1. The SDN iPhone App is back and free through November! Get it today and please post a review on the App Store!
    Dismiss Notice
  2. Dismiss Notice
  3. Guest, be sure to check out How To Get Into Dental School, our free downloadable PDF with step-by-step details for dental school applicants!
    Dismiss Notice
  4. Dismiss Notice
Dismiss Notice

Interview Feedback: Visit Interview Feedback to view and submit interview information.

Interviewing Masterclass: Free masterclass on interviewing from SDN and Medical College of Georgia

Blood Pressure question

Discussion in 'DAT Discussions' started by ard14, Jul 16, 2006.

  1. ard14

    ard14 Junior Member
    2+ Year Member

    Joined:
    Jun 1, 2006
    Messages:
    26
    Likes Received:
    0
    Status:
    Pre-Dental
    Question 29 of Kaplan's online diagnostic test states the blood pressure drops for two reasons: increased cross-sectional area, which makes sense, and increased friction in blood vessel walls, which does not make sense to me. Why would increasing friction decrease blood pressure, shouldn't it do the opposite, increase BP, as is the case with arteriosclerosis?

    Thanks
     
  2. Note: SDN Members do not see this ad.

  3. vize

    vize Member
    2+ Year Member

    Joined:
    May 8, 2006
    Messages:
    210
    Likes Received:
    0
    Status:
    Dental Student
    i'm not sure arteriosclerosis causes high blood pressure, rather, high blood pressure may cause arteriosclerosis. i think friction decreases blood pressure because it's going to make it harder for the blood to flow as fast
     
  4. tinman831

    tinman831 ¯\_(ツ)_/¯
    Administrator Dentist Lifetime Donor Classifieds Approved 10+ Year Member

    Joined:
    Dec 11, 2004
    Messages:
    11,348
    Likes Received:
    73
    Status:
    Dentist
    An increase in resistance or friction would cause an increase in blood pressure.
     
  5. artmed12

    artmed12 Member
    5+ Year Member

    Joined:
    Apr 3, 2005
    Messages:
    61
    Likes Received:
    0
    Hi,
    a decrease in the velocity of blood will result in a decrease in blood pressure. The question is not asking the reasons blood pressure drops, but the mechanism for the drop:

    1. the increase in cross sectional area is referring to when an artery branches into an arteriole then finally the capillaries, imagine a river flowing into many more little rivers, this decreases blood pressure because there is more total area (the many capillaries vs. 1 artery)

    2. the increase in friction is due to millions of blood cells flowing through an artery having an abrupt halt when the blood hits the one-celled thick diameter of the microscopic capillaries, this halts the velocity of blood, hence lowers blood pressure.

    these are two ways to reduce that blood pressure drops in the body, not the reasons FOR blood pressure drop, you merely misread the question.
     
  6. artmed12

    artmed12 Member
    5+ Year Member

    Joined:
    Apr 3, 2005
    Messages:
    61
    Likes Received:
    0
    1 more thing:

    you guys are right that an increase in the friction due to arteriosclerosis will increase b.p. because it shrinks the diameter of the artery

    but, the friction that was referred to in the question was the friction that slows blood when it gets forced from an arteriole to a thin capillary. the blood pressure drops when it goes through the capillary at a slow rate.
     

Share This Page