why do we need blood in our body

If blood didn t circulate through our bodies, carrying oxygen and nutrients, we wouldn t be able to live. Blood is so important to life that the body constantly makes new blood. To do this, the body must produce the liquid part of blood, called, and the cells that float in it. Plasma is made mostly of water and salts that we absorb through our digestive tracts every day. Its job is to deliver nutrients and water throughout the body. Ninety-nine percent of the blood cells floating in plasma are red blood cells, which carry oxygen from the lungs to the rest of the body and give blood its red color. The average life of a red blood cell is four months. What Happens After That? The spleen continuously destroys millions of old red blood cells, recycling the iron to make new red cells.


White blood cells, which are part of the immune system, and platelets, which help with blood clotting at a site of injury, also float in plasma. They have much shorter life spans than red cells and also are replaced continuously. If you ve ever seen a bone cut crosswise, with soft tissue called marrow inside, then you ve seen where blood cells are made. Bone marrow contains special blood cells, which constantly divide to produce new cells to replace the ones that have been destroyed. Why all this bloody business in the bone marrow? The body s process of forming new blood cells helps you recover if you lose blood to an injury, and it also helps blood perform its many functions despite cell damage and loss.
Caution!


Today's Wonder of the Day has been known to attract and vampires. What are we talking about? , of course! It's the stuff that runs throughout our bodies. We need it for life, so we want to keep it inside where it belongs. When we get and it comes outside the body, that's when we have troubles and get squeamish! So let's work hard to keep our inside. But have you ever stopped to think about where it is inside you? Does it stay in one place? No! It moves around. A lot. Let's take a closer look at and what it does inside our bodies. Your body has quite a bit of in it. The bigger you get, the more you have.


Most of us have around a gallon or more of. If you could buy a gallon of at the supermarket, it might be fun to look at the ingredients to see what's in it. When your body makes new, it follows a careful recipe that mixes together four different ingredients: cells, cells, platelets, and. Each of these ingredients has special functions within the. cells carry to the areas of your body that need it. cells help to fight infections. Platelets will help you stop bleeding if you get a cut. carries a variety of things, such as nutrients, proteins, and hormones, throughout the body. Your is a critical part of your circulatory system. is a powerful muscle that pumps your throughout your body в from the top of your brain to the tips of your toes.


The pathways your takes consist of different types of vessels, including arteries and veins. Your arteries carry filled with away from the heart to the rest of your body. Because the heart is a strong muscle, this doesn't take long. Did you know it takes less than a minute for to reach every part of your body? After is delivered to the areas of your body that need it, your returns to your heart through your veins. Along the way, it picks up and other things your body wants to get rid of. It's kind of like taking out your body's trash! Thanks to your lungs, your is replenished with upon returning to the heart. It's then pumped back out to the rest of the body.


This goes on and on, over and over your entire life! This, movement of throughout your body is called. Although all functions in the same way, did you realize there are different types of? Depending upon what types of proteins are found in your cells, you will have one of eight types, named using the letters A, B, and O. The eight types are: A negative, A positive, B negative, B positive, O negative, O positive, AB negative, and AB positive. No is better or worse than another. They're just different. Some are rarer than others. If you have a rare, it can be more difficult to find a if you ever need one. That's why people with rare types are often encouraged to become donors.