" Hb has 4 chain : 2 chains larger than 2 other chains In each of them > one heme > this heme has an iron oand O2 bind to this iron in the ferrous state not in the ferric state " oxygenated hb " 1 hb >>> can bind from "1-4" O2 molecule but the hb has NH2 group & COOH group sooooo the hb binding with o2 is determind by the o2 availability & its conciderd as 100 % & this is determind by partial pressure , more partial pressure > the more availability of O2 , so more chances of the hb to bind the O2 From 1 : u need to supply much o2 > to force binding O2 to hb " as there is asalt – bridge in hb "
From 2 : any additional O2 in this stage > then there is will be high affenty to binding O2 with hb " steep line "
From 3 : the hb is saturated with o2 from 90 – 100 % this is always in the lung "opposite to arterial one "
Now we r starting to talk about the specific realation ship between O2 and hb , and this relation ship is sigmoidal Hb in the RBC >> how much O2 is going to bind with hb " atmospheric O2 is surrounded by this blood in another why the the plasma surround the RBC contains O2 ?! If I take the arterial side of capillary the PO2 artrial = 100 PO2 venous = 40 bthr At beginning of capillary PO2 = 40 at the end of capillary PO2= 100 >>>> how much o2 is binding to hb in the lung ?!! When the PO2 a = 100 , when the po2 = 100 then the situation of binding o2 with hb > is high affinity 98 % This mean if I put mask in the enter of nasal cavity and this mask not contain air room and u caliprates this mask to give the patient 100% o2 Soooo this means the amount of o2 who is taken it =760atm(O2 only) No (N2,co2) >>>>in astate when the po2 is added more than 100% ,,how much O2 is added to hb ??? None "there is no any o2 is added to the hb " U are only adding to the plasma "notice that ,the plasma o2 conc . was 0.3 ml/dl " Now almost of o2 is added to plasma is equal : 600*0.003=1.8ml/dl o2 (increase po2,decrease S" (it is not enough because we need 5L to supply the cell
>>>under high pressre in the plasma >there is providing of free radicals >Sooo O2 poisining occure. And you might cause too much hard to the person //patient what ever ,if u allowing for providing pure o2 for along time >>this causing o2 poisining >and we don’t like
In new born : increasing the "P" of O2 in the plasma causing irreversible blindness
During ventilation >>providing much o2 >>killing the patient
RDS: State:put the patient in the incubate CPAP "continuous positive airway pressure" "first method" PEEP: State:put intubation"pyt tube"in the trachea"positive in expiratory pressure">>ventelation >>to relax the muscles of patient "machine works instead of this patient expairation >>>if we provide the patient much more O2 >the patient will become suffering from Fibrosis in the eye "this Fibrosis is irreversible>causing perment blindness" COPD: IN adult( who he has COPD) ABGs like COPD:arterial blood gases >>decrease the PO2 ,increase PCO2 Note"EX. Chronic bronchitis, emphsyma" >>>if I supply aperson ,he can not take breathing very well in more amount of O2>>this O2 will kill him immediately (by this O2,you suppressed the respiratory centre Control of breathing : ?????we can not get pure O2 to COPD ,why??what is the risk from this state ?? HB >>>it is function to carry O2 which type of HB you binding ,,would uou like HB to love O2 or to hate O2 ???? >>in the lung ,we love HB to bind O2 (love it) >>in the tissue "cell" , we love HB to leave O2 (hate it).
GOOD LUCK JUMANA AL-ZO3BE & ISLAM AL-DAGAG THANX 4 EMAN AL-SHAWAWREH | |
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