Oxyhemoglobin would have more oxygen in it (artery, coming from the heart), deoxyhemoglobin would have less oxygen in it (vein, going to the heart). They absorb different parts of light (numbers are of the wavelengths (colors)) and what is reflected back is different colors.
They’re saying that oxygenated hemoglobin absorbs less light at the 660 nanometer wavelength, which is within the red part of the spectrum. Since less is absorbed, more is reflected back to you, so you see more red. The 940nm part is a red herring: it’s in the infrared part of the spectrum, so you can’t see it anyway. I dispute the part about deoxyhemoglobin’s blue color, of course.
I was just thinking that if the veins are blue, there’s no reason to think that the blood is blue. If she’s not using that argument, what argument is she using? (If she’s like a lot of my relatives, it’s the ‘everyone knows that’ argument.)
I’m enjoying everyone else’s links. Thanks for asking the question.
I seem to remember being taught that as well. I think probably the gist of what we were being taught was that, “veins look blue because the blood is mostly deoxygenated”, and either the teachers or us foolish children got confused and thought this meant that deoxygenated blood is blue.
Thanks. This link ought to blast her out of the water.
Close. Somebody, probably at nursing school, taught her this, so she believes it, so it’s a fact. At this point it’s not so much an argument as, well, see the Monty Python argument sketch.
Actually, she is. If she weren’t, I wouldn’t waste my time. She’s just not thinking it through.
Teachers are no different (sorry to say) from the lay public when it comes to a lot of things, particularly dealing with nature. They are no longer required to be well educated in science, nor history, nor geography, nor the arts, nor mathematics. (Notice what their evaluations turn on: reading scores). And they are just as prone to promulgating old wives tales and misconceptions as your next door neighbor. However, they do so with greater credibility and gravitas than your neighbor. We are becoming a nation of ignoramuses partly because of who’s running the schools.
Claimer: I am in teacher education and taught middle school for 35 years. I know from where I speak. It’s not pretty but it’s true.
Queen Elizabeth II has blue blood, so do her sprogs and other royalty ::removes cap and tugs forelock::
The rest of us mere mortals just have common or garden red stuff which is far inferior
I work as an embalmer, so I see veinous blood literally by the gallon. It’s usually dark red, about like cranberry juice, sometimes darker, almost purplish, although that’s usually when the person’s been dead for a while. Of course it’s hitting the air when it comes out, but it’s pouring out so thick that I don’t think it could change color without me being able to see it happening, and I never have.
I wouldn’t call veins white by any stretch of the imagination. The walls are almost completely translucent, like a bratwurst skin, but even thinner. Arteries, on the other hand, are white, but the walls are thick enough that you’ll never see the much brighter red blood inside them without cutting one open.
Any idea how acidotic the blood is by the time it gets to you? Due to the Bohr Effect (and probably other processes following death) I don’t think the hemoglobin would be able to bind to oxygen very well after death anyway.
Can you do an “Ask the Embalmer” thread? Pretty please.
OK, I’m blowing the tanks on this to show that indeed “It’s taking longer than we thought.”
In the tv series “Untold Stories of the ER,” an episode recently (orignal air date, Feb 2012) showed a doctor needing to insert an IV into the femoral vein. The narrator says, referring to hitting the femoral vein as being tricky since it’s so deep, indicates that when the doctor pulls back on the syringe, he wants to see “bluish-purple, the color of deoxygenated blood.”
Not only was it mentioned in the narration, but in the reenactment, when the doctor (actor) pulls back on the syringe, the color filling it in did indeed appear to be blue. Actually, the syringe itself was bluish, but even with that, I think the fluid representing the venous blood was also bluish.
The episode had three vignettes: “Rottweiler in the ER,” “Broken Heart,” and “Suspicious Rash,” with the middle one having this scene. The writers for the episode were Jennifer Little, David Massar, and Linda Watt, although I don’t know which writer(s) were responsible for which vignette(s).
Because it’s driving me crazy: venous.
Thank you.
Just in case the OP is still arguing with somebody about it after all these years, Cecil also discussed it here: “Is there really a race of blue people?” (Discussion of the “Blue Fugates”, July 24, 1998, with additional updates.)
[sub](Just skimmed this zombie thread; didn’t notice if anyone else mentioned that yet. Zombies definitely don’t have red blood. Coagulated black, maybe?)[/sub]
Venous has blue genes.
A doctor of mine once told me that venous blood in patients with ginormous cholesterol figures could be seen as milky white, as the darn fat particles (?) themselves were dissolved in the free-flowing blood.
I asked a phlebotomist about this and she said sometimes little white globules scurry by.
Anyone experienced this? This would seem to add another color to the spectrum (ignoring that white is all frequencies, etc.).
Not sure what qualifies as an “argument”, but anyone who wants visible proof just needs to go doneate blood. They can witness blood going directly from their vein through airless tubing into an empty bag, and it is a deep red color. Or really just have blood drawn for any blood test, it goes directly into vacuum tubes and the effect is the same.
I am a retired science teacher. I hereby state that I and most science teachers I have met in the U.S. have never taught that venous blood is ever blue.
I wish I could say the same about some elementary school teachers I have talked to.
Not so much cholesterol but triglycerides. The proper term is “lipemia” or “lipemic” blood. In my experience, triglyceride levels over 1000 mg/dL will begin cause this phenomenon, making the blood look pink to nearly white in extreme cases. I can recall handling several tubes where the blood looked nearly white, with pink strips roiling around when the tube was inverted. This played hell with most of the lab tests we performed, and we had to use an air-driven ultracentrifuge to separate the triglycerides from the serum to be able to run chemistry and toxicology tests.
Ok, and I am a former middle school teacher who had numerous discussions /arguments with former colleagues about this. Many held the wrong view on the matter. I also taught graduate science methods courses to students who almost all believed venous blood to be blue. I also have observed tons of teachers in tons of classrooms who promulgated the same erroneous b.s. in fact, I focused a large part of my coursework on misconceptions and how to identify them and how to address them. The blue blood one is but one of many that are deeply entrenched in the public psyche, and unfortunately that includes teachers. Don’t ask about sugar and hyperactivity!
Are there any even remotely plausible medical conditions that could cause blood being drawn from someone to actually appear blue, rather than purple-ish or black?