Thread Tools
Old 01-15-2004, 02:16 PM
Guest
Join Date: Jan 2004
Posts: 5
How fast does blood travel through the body?

I've read that we have approximately 60,000 miles of blood vessels in our bodies, that a 155 pound person has 11 pints of blood and that blood travels through the lungs at the rate of once per minute. I realize that individual blood pressure varies and will affect the rate, but that makes it look as though our blood goes 60,000 miles a minute! Wouldn't we just explode? Obviously the math must be a lot more complicated than I'm making it.
Old 01-15-2004, 02:39 PM
vd vd is offline
Guest
Join Date: Jun 2000
Posts: 578
That high speed would be true if your blood had to go around one continuous loop.

But an individual blood cell that ends up in your big toe before coming back doesn't have to go everywhere else in your body before or after. If I used that technique commuting to work, I would have to zig-zag over every stretch of road in the city every day. Yes, I would have to go very fast for that.

And welcome to the SDMB!
Old 01-15-2004, 02:48 PM
Guest
Join Date: Jan 2004
Posts: 5
Thanks. But, really, how fast does it travel? Does the velocity of blood through the circulatory system vary, depending on where it's going?
Old 01-15-2004, 03:05 PM
Member
Join Date: Jun 2001
Location: in a Moot
Posts: 11,621
agrecian - No, the velocity of a blood is different in different parts of your body. Not by much, but it is different. It depends on things like viscosity and pressure. For instance, blood entering your heart is doing so through large arteries. Therefore the volume is such that it is going quite fast. However, in the small capilaries located in your nose, there is but a fraction the volume that there would be in an vein or artery, and the blood is traveling slightly slower...it's not very marked. Check this cite
__________________
“You are lead through your lifetime by the inner learning creature, the playful spiritual being that is your real self. Don’t turn away from possible futures before you’re certain you don’t have anything to learn from them. You are always free to change your mind and choose a different future, or a different past.”
Old 01-15-2004, 03:12 PM
vd vd is offline
Guest
Join Date: Jun 2000
Posts: 578
This gives a rough order-of-magnitude estimate of 425 cm/s (around 9.5 mph).

This pdf puts the peak velocity at the aorta at 80-130 cm/s. (I guess their mileage did vary)

My guess: the velocity will go up and down during the beat but the stretchiness of your veins will make that even out the farther it is from the heart.
Old 01-15-2004, 03:27 PM
BANNED
Join Date: Mar 1999
Posts: 1,093
The speed varies at different points of the body due to lots of factors.
If the flow were unimpeded, the same volume of blood would travel per second, causing narrower veins to carry blood at higher rates of speed.
Like squeezing a garden hose makes a thinner stream squirt farther.
But, there's the counter effect of arterial branching, so the cross secional area of all branches must be considered together.
However, friction becomes the dominate factor at some point, so by the time you reach the capilaries the original pulse is lost and flow is steady.
Old 01-15-2004, 03:58 PM
Guest
Join Date: Nov 2002
Location: sNUgGLYPUPpY [censored]
Posts: 2,148
Clearly the speed varies based on where it's flowing and how much branching is happening. But I'm just curious about rough estimates about how long it takes blood in my heart to reach, say, my wrist (basically, traveling down large trunks, avoiding the issue of getting into all the nooks and crannies).
Old 01-16-2004, 09:38 AM
Guest
Join Date: Jan 2004
Posts: 5
I'm curious about that, too. Is there a way to measure that?
Old 01-16-2004, 11:52 AM
Guest
Join Date: Oct 2002
Location: Wisconsin, Untied States
Posts: 7,276
Sure it can be measured.

Some sort of die can be injected into a vein and then tracked with imaging equipment. (MRI, CAT scan, etc.)

Or you could ask a crack-head how long it takes the high to go from his lungs, through the heart, and then to the brain. Probably just seconds, then calculate the distance and divide by time.
__________________
No signature.
Old 01-26-2004, 06:10 AM
Guest
Join Date: Jan 2004
Posts: 5
I can't believe no one can answer this. I really thought this would be an easy one.
Old 01-27-2004, 01:59 PM
Guest
Join Date: Jan 2004
Posts: 5
Whew! Found it, I think. Apparently, blood moves at the rate of about 1 mph, leaving the heart, but of course slows down as it heads into the home stretch back to the heart. So pretty slowly, although at the size of a blood cell that's probably relatively fast. Here's the link, if anyone else was curious about this:
http://earthlife.net/mammals/blood.html
Thanks, everyone, for your help.
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 09:29 PM.

Copyright © 2017
Best Topics: old encyclopedias sustained orgasm hospital toilets injection air godaddy redemption period accepting mediocrity fucking leaf bo dietl goodfellas jane wymark young sexy american accent surnames van square rig santa flush gov't cheese cryptogram decoder seabees tattoo hotel caretaker hbo softcore porn kambo wiki bananagrams vs scrabble scrotal cysts removal apache 30mm pizza with ketchup drinking pure alcohol generator enclosure diy swimming in boxers youtube boogers legal anywhere wrs bacon number enigma wrapped drowning process how to delete a placeholder entry in quicken cute flower shop names how often do gay couples have intercourse sandra bernhard jay leno smoke detectors keep going off for no reason guns used in the good the bad and the ugly white singers who sound black trailer sways side to side where can i buy a dolphin what happens if you eat coffee grounds why does cracking back relieve pain how to make permanent hair dye fade why do vultures circle does decaf tea taste different my flag boy and your flag boy sitting by the fire lyrics difference between british and australian accents who makes great value potato chips officemax vs office depot boil smells like cheese how big is a 6 quart slow cooker girl bike vs boy bike what else can you pop besides popcorn see you later alligator in a while crocodile how to pronounce chaim removing nicotine stains from painted walls spanked with a paddle motor-driven cycles how to sharpen serrated steak knives oil light comes on when idle kb national research complaints how long is 7 inches clear care vs opti free mutants and masterminds combat why do tetnis shots hurt ellen without makeup mediatakeout