BLOOD

We have begun to discuss the Cardiovascular system. This week we focused on blood. I want to explain the parts of blood and it's three main functions. Blood is a viscous fluid making it flow slower than water. It's temperature is 38 degrees Celsius and makes up 8% of our total body weight. The average male/pregnant female has 5-6L of blood and non pregnant females have 4-5 L. Blood is made up of about 55% plasma, which is a watery fluid. Within the plasma are proteins, water, and a small amount of waste products. Blood also contains 45% of formed elements. These elements are platelets, rbc's, and wbc's. The rbc's make up about 99% of the formed elements. Functions of blood include transportation, regulation, and protection. Blood transports oxygen from the lungs to the body and gases (CO2) from body cells to the lungs. It also transports nutrients to the body cells and waste products away from the cells and out of the body primarily through urination. Blood also transports hormones from the endocrine glands to other body cells. Blood helps to regulate pH (normal pH of blood is 7.35-7.45), regulate body temperature (thermoregulation), and regulate blood pressure/blood volume. Blood circulates wbc's to help "fight infection". Blood has clotting factors to prevent excessive blood loss.
I donate blood pretty regularly because I know that it can save up to three lives. I have also donated platelets, which can help people with thrombocytopenia (low platelet count). I am able to give a pint of blood in under five minutes.