Does the heart pumping and movement of blood affect body weight?

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Discussion Overview

The discussion revolves around the effects of heart pumping and blood movement on body weight, exploring theoretical implications and various perspectives on how these physiological processes might influence weight. The scope includes conceptual reasoning and theoretical physics, particularly in relation to momentum and energy.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants suggest that the heart pumping blood downwards would not change body weight, as any downward momentum is countered by an equal upward momentum.
  • Others propose that while the heart pumps blood, the overall effect on body weight remains zero due to equal and opposite reactions.
  • One participant introduces the idea that, according to relativity, the energy and pressure associated with blood movement could theoretically increase body weight, though this increase would be negligible and offset by energy expenditure.
  • There is mention of kinetic energy associated with rapidly moving blood, which raises questions about its potential effect on weight.
  • An analogy is made comparing the situation to compressing a spring, suggesting that potential energy could slightly increase weight, but this is contrasted with the energy consumed by the heart.
  • Assumptions are made regarding the volume of blood remaining constant, leading to a conclusion that there may be no net effect on weight from blood being pumped up or down.

Areas of Agreement / Disagreement

Participants express differing views on the relationship between heart pumping and body weight, with no consensus reached. Some agree on the principle of equal and opposite reactions, while others introduce relativistic effects that complicate the discussion.

Contextual Notes

Unresolved assumptions include the impact of kinetic energy on weight and the practical measurability of any changes in weight due to blood movement. The discussion also touches on gravitational differences in various body regions, which may influence interpretations.

ATPenergy
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When the heart pump and blood flow down the body , Does the body wieght increase,be the same or decrease? Why?
 
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It is not possible for the heart to pump blood downwards without pumping an exactly equal amount upwards.
 
Ok. Let's pump blood upwards also
 
Well, since the momentum of the blood being pumped downwards is necessarily identical in magnitude to the momentum of the blood being pumped in the opposite direction, then net effect is zero and therefor your weight remains the same.
 
Does the body has momentum upwards?
 
Equal and opposite reactions. Like birds flying in the back of a mach truck. It makes no difference, the weight remains constant.
 
EXACTLY what negitron said!
 
According to relativity, pressure,energy and mass all have a gravitational effect...So body weight would increase as the heart pumps but not enough for us to actually measure... In practice any such gain would be more than offset by the calories consumed pumping...
Rapidly moving blood also has kinetic energy; not so easy a question to answer but I'm pretty sure the next effect is a loss in "weight".

By analogy, compressing a spring means it has potential energy stored...hence it's weight increases just a tiny,tiny,bit...in that case the energy is clearly added to the system unlike the example with a heart burning calories(energy).

Assuming the volume of blood does not change there is no net effect of blood being pumped up or down...this could be of interest since gravity at the head is less than at the feet.
 
  • #10
Naty1 said:
According to relativity, pressure,energy and mass all have a gravitational effect...So body weight would increase as the heart pumps but not enough for us to actually measure... In practice any such gain would be more than offset by the calories consumed pumping...
Rapidly moving blood also has kinetic energy; not so easy a question to answer but I'm pretty sure the next effect is a loss in "weight".

By analogy, compressing a spring means it has potential energy stored...hence it's weight increases just a tiny,tiny,bit...in that case the energy is clearly added to the system unlike the example with a heart burning calories(energy).

Assuming the volume of blood does not change there is no net effect of blood being pumped up or down...this could be of interest since gravity at the head is less than at the feet.


Probably not the answer the OP was looking for...
 

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