Science questions!?

Question

Lots of questions!
1. Why does the body need oxygen?
2. Describe how carbon dioxide from a cell in your hand leaves your body.
3. The lungs can expand and contract because they have muscular walls. Is this statment true or false? Explain.
4. What structures help increase the absorption of food in the small intestine? How do they do this?
5. How might your muscular system help you stay warm?
6. How might your circulatory system help you stay cool?
7. Why do humans need a complex circulatory system while an amoeba does not?
8. What can happen if arteries in humans become clogged or narrow?
9. What are the three main types of food? What does each type provide for your body?
10. How do smoke or pollutants in the air affect your respiratory system?
11. When people living in rural India emigrate to a city in Canada, they increase their risk of contracting colon cancer. Explain why.

Answer 1

I only know the first one:

1. For Aerobic Respiration

Answer 2

1. the body needs O2 for metabolism. The oxygen is used in aerobic respiration to break down sugars into smaller molecules, which causes a release of energy. The body uses the energy released from the breaking of bonds to power itself.
2. The CO2 attaches to the hemoglobin in the blood (much like oxygen would) and is carried back through the veins to the heart, then the lungs. In the lungs, the CO2 in the blood is routed through progressively smaller vessels until each of the blood cells are able to reach the air breathed in through the lungs. The CO2 is replaced by O2 in the air. The blood then travels back to the heart where it is pumped to the rest of the body and the process starts over.
3. False, the lungs expand and contract through negative air pressure in the chest cavity created by the diaphragm. This sucks air in. The diaphragm pulls down, sucking air in. When it releases, the air naturally flows back out; however, it can be aided by the muscles in your chest. When you forcibly blow air out, they contract your chest, pushing out the air inside.
4. The small intestine has villi lining the inside. These are little tiny structures that look kind of like fingers sticking out in millions of rows. What they do is make the surface area greater, so that there is more space to absorb nutrients from food. For example, if you have a sheet of paper, it takes up an 8.5 x 11 inch space on your desk. However, if you crumple it, you can fit several papers in the same sized space. This is how villi work. They create more space in the intestine so more food can contact the walls and then more absorption can occur in the same sized space.
5. The muscular system is always making heat, because it makes heat when you move because the cells are contracting, which is work. They produce excess energy which is heat. Your body can make heat if you are cold by moving rapidly or shivering.
6. The circulatory system is always losing heat because your blood in some places comes very near to the surface of your skin where there is little or no insulation (fat). Where there isn't any insulation, the heat is exchanged into the air. However, this can be controlled a little bit. The body can control where the blood goes to a certain degree. If you are warm and want to cool off, your body will have more blood go through the vessels in your skin so that more heat leaves. It does this by expanding the vessels there or vasodilation. Likewise, if you need to hold onto your heat, the body will try to keep the blood deeper under layers of fat and muscles. It does this by vasoconstriction.
7. Humans are huge and complex compared to an amoeba and have to transport nutrients, fluids, oxygen, and wastes all over the body. For example, if you drink water, it needs to be moved and distributed to all the cells from your head to your feet. If an amoeba needs water, it can absorb it and since it is just a tiny organism, the fluid reaches everywhere almost immediately.
8. When arteries are clogged or narrowed, the blood to where ever that artery leads is decreased. This means that that body part isn't getting enough oxygen and nutrients. This damages the cells there and they can end up dying.
9. Carbohydrates, Protein, and Fat. They all provide energy, but carbohydrates are used immediately. Fat is stored and used if the body is in desperate need for energy. Fat is also used to make a lot of different things in the body from hormones to cell walls. Proteins are used to build muscles and certain cell fibers. They too can be used for energy, but these are a last resort! You body has to be extremely starved and out of stored fat.
10. They stick inside the lungs blocking air exchange and harming the cells inside the lungs. Sometimes, the cells react violently, or their structure gets changed causing tumors. When air exchange is reduced, so is the oxygen the cells are getting, which decreases the metabolism (or energy) that they have, which can lead to cell death. This causes the body to be weaker and can also cause mucous or fluid to gather in the lungs as the body tries to protect itself. This can cause a nasty cough or pneumonia. Some of the pollutants or smoke is caught in mucous and coughed or pushed out, but a lot is permanently adhered in the lungs.
11. I have no idea. Possibly from the change in diet. In Canada, they are eating a lot of processed foods which decreases their ability to have a bowel movement. This could lead to constipation which is related to colon cancer. Double check this one though.

Answer 3

Ha! Ha! very funny indeed. Thanks for a good laugh!