B like blood

B as in blood

Do you ever wonder what makes up blood?  Unless you need to have blood drawn, donate it or have to stop its flow after an injury, you probably don't think much about it.  But blood is the most commonly tested part of the body, and it is truly the river of life.  Every cell in the body gets its nutrients from blood.

Blood is a mixture of two components:  cells and plasma.  The heart pumps blood through the arteries, capillaries and veins to provide oxygen and nutrients to every cell of the body.  The blood also carries away waste products.

The adult human body contains approximately 5 liters (5.3 quarts) of blood; it makes up 7-8% of a person's body weight.  Approximately 2.75-3 liters of blood is plasma and the rest is the cellular portion.

Plasma is the liquid portion of the blood.  Blood cells like red blood cells float in the plasma.  Also dissolved in plasma are electrolytes, nutrients and vitamins (absorbed from the intestines or produced by the body), hormones, clotting factors, and proteins such as albumin and immunoglobulins (antibodies to fight infection). Plasma distributes the substances it contains as it circulates throughout the body.

The cellular portion of blood contains red blood cells (RBCs), white blood cells (WBCs) and platelets.  The RBCs carry oxygen from the lungs; the WBCs help to fight infection; and platelets are parts of cells that the body uses for clotting.  All blood cells are produced in the bone marrow.  As children, most of our bones produce blood.  As we age this gradually diminishes to just the bones of the spine (vertebrae), breastbone (sternum), ribs, pelvis and small parts of the upper arm and leg.  Bone marrow that actively produces blood cells is called red marrow, and bone marrow that no longer produces blood cells is called yellow marrow.  The process by which the body produces blood is called hematopoiesis.

Blood Types:

A, B, AB, and 0.  The blood types are determined by proteins called antigens on the surface of the RBC.

U.S. Blood Type Distribution According to the American Association of Blood Banking, these are the percentages of different blood types in the U.S. population: •        A+:  34% •        A-:  6% •        B+:  9% •        B-:  2% •        AB+:  3% •        AB-:  1% •        O+:  38% •        O-:  7% Donating blood: Did you know that you can reduce your risk of heart disease and save a life at the same time?  That’s right!  According to studies published in the American Journal of Epidemiology, blood donors are 88% less likely to suffer a heart attack and 33% less likely to suffer any type of cardiovascular event.  Why is that?  Well, researchers aren’t 100% sure, but believe it may be due to either one of two things. The first theory is that blood donors must be considered “healthy” before they roll up their sleeve, so they are less likely to suffer heart disease because they are already in good health and probably have lower blood pressure and cholesterol levels that non-blood donors. The second theory is that iron has a significant impact on atherosclerosis, or hardening of the arteries. When you give blood you are removing 225-250 milligrams of iron from your system, thus cutting your risk of heart disease. So this is another good reason to consider donating blood!!!