First thing: Blood is *never* blue. Blood is described as dark red (venous) or bright red (arterial). Our veins look blue because we are looking at them *through* our skin. The blood inside them is dark red and it doesn't reflect light very well. The blood you see when you get hurt is usually venous blood. Arterial blood comes out in spurts. It spurts every time the heart beats. I hope you never see that.
About Ashleigh's first question: I asked Mr. Johnson that and he said something about when the blue blood and air meet. Why does oxygen-poor blood have to be blue and oxygen-rich blood have to be red? Could there be a situation when your heart could be bigger or smaller?
Check out the answer to the first question above about blue and red blood. The second question can be answered thus: If your heart is diseased (heart attack, viral infection, etc.) it can become much larger. It will then become a very poor pump. If you want to know the name for a big flabby heart it is - dilated cardiomyopathy. Sometimes the heart muscle gets thicker but the heart doesn't get much bigger, this is known as hypertrophic cardiomyopathy. Both conditions can be very bad.
Well, about Heather's question I know 2 reasons. They are not the real scientific answers. Your heart gets bigger when you are nice, caring, and loving. It gets smaller when you are mean, disrespectful, and uncaring. Right?
I like the way you think. Thanks for the q's. See, ya!
| Heather and Ashleigh:
January 13, 1997
Dear Mr. D Hi!! How are you? We are fine. We as in Heather and Ashleigh.
Heather: Thanks for writing back to us. How was your weekend? I lost that calorie info so tonight I will print it out again. Ashleigh is going to call and remind me. How come your blood looks blue but isn't blue?
|Mr. D: Your *blood* does not ever *look* blue. The blue things you see under your skin are veins. Veins are really whitish in color but because the blood is dark and the skin difuses the light, the veins *look* blue.|
|Ashleigh: Thank you again for writing back. Thank you for the answers. I will tell Mr. Johnson about this. I do not even know if he knows about the blood thing. I like the way you think too.|
|Heather: So when you bleed the blue blood does not meet the air and turn red ?|
|Mr. D: No, the dark red blood *may* pick up a little oxygen and brighten up a slight bit, but your blood is *never* blue.|
|Ashleigh: I forgot to say something : Thank you for all of the technical talk. (Ha Ha) You could have just said veins instead of venous and arteries instead of arterial but that is okay. I was just telling you that.|
|Sorry this letter isn't as long but we have to go to class.
Your tired Keypals,
Heather and Ashleigh
|Mr. D: Thanks for writing. You both brighten my day.|
January 15, 1997
Heather: I think I understand about the veins and blood.
|Mr. D: Are you sure?|
|Ashleigh: Okay, so your veins are really a whitish color. Right ? So if your veins aren't the color we see, arteries are red right? Doctors see that the arteries are red or are they a different color too ? I will translate this to you: Are the arteries the color we think they are (red) or are they a different color ?|
|Mr. D: Actually the veins and arteries look similar when you remove the skin and can see them directly. Veins are a slightly more "bluish" white and the walls are thinner than arteries. Arteries, since they are a *high pressure* system pulsate (this is what you feel when you check your pulse).|
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