Red river

Blood is actually connective tissue, the only liquid type in the human body.

How much blood we have depends on how big we are — blood accounts for about 8 percent of body weight, on average about five quarts (roughly five liters). More than half of blood is plasma, a yellowish fluid that itself is mostly water.Blood splatter

Plasma carries all the things the cells need when it begins its journey out from the heart. The bulk of its cargo is the 25 trillion red blood cells filled with oxygen, but it also carries infection-fighting white blood cells and platelets that will clot the blood when needed, as well as vitamins, electrolytes, hormones and other materials.

Animals that use a protein called hemoglobin to store oxygen have bright red blood when it's fully oxygenated, because hemoglobin contains iron. (Spider blood, for example, contains copper-rich hemocyanin, and is blue when oxygenated.)

Red blood cells are manufactured in bone marrow, and circulate in the blood for about four months. They look like fat plates, flat but curved, a shape that allows them to squeeze into capillaries. They have no nucleus, devoting as much space as they can to hemoglobin.

One entire circulation of the blood through the body of the average resting adult, given that five quarts of blood, takes about one minute. Without the life-giving oxygen it carries, the most vulnerable cells, including those in the brain, would begin to die within about five minutes, and organs would start shutting down just a few minutes later.

Image from Wikimedia Commons

Fascinated with blood

I'm embarking on a series of posts about blood. I can't help it. I'm fascinated with blood.

The final classic symptom of amniotic fluid embolism is disseminated intravascular coagulation (DIC). When I suffered an AFE during the birth of my younger daughter, I was nothing but classic.

Edward Cullen
Also fascinated by blood

I hemorrhaged to the point where all the blood ran out of my body three times over. I didn't die from this event because I received a total of 87 units of blood and blood products — whole blood, plasma, cryoprecipitate and extra clotting factor.

I am alive to tell our birth story because thoughtful strangers had donated their blood, a large stockpile of blood was five minutes away when I needed it, and because a whole raft of people had done the work over centuries to figure out how to make someone else's blood work in my body.

And, by 1997, the blood supply had been made safe again, after a horrific tainting with the HIV/AIDS virus.

The bill for my daughter's birth, including two surgeries (a Caesarean section and separate hysterectomy performed to stop the bleeding), a stint for the baby in the high-risk nursery, a night for me in the intensive-care unit and an additional four days in the hospital, was $100,000 all those years ago.

Blood accounted for $13,000, more than 10 percent of the total.

Blood was a major factor in giving our birth story a happy ending. Fascinating!