OCEAN OF KNOWLEDGE

What is Blood? Blood circulates through the body delivering nutrients and removing waste materials. Blood is made up of red blood cells, white blood cells, and platelets all suspended in plasma. Plasma- About 55% of your blood is made up of plasma. Plasma is a liquid made up of proteins, minerals, dissolved salts, and water. Red Blood Cells- Your body produces two million red blood cells every second. Red blood cells are responsible for carrying oxygen from your lungs to your cells and for carrying carbon dioxide from your cells to your lungs where it is exhaled. White Blood Cells- White blood cells defend the body against attack from foreign organisms, such as bacteria and some viruses and form antibodies that protect the body from future attacks. If the body is invaded by harmful organisms, the production of white blood cells increases dramatically. When a white blood cell encounters a smaller organism, it simply engulfs it. If the invading organism is larger, a number of whi...

The Circulatory System                      Introduction The first system you’ll be examining in this learning package is the circulatory system. The circulatory system transports substances around our bodies; it delivers essential nutrients to every one of our cells, and it helps to transport waste products to waste-disposal sites—the lungs, the skin, and the kidneys.