View Full Version : Biology Cardiac Output help!!
I get given these information:
http://img801.imageshack.us/img801/424/81695982.png
http://img651.imageshack.us/img651/7877/16102698.png
I got this to be 86 bpm.
http://img843.imageshack.us/img843/856/24382896.png
But When ever I do this I get it wrong to the Mark scheme.
I get the Stroke volume as 70 is that wrong?
Help please<3
mat
Mr[S]
01-08-2013, 09:53 PM
I'm guessing the info isn't on OP yet?
The Images are? They show up for me.
E: Changed Image Host.
CO = Stroke volume x Heart rate
and Stroke Volume is defined as
"Its value is obtained by subtracting end-systolic volume (ESV) from end-diastolic volume (EDV) for a given ventricle."
So, are you missing information? I dont see a way to calculate EDV and ESV?
Turpinator
01-09-2013, 01:49 PM
Now ive really got no idea how to do this, but if someone had thrown this at me with no knowledge of it whatsoever, id do this...
add up the volume of blood in each time frame (ie 0 to .1 and .1 to .2... etc) then multiply it by .1, which is the time the blood is in the ventricle or whatever. Ends up getting 65.6 cc. then id just multiply that by the 86 bpm to get 5633 cc/min
This is all done under the assumption that figure 1 is labeled incorrectly. Time/s should be written as Time (s) and volume of blood/ c^3 written as volume of blood (c^3). if you were to take time and divide by seconds... assuming time is measured in seconds here... you would just get a ratio. along with the volume. Some people may not have a problem with this 'notation' but i as a proper math notation 'stickler' would call my professor/teacher out on this for looking stupid. i would then proceed to do the entire problem 'wrong' just to get a 0 on it. From there id bring up the question in class and basically, subtly call my teacher a dumbass for making basic errors he/she should have learned/correct in middle school (possibly highschool).
Side note: cc = cubic centimeter = c^3
EDIT: On second look, i guess this makes more sense. we know that the lowest the volume of blood gets to is 55 cc, so instead of adding each volume, we will add each volume minus the baseline (55 cc)
so thats 70+93+48+15+1+0+43 = 270 ---> 270 * .1 = 27 cc or something.
multiply that by 86 bpm and you get 2322 cc/min
Final answer. 2322 cc/min
chongc
01-09-2013, 02:50 PM
you should put the answer so we can check with it :P
since you said you had the mark scheme :D
7905-7955 I think it ranged from
I'm assuming you got part b (i) by doing.. (1/(7/10))*60 = 85.714...
As for part b (ii).. (148-55)*85.714... = 7971.4 (rounding)
and (148-56)*85.714... = 7885.7 (rounding)
Then, (7971.4+7885.7)/2 = 7928.6 (rounding)
I'm assuming you got part b (i) by doing.. (1/(7/10))*60 = 85.714...
As for part b (ii).. (148-55)*85.714... = 7971.4 (rounding)
and (148-56)*85.714... = 7885.7 (rounding)
Then, (7971.4+7885.7)/2 = 7928.6 (rounding)
Just checked with my AP bio teacher, she confirmed what TehQ said was the correct answer.
chongc
01-10-2013, 04:09 PM
aha. i was like "148-56x86(someone said 86 bpm) == 7998)
but i have no idea how this stuff works, just that it appears to be off cuz of rounding.
Thanks for all helping :)
Mat
Thanks for all helping :)
Mat
NP :P Im willing to help with any bio, organic chem ect. Im going into medical (orthopedic surgeon) so Im always willing to learn if I dont know it!
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