Results 1 to 12 of 12

Thread: Biology Cardiac Output help!!

  1. #1
    Join Date
    Nov 2011
    Posts
    1,589
    Mentioned
    9 Post(s)
    Quoted
    17 Post(s)

    Default Biology Cardiac Output help!!

    I get given these information:




    I got this to be 86 bpm.



    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



    ^^

  2. #2
    Join Date
    Jul 2012
    Location
    London
    Posts
    1,549
    Mentioned
    0 Post(s)
    Quoted
    86 Post(s)

    Default

    I'm guessing the info isn't on OP yet?

  3. #3
    Join Date
    Nov 2011
    Posts
    1,589
    Mentioned
    9 Post(s)
    Quoted
    17 Post(s)

    Default

    The Images are? They show up for me.
    E: Changed Image Host.



    ^^

  4. #4
    Join Date
    Jun 2012
    Location
    Howell, Michigan
    Posts
    1,585
    Mentioned
    34 Post(s)
    Quoted
    553 Post(s)

    Default

    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?

  5. #5
    Join Date
    Jan 2012
    Posts
    1,596
    Mentioned
    78 Post(s)
    Quoted
    826 Post(s)

    Default

    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
    Last edited by Turpinator; 01-09-2013 at 01:53 PM. Reason: second thoughts

  6. #6
    Join Date
    Aug 2010
    Posts
    213
    Mentioned
    0 Post(s)
    Quoted
    34 Post(s)

    Default

    you should put the answer so we can check with it :P

    since you said you had the mark scheme
    <--Previously known as fiery oblivion-->

  7. #7
    Join Date
    Nov 2011
    Posts
    1,589
    Mentioned
    9 Post(s)
    Quoted
    17 Post(s)

    Default

    7905-7955 I think it ranged from



    ^^

  8. #8
    Join Date
    Nov 2011
    Location
    MA
    Posts
    545
    Mentioned
    3 Post(s)
    Quoted
    10 Post(s)

    Default

    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)
    Last edited by tehq; 01-09-2013 at 05:04 PM.

  9. #9
    Join Date
    Jun 2012
    Location
    Howell, Michigan
    Posts
    1,585
    Mentioned
    34 Post(s)
    Quoted
    553 Post(s)

    Default

    Quote Originally Posted by tehq View Post
    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.

  10. #10
    Join Date
    Aug 2010
    Posts
    213
    Mentioned
    0 Post(s)
    Quoted
    34 Post(s)

    Default

    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.
    <--Previously known as fiery oblivion-->

  11. #11
    Join Date
    Nov 2011
    Posts
    1,589
    Mentioned
    9 Post(s)
    Quoted
    17 Post(s)

    Default

    Thanks for all helping
    Mat



    ^^

  12. #12
    Join Date
    Jun 2012
    Location
    Howell, Michigan
    Posts
    1,585
    Mentioned
    34 Post(s)
    Quoted
    553 Post(s)

    Default

    Quote Originally Posted by Mat View Post
    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!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •