Blood Vessels
Veins: All in Vein
Veins are similar to arteries but, because they transport blood at a lower pressure, they are not as strong as arteries. Like arteries, veins have three layers: an outer layer of tissue, muscle in the middle, and a smooth inner layer of epithelial cells. However, the layers are thinner, containing less tissue.
Veins receive blood from the capillaries after the exchange of oxygen and carbon dioxide has taken place. Therefore, the veins transport waste-rich blood back to the lungs and heart. It is important that the waste-rich blood keeps moving in the proper direction and not be allowed to flow backward. This is accomplished by valves that are located inside the veins. The valves are like gates that only allow traffic to move in one direction.
The vein valves are necessary to keep blood flowing toward the heart, but they are also necessary to allow blood to flow against the force of gravity. For example, blood that is returning to the heart from the foot has to be able to flow up the leg. Generally, the force of gravity would discourage that from happening. The vein valves, however, provide footholds for the blood as it climbs its way up.
Blood that flows up to the brain faces the same problem. If the blood is having a hard time climbing up, you will feel light-headed and possibly even faint. Fainting is your brain's natural request for more oxygen-rich blood. When you faint, your head comes down to the same level as your heart, making it easy for the blood to quickly reach the brain.
Because it lacks oxygen, the waste-rich blood that flows through the veins has a deep red color, almost like maroon. Because the walls of the veins are rather thin, the waste-rich blood is visible through the skin on some parts of the body. Look at your wrist, or hands, or ankles. You can probably see your veins carrying your blood back to your heart. Your skin refracts light, though, so that deep red color actually appears a little blue from outside the skin.
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1) What does arteries mean.
2) What does capillaries mean.
3) Why are they comparing human life with the blood veins.
4) Doesn't that also happen if you don't eat all day.
5) What does this mean and what is it trying to say.
SUMMARY
In the article "Blood Vessels" it talks about what blood vessels do to you. The main argument of "Blood Vessels" is the importance of how our blood runs through the veins.
In the first paragraph it talks about how veins are similar to something called arteries but they are totally different. Veins and arteries they both have three things which are an outer layer of tissue, a muscle in the middle, and a smooth layer of epithelial cells. But one of the differences is that in the arteries are thinner and contain less tissues.
In the second paragraph it talks about how the blood runs through your veins. The article says that when the blood stops it like it is stuck in traffic it can run through like it is suppose to. In the article also said that that the blood can't run backward but it can only fun forward. If your blood ever move and opposite directions then it is because you are laying down and your blood can only run down.
In the third paragraph it mainly talks about how your blood also affects how you faint. What the article said that the cause you to faint is what when the blood has a hard time climbing up then that what makes you light headed and you suddenly faint. This wasn't in the article but when you also eat nothing in the whole day also makes you faint because your body doesn't have much protein to sustain you for another minute so you get light headed and faint . Another thing that the third paragraph said that that your head comes to the same level as your heart.
In conclusion the article "Blood Vessels" is mainly about how your blood goes threw your vessels. In my opinion I think that this article was pretty cool and it had information and words that I did not know.
What i know about the eye is that it helps you look. Another thing that i know abnout the eye is that you can harm your eye. the way you can harm your eye is if you watch to much T.V or use the computer alot. The reason that your eye starts to lose its sight is because when your eye gets to much light it blacks out sometimes and you can turn blind or you just have to wear glasses or contacts ( did you know that contacs are convex). One example to my last sentance is that you eye is like a light bulb when it has a little life left you still have light but when all the light has been used it blacks out, just like your eyes. When you get hit in the eye with a ball it knocks off some light that is why you almost can't see that well with a black eye. And when your eye turns back to normal you don't have the same vision you used to have. The reason is becasue a hard object that