Fastest parts of human body

[Kevin Stone]

Hi,

I was pondering what parts of the human body are the fastest moving? Let's
get a nice sequenced list with some speed estimates:

o Nerve signal (not a part of the body, but could be the quickest)
o Eyelid during blink
o Fingers whilst being clicked
o Parts of the respiratory tract whilst sneezing/coughing
o Tips of fingers during some types of activity

Fastest voluntary muscle?

Not a very big list yet, but it's very early...

[Brian Tung]

Post by Kevin Stone
I was pondering what parts of the human body are the fastest moving? Let's
o Nerve signal (not a part of the body, but could be the quickest)

Don't have a citation, but I remember reading that this travels on the
order of meters to tens of meters per second, depending on the signal.

Post by Kevin Stone
o Eyelid during blink

I'd be surprised if this was more than a meter per second.

Post by Kevin Stone
o Fingers whilst being clicked

Clicked? Maybe snapped? Probably meters per second.

Post by Kevin Stone
o Parts of the respiratory tract whilst sneezing/coughing

Apparently, sneeze droplets escape the mouth at maybe 50 meters per
second.

Post by Kevin Stone
o Tips of fingers during some types of activity

By combining the various motions of the body cooperatively, the tips of
fingers of talented pitchers can release a baseball, relative to the
ground, at almost 50 meters per second.

Post by Kevin Stone
Fastest voluntary muscle?

Relative to what?

[Kevin Stone]

Post by Brian Tung

Post by Kevin Stone
o Fingers whilst being clicked

Clicked? Maybe snapped? Probably meters per second.

Snapped and clicked are interchangeable in the UK, but I chose clicked as
snapped may be interpreted as broken forcibly.

[Kevin Stone]

Post by Brian Tung

Post by Kevin Stone
Fastest voluntary muscle?

Relative to what?

Relative to rest?

:)

[Brian Tung]

Post by Kevin Stone

Post by Brian Tung

Post by Kevin Stone
Fastest voluntary muscle?

Relative to what?

Relative to rest?

What I mean is, relative to the ground (whatever the person is resting
on), or relative to the attachment point(s) of the muscle?

[[Jongware]]

Post by Brian Tung

Post by Kevin Stone

Post by Brian Tung

Post by Kevin Stone
Fastest voluntary muscle?

Relative to what?

Relative to rest?

What I mean is, relative to the ground (whatever the person is resting
on), or relative to the attachment point(s) of the muscle?

Depending on your POV, the fastest body part would be the ones plummeting
down a ravine ;-)

[Jw]

[Kevin Stone]

Post by Kevin Stone
Fastest voluntary muscle?

What I mean is, relative to the ground or relative to the attachment
point(s)

Whichever gives you the fastest speed.

[Brian Tung]

Post by Kevin Stone

What I mean is, relative to the ground or relative to the attachment
point(s)

Whichever gives you the fastest speed.

Then my guess is probably a pitcher's fingertips as he releases the
baseball (relative to the ground he's standing on). There are certainly
body parts that move faster than that, but not voluntary muscles, I
don't think.

[George Weinberg]

Post by Brian Tung

Post by Kevin Stone

What I mean is, relative to the ground or relative to the attachment
point(s)

Whichever gives you the fastest speed.

Then my guess is probably a pitcher's fingertips as he releases the
baseball (relative to the ground he's standing on). There are certainly
body parts that move faster than that, but not voluntary muscles, I
don't think.

Well, the pitcher ought to be able to whip his hand faster if he isn't
throwing a baseball, but moves as if he were, since the mass of the
baseball would slow him down.

George

[Rich Grise]

Post by George Weinberg

Post by Brian Tung

Post by Kevin Stone

What I mean is, relative to the ground or relative to the attachment
point(s)

Whichever gives you the fastest speed.

Then my guess is probably a pitcher's fingertips as he releases the
baseball (relative to the ground he's standing on). There are certainly
body parts that move faster than that, but not voluntary muscles, I
don't think.

Well, the pitcher ought to be able to whip his hand faster if he isn't
throwing a baseball, but moves as if he were, since the mass of the
baseball would slow him down.

I'd think the opposite would be true. The ball may slow down the
_acceleration_ of his hand from point A to point B, but I'd think that
at the release point of the arc, the mass of the ball would actually
contribute to the crack-the-whip effect.

Thanks,
Rich

[Rich Grise]

Post by Brian Tung

Post by Kevin Stone
Fastest voluntary muscle?

Relative to what?

The rest of the voluntary muscles? Although, I'd seriously doubt
if any muscle could jerk as fast as the movement you'd get by
restraining a limb, and suddlenly releasing it. (like snapping/
clicking the fingers).

And, isn't that clicking sound caused by your finger breaking
the sound barrier? ;-) ;-) ;-)

Cheers!
Rich

[Bull]

Post by Kevin Stone
Hi,
I was pondering what parts of the human body are the fastest moving? Let's
o Nerve signal (not a part of the body, but could be the quickest)
o Eyelid during blink
o Fingers whilst being clicked
o Parts of the respiratory tract whilst sneezing/coughing
o Tips of fingers during some types of activity
Fastest voluntary muscle?
Not a very big list yet, but it's very early...

Vocal cords?
Ear "hammer"?
Curry sphincter?

[Rich Grise]

Post by Bull

Post by Kevin Stone
I was pondering what parts of the human body are the fastest moving? Let's
o Nerve signal (not a part of the body, but could be the quickest)
o Eyelid during blink
o Fingers whilst being clicked
o Parts of the respiratory tract whilst sneezing/coughing
o Tips of fingers during some types of activity
Fastest voluntary muscle?
Not a very big list yet, but it's very early...

Vocal cords?
Ear "hammer"?

That's a bone. :-/

Post by Bull
Curry sphincter?

I don't even know what this means.

Cheers!
Rich

[JimS]

On Wed, 23 May 2007 09:03:19 +0100, "Kevin Stone"

Post by Kevin Stone
Hi,
I was pondering what parts of the human body are the fastest moving? Let's
o Nerve signal (not a part of the body, but could be the quickest)
o Eyelid during blink
o Fingers whilst being clicked
o Parts of the respiratory tract whilst sneezing/coughing
o Tips of fingers during some types of activity
Fastest voluntary muscle?
Not a very big list yet, but it's very early...

Pupil contraction?

Jim

[Carl G.]

Post by Kevin Stone
Hi,
I was pondering what parts of the human body are the fastest moving? Let's
o Nerve signal (not a part of the body, but could be the quickest)
o Eyelid during blink
o Fingers whilst being clicked
o Parts of the respiratory tract whilst sneezing/coughing
o Tips of fingers during some types of activity
Fastest voluntary muscle?
Not a very big list yet, but it's very early...
--
Kev

What is your definition of "part". The smaller "parts" usually have faster
speeds. Are parts of parts parts? Are photons a part of the human body?
Electrons also move fairly fast. Electrons are parts of atoms, atoms are
parts of molecules, molecules are parts of mitochondria, mitochondria are
parts of cells, cells are parts of organs, and organs are parts of the human
body. So, are parts of parts that are parts of parts that are parts of
parts that are parts of parts that are parts of parts, parts?

Carl G.

[Rich Grise]

Post by Carl G.

Post by Kevin Stone
I was pondering what parts of the human body are the fastest moving? Let's
o Nerve signal (not a part of the body, but could be the quickest)
o Eyelid during blink
o Fingers whilst being clicked
o Parts of the respiratory tract whilst sneezing/coughing
o Tips of fingers during some types of activity
Fastest voluntary muscle?
Not a very big list yet, but it's very early...

What is your definition of "part". The smaller "parts" usually have faster
speeds. Are parts of parts parts? Are photons a part of the human body?
Electrons also move fairly fast.

Are you talking about their orbital speed in the Bohr model? If you're
talking about current, the charge moves at C * V, but the electrons move
a few inches an hour. (V = velocity factor, a number less than 1, that
depends on the medium)

Nerve impulses seem to be fairly quick.

Post by Carl G.
Electrons are parts of atoms, atoms are
parts of molecules, molecules are parts of mitochondria, mitochondria are
parts of cells, cells are parts of organs, and organs are parts of the human
body. So, are parts of parts that are parts of parts that are parts of
parts that are parts of parts that are parts of parts, parts?

Or, like the guy at the fast-food chicken place said, "parts is parts". ;-)

Cheers!
Rich

[Robert Israel]

Post by Rich Grise

Post by Carl G.

Post by Kevin Stone
I was pondering what parts of the human body are the fastest moving? Let's
o Nerve signal (not a part of the body, but could be the quickest)
o Eyelid during blink
o Fingers whilst being clicked
o Parts of the respiratory tract whilst sneezing/coughing
o Tips of fingers during some types of activity
Fastest voluntary muscle?
Not a very big list yet, but it's very early...

What is your definition of "part". The smaller "parts" usually have faster
speeds. Are parts of parts parts? Are photons a part of the human body?
Electrons also move fairly fast.

Are you talking about their orbital speed in the Bohr model? If you're
talking about current, the charge moves at C * V, but the electrons move
a few inches an hour. (V = velocity factor, a number less than 1, that
depends on the medium)

Not sure what you mean by "the charge moves at C * V". The few inches per
hour would be the drift speed of the conduction electrons in a wire.
The random thermal motion of these electrons is much faster, maybe 1000
km/s, it's just a very slight bias towards motion in a certain direction
that produces current. Of course there are no wires in a typical human
body. Electric currents in the body would be carried by ions, mainly
Na^+ and Cl^- I guess.

Post by Rich Grise
Nerve impulses seem to be fairly quick.

At most a little over 100 metres per second, and there's no moving "part"
there, just a wave.

Post by Rich Grise

Post by Carl G.
Electrons are parts of atoms, atoms are
parts of molecules, molecules are parts of mitochondria, mitochondria are
parts of cells, cells are parts of organs, and organs are parts of the human
body. So, are parts of parts that are parts of parts that are parts of
parts that are parts of parts that are parts of parts, parts?

Or, like the guy at the fast-food chicken place said, "parts is parts". ;-)
Cheers!
Rich