# The Naked Scientists Forum

### Author Topic: How long does it take a red blood cell to complete a single lap of the body?  (Read 20012 times)

#### chris

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##### How long does it take a red blood cell to complete a single lap of the body?
« on: 08/09/2007 09:59:46 »
I am struggling to find some quality references and results for the average time taken by a red blood cell to return to the heart after completing one lap of the body. Can anyone help?

Chris

#### paul.fr

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##### How long does it take a red blood cell to complete a single lap of the body?
« Reply #1 on: 09/09/2007 13:32:57 »
Chris, i think you should ask Dave. According to this link (fact or fiction) http://www.thenakedscientists.com/HTML/podcasts/show/2004.12.12/ the time taken is 20 seconds.

This is backed up by Barbara McKinstry N.D. Doctor of Naturopathic Medicine when she states
"A red blood cell can circumnavigate your body in under 20 seconds. Nerve impulses travel at over 400 km/hr (250 mi/hr). A sneeze generates a wind of 166 km/hr (100 mi/hr), and a cough moves out at 100 km/hr (60 mi/hr)."
http://www.docbarb.com/docbarb_amazing.htm

the Kadlec Medical Center Bloodless Medicine & Surgery Program, also agree with 20 seconds.

#### eric l

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##### How long does it take a red blood cell to complete a single lap of the body?
« Reply #2 on: 10/09/2007 07:39:21 »
Is this to be seen as an average ?  A blood cell going from my heart to the tip of my nose and back will have less distance to cover than a cell going to the tip of my toe and back.  (Of course, it may well be that on the next lap that first cell goes to my toes or to my fingers).

#### chris

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##### How long does it take a red blood cell to complete a single lap of the body?
« Reply #3 on: 13/09/2007 11:40:24 »
Exactly Eric, that's the problem. It's really difficult to say. We know how long cells take to pass through different parts of the vasculature, but how this translates into the "average journey time" for a red cell I am unsure.

Chris

#### JimBob

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##### How long does it take a red blood cell to complete a single lap of the body?
« Reply #4 on: 14/09/2007 19:45:04 »
I guess it depends on which system of circulation is being discussed. Is it pulmonary system or the rest of the body?

#### iko

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##### How long does it take a red blood cell to complete a single lap of the body?
« Reply #5 on: 20/09/2007 12:16:50 »
I am struggling to find some quality references and results for the average time taken by a red blood cell to return to the heart after completing one lap of the body. Can anyone help?

Chris

Why such a theoretical issue is intriguing you so much?
Do you see any practical application in this issue?
It should go to...Cosmology!

iko
« Last Edit: 20/09/2007 17:10:45 by iko »

#### iko

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##### How long does it take a red blood cell to complete a single lap of the body?
« Reply #6 on: 21/09/2007 14:08:50 »
I guess it depends on which system of circulation is being discussed. Is it pulmonary system or the rest of the body?

Good point JimBob,

because the pulmonary circulation is certainly constant and supposedly easy to measure, but on the other side...Well, even accepting an average speed for blood flow, think of the different path and time from the left ventricle to the right atrium of a red cell going through a coronary artery, or up to the cerebral circulation or 'engulfing' the big filters like liver, spleen and the kidneys.   With such a difference of values, the average speed value should be useless indeed.
This wide difference explains why an injected substance is so efficiently mixed through the bloodstream.

ikod
« Last Edit: 21/09/2007 14:16:17 by iko »

#### The Naked Scientists Forum

##### How long does it take a red blood cell to complete a single lap of the body?
« Reply #6 on: 21/09/2007 14:08:50 »

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