1. Dismiss Notice
  2. Download free Tapatalk for iPhone or Tapatalk for Android for your phone and follow the SDN forums with push notifications.
    Dismiss Notice
Dismiss Notice
Visit Interview Feedback to view and submit interview information.

Effects of Hormones on BP

Discussion in 'MCAT Study Question Q&A' started by justadream, Sep 5, 2014.

  1. justadream

    7+ Year Member

    Joined:
    Apr 29, 2011
    Messages:
    2,173
    Likes Received:
    810
    Would:

    Glucagon = increase pressure (more glucose in blood - draws more water into blood vessels)
    Insulin = decrease pressure (less glucose in blood - draws water into tissue)

    Also, what about things that increase metabolic rate?

    Epinephrine = increase pressure (more glucose in blood - draws more water into blood vessels)
    Thyroxine = increase pressure (more glucose in blood - draws more water into blood vessels)
     
  2. Note: SDN Members do not see this ad.

  3. Czarcasm

    Czarcasm Hakuna matata, no worries.
    5+ Year Member

    Joined:
    Jun 22, 2013
    Messages:
    966
    Likes Received:
    407
    Status:
    Medical Student (Accepted)
    Nearly 100% of glucose is reabsorbed by the nephron in the kidney, along with other essential nutrients. Neither insulin or glucagon would influence blood pressure in any significant way. Blood pressure is effected by a variety of factors (resistance of blood flow by vasoconstriction, heart rate, fluid retention, temperature, etc).

    Epinephrine is released during the sympathetic response (which as a consequence of the collective SNS response, increases blood pressure). Throxine increases metabolic activity of the body, so you might say it would increase pressure. I would focus on the primary actions of these hormones, what stimulates their release, and what happens when they are released in excess, etc. I understand you're trying to think outside the box, but there's no need to involve blood pressure here.
     
  4. justadream

    7+ Year Member

    Joined:
    Apr 29, 2011
    Messages:
    2,173
    Likes Received:
    810
    @Czarcasm

    I get that glucose is reabsorbed by the kidney but why does that change anything?

    If glucagon increases glucose levels in the blood, the kidney will simply take some of it in and put it all back into the blood. So at the end of the day, glucose remains in the blood. Why wouldn't this affect blood pressure?
     
  5. Czarcasm

    Czarcasm Hakuna matata, no worries.
    5+ Year Member

    Joined:
    Jun 22, 2013
    Messages:
    966
    Likes Received:
    407
    Status:
    Medical Student (Accepted)
    I'm assuming here, your basing your reasoning on blood osmolarity - that is increasing or decreasing blood osmolarity (through glucose) would alter blood pressure. What I was trying to get at is that glucose levels in the blood are maintained at a relatively constant level in most people through the hormones insulin and glucagon. Perhaps briefly after a meal when glucose levels are high, you might predict that blood pressure may rise, but the action of insulin in almost instantaneous. High blood glucose triggers insulin release and almost immediately as it enters the blood, insulin repackages excess glucose for storage as glycogen in the liver and skeleton. At the same time, excess loss is prevented by complete reabsorption in the kidney. For this reason, it's highly improbable to assume that blood glucose would alter blood pressure to any significant degree, atleast for a healthy, non-diabetic individual. On the other hand, certain solutes like salt can and will increase blood pressure. We have no way of packaging excess salt. It just remains in the blood. The only way to remove excess salt in the blood is through excretion in the kidney. The hormone ANP released by the heart in response to high blood pressure allows for this excretion to happen, in order to reduce blood pressure to a healthy range. The problem with sodium and the reason it causes high blood pressure is that it increases the osmolarity of the blood. Osmoreceptors in the hypothalamus recognizes this change in blood osmolarity and releases ADH, which acts on the nephron of the kidney to increase water retention. Ultimately, it's this water retention that causes the high blood pressure.
     
    Cawolf likes this.

Share This Page