The Book of Blood: From Legends and Leeches to Vampires and Veins Read online

  Table of Contents

  Title Page

  Table of Contents

  Dedication

  Copyright

  Introduction

  CHAPTER 1

  CHAPTER 2

  CHAPTER 3

  CHAPTER 4

  CHAPTER 5

  CHAPTER 6

  CHAPTER 7

  CHAPTER 8

  CHAPTER 9

  CHAPTER 10

  CHAPTER 11

  Bibliography

  Photo Credits

  Acknowledgments

  Index

  To LEE, ANNE, ROBERT,

  EDWARD, MARGARET,

  JAMES, AND MICHAEL.

  Apparently, blood really

  is thicker than water.

  Copyright © 2012 by HP Newquist

  All rights reserved. For information about permission to reproduce selections from this book, write to Permissions, Houghton Mifflin Harcourt Publishing Company, 215 Park Avenue South, New York, New York 10003.

  Houghton Mifflin Books for Children is an imprint of Houghton

  Mifflin Harcourt Publishing Company.

  www.hmhbooks.com

  The book design is by YAY! Design.

  The text of this book is set in Goudy Old Style.

  Photo credits are on [>].

  Library of Congress Cataloging-in-Publication Data

  Newquist, H. P. (Harvey P.)

  The book of blood : from legends and leeches to vampires and veins /

  HP Newquist.

  p. cm.

  ISBN 978-0-547-31584-3

  1. Blood—Juvenile literature. I. Title.

  QP91.N45 2012

  612.1’1—dc23

  2011025134

  Manufactured in China

  LEO 10 9 8 7 6 5 4 3 2 1

  4500353174

  Introduction

  RED. WET. STICKY. GROSS. MOST OF ALL, RED. BRIGHT RED.

  All of these words are used to describe the most important liquid in your body: blood.

  It’s not just you, of course. Fish, birds, mammals, insects, and every person on the planet has blood, too.

  The sight of blood from a wound causes many people to feel faint.

  Blood is pervasive. Blood—as a symbol, as a living tissue, even as a word—is important to every culture in the world. It is used in language to describe extreme situations or events. For example, “blood brothers” are people who have a very close relationship, while the phrase “bad blood between them” describes people who are spiteful toward each other. “Blue bloods” are members of a royal or very rich family who are thought to be different from common people—right down to the color of their blood. A “blood oath” is an oath that can never be broken. “Cold-blooded” refers to someone who appears to have no feelings or compassion. “Bloodthirsty” is used to describe the rulers of countries who regularly engage in war, with battles that might end up as “bloodbaths.” Something that makes you extremely angry makes your “blood boil.” And in England, “bloody” is used as a curse word.

  Despite its importance to our lives, there has always been an “ick” factor surrounding blood. From vampires to scary movies, the thought of blood outside our bodies still gives most people the shivers. Bloodsucking vampires, blood transfusions in a hospital, and even the blood from a wound make many people queasy. They don’t like to think that this red fluid fills up our insides.

  Blood does give us a reason to pause, perhaps because of its bright red color. All over the world, red is the color of warning and danger. From stop signs and stoplights to fire engines and the flashing lights on ambulances, red is a color that we pay attention to. Similarly, the sight of blood causes us to freeze in our tracks.

  There is more to blood than that it’s red and kind of gross. It is an extremely complex fluid that moves through you your entire life without ever stopping. Most important, it keeps you alive. Blood delivers fresh oxygen to your cells, protects you from disease, and sweeps the waste from your organs from the moment you are born.

  Scientists are still discovering things about blood almost every day. In fact, only in the last one hundred years have scientists come to understand just what blood is and what it does. And what it is, and does, is quite amazing.

  CHAPTER 1

  Real Blood

  There is probably nothing scarier to many of us than seeing blood suddenly rush out of a wound. But without blood, people couldn’t live. That red liquid is keeping you healthy, allowing you to think and play, and making sure your body gets everything it needs to grow and stay alive.

  You’ve seen blood, probably coming out of your own body. This doesn’t happen on purpose: You run into someone while playing a game, bang your face, and your nose starts bleeding. You open an envelope with your finger, get a paper cut, and then a razor-thin line of blood rises on your skin. You fall off your bike, and your scraped knee spills blood. You lose a tooth, and blood shows up in your mouth.

  You see the blood, and you experience a moment of shock or fright that it has shown up outside your body. But the red liquid stops flowing, hardens, or is wiped off, and then you forget about it. It was there briefly, and then it went away.

  There probably wasn’t much blood, maybe a tablespoon at most. It was only a small amount of the blood that continued to swirl through your body, rushing as fast as if it were flowing through a faucet. You went back to what you were doing, and your blood kept doing what it has done ever since you were born: keeping you alive.

  Blood looks too simple to be so important: just a bright red splash of liquid that seems as if it isn’t much different from paint or fruit juice or cherry-colored water. But blood is not a simple red liquid. It is very complex and contains many components, which are so small you need a microscope to see them. Think of these components as being similar to the ingredients in a chocolate milk shake. While a glass of pure orange juice is made up only of the liquid squeezed from an orange, a chocolate milk shake is made up of many different things. There is the milk, sugar, and flavoring that create the ice cream. Then there is chocolate syrup, which has cocoa butter, sugar, corn syrup, preservatives, and a host of other ingredients. When blended together, these unrelated ingredients form one unique liquid: a milk shake.

  Like a chocolate milk shake, a lot of things go into making your blood. This starts with plasma, a pale, gold-colored liquid that makes up half of your blood. Most of your plasma, about 90 percent, is made up of water. The watery nature of plasma helps blood flow through your body. Think of plasma as the river in which all the other blood parts float along together.

  One drop of blood is mostly plasma, with red blood cells, white blood cells, and platelets floating inside it.

  The next biggest ingredient in blood is red blood cells. These are round, partly flattened cells that carry hemoglobin. Hemoglobin is a protein, and proteins are substances that contain elements such as oxygen, nitrogen, and carbon. Living beings use proteins to carry nutrients and to trigger many biological processes. Hemoglobin, in particular, contains iron atoms that attract oxygen atoms. When red blood cells enter your lungs, the hemoglobin picks up oxygen and carries it to other parts of your body.

  Red blood cells are shaped like disks with slight depressions in their center. They get brighter red when they fill with fresh oxygen.

  Hemoglobin turns bright red when it is filled with oxygen* And even though plasma is gold colored, nearly half of your blood is made up of red blood cells, so hemoglobin gives your blood its distinctive color.

  Then we have white blood cells. There is approximately one white bl
ood cell for every six hundred red blood cells—that’s approximately 1 percent of your total blood—and they live for just a couple of weeks. Because there are so few of them, the white cells don’t affect the color of your blood. (If there were as many white cells as there are red cells, we might be talking about pink blood.) White blood cells are like bodyguards for the inside of your body. They attack and eat bacteria, they eat dead cells in your body, they fight off parasites, and they tell your body when it needs to protect itself. Think of them as microscopic attack dogs. They also carry your DNA, which is the code to how your body is structured.

  Aside from red and white blood cells, there are platelets, the smallest of the blood particles. Platelets are initially shaped like little plates, which makes it easy to remember their name, but when they go to work, they extend in many directions, like a star or a squid. The function of platelets is to stop blood from flowing out of you. When you get a cut or a scrape that starts to bleed, the platelets are suddenly exposed to air. They swell up and begin a chemical reaction that clogs up the blood flow near the cut. If you didn’t have platelets, you would bleed to death.

  White blood cells are far outnumbered by red blood cells.

  Platelets help keep your blood inside your body when you are injured.

  There are lots of other things in your blood, many of them floating around in the plasma. They include various proteins, vitamins, and glucose (a form of sugar), all of which are used to either nourish your body or help it fight off disease.

  Your blood is a fluid rich with different-colored ingredients that do many things: golden plasma that transports blood cells, red blood cells with hemoglobin, white blood cells for protection, and platelets for clotting and repair. Inside your body there is about a gallon of this blood, the equivalent of a big jug of milk.

  Because it contains living cells, blood is more than just a liquid. It is actually considered tissue. The definition of “tissue” is any grouping of cells that work together to perform a specific function or create a specific organ or part of the body. The heart and lungs and skin are all made of different forms of tissue. In the scientific world, blood is its own kind of tissue, even though it is a very fluid substance.

  Red blood cells, white blood cells, platelets, and plasma are the primary components of blood.

  * * *

  BREAKDOWN OF BLOOD COMPONENTS IN A CENTRIFUGE

  When blood is spun around quickly in a centrifuge, it separates into its three main parts based on how heavy each component is. The top half, or roughly 55 percent, of the separated blood is the almost clear gold-colored plasma. The bottom segment, just 45 percent, is made up of all the heavy elements related to red blood cells and hemoglobin. In the middle is a small layer—barely 1 percent—of white blood cells and platelets. They are slightly heavier than plasma, but lighter than red blood cells. This is called the buffy coat because of its off-white or buff color.

  Blood separates into its different parts when it is processed in a lab: red blood (on the bottom), white blood (thin strip in the middle), and plasma (on the top).

  * * *

  Blood moves around your body through a vast network called the cardiovascular system. This includes your heart, your arteries, your veins, and your capillaries (the really tiny blood vessels). Various scientists refer to this network as the circulatory system. Others use the term “circulatory system” to mean both the cardiovascular system and the lymphatic system, which is part of the immune system and helps drain excess fluids from your organs. To keep it simple, we’re going to use the term “circulatory system” from here on. It’s the most commonly used term, and will help you better understand how blood moves—in a circular manner—throughout the body.

  * * *

  BLUE BLOOD?

  While it is in your body, your blood is always red. It is never blue, although some people think that blood is blue because some veins look blue underneath our skin. The fact is that oxygen-rich blood is bright red, and when red blood cells give up oxygen—and instead carry waste from your body—they lose that brightness. Blood turns dark red as it travels through you, becoming almost maroon or burgundy colored, before lightening again when it absorbs air in the lungs. The idea that blood is blue in your body is a myth.

  In fact, your veins aren’t blue, either. Veins appear blue under your skin because of the way light interacts with various layers of your skin, with the area around your veins taking on a darker color. And when you see blood vessels next to other parts of your skin, you perceive them as bluish in color.

  * * *

  Think of the circulatory system as a highway or a waterway. Blood flows through it like traffic, carrying everything your body needs, as well as most of what your body wants to get rid of. Like a busy highway in a big city, traffic never stops: it crisscrosses over itself and loops around and up and over, and eventually everything gets to its proper destination.

  The circulatory system reaches into every part of your body. You have so many blood vessels that they would stretch 100,000 miles.

  The circulatory system is so completely spread out over the human body that if you poke a needle into any part of your skin, you will draw blood. This is because there are approximately a hundred thousand miles of veins, arteries, and capillaries in your body. If all of these blood vessels were stretched out in a line, they would circle the Earth four times. You can see capillaries—large ones—by looking at your eyeball in the mirror or by looking up close at a friend’s eye. Those little red vessels in the white part of your eyeball are carrying blood right into your eye from your heart.

  Each day, your heart beats about a hundred thousand times, pumping blood to every single corner of your body. Your heart pumps your blood over and over so many times over the course of twenty-four hours that it is pumping the equivalent of two thousand gallons a day. Two thousand gallons is enough to fill a swimming pool.

  Unlike with many other systems in your body, you can actually see and feel the circulatory system at work. You can feel your heart pumping, you can sometimes see your arteries pulsing (especially in your wrists and arms), and you’ve seen blood come out of your body, probably through cuts, loose teeth, or a bloody nose.

  That brings us to the big question: what does blood actually do?

  We’re fortunate to be living in an age when we can answer that question. Before the 1900s, there were a lot of misconceptions about blood. It was misunderstood and frightening, part of monster stories and mythology. And not so long ago, doctors believed that curing diseases meant injecting animal blood into people ... or taking as much blood out of a person as they could.

  To find out what blood does, we’ll start by looking at why blood has always been so mysterious.

  CHAPTER 2

  The Mystory Inside

  Creatures have bled since the dawn of time. Dinosaurs bled, mammoths bled, and the Neanderthals (sometimes referred to as cavemen) bled.

  Modern humans, who have been around for a little over two hundred thousand years, saw blood regularly. It poured from the animals they hunted. It flowed from their own bodies when they were injured. This might have happened when they fell or when animals attacked them. A savage animal attack—by a predator such as a lion—would have been very dramatic and involved a great deal of blood.

  After a predator had finished eating another animal, the only thing left may have been blood on the dirt.

  Early humans had no understanding of what blood was or what it did, but they understood that it was important. They knew that when a lot of blood was spilled on the ground, death was nearby. By being associated with death, blood was certain to have caused fear. It was given the same respect as death.

  Like other powerful images, symbols, and elements of the natural world that weren’t understood (such as thunder, lightning, floods, predatory animals, and death), blood was incorporated into the lives of ancient cultures. It became part of their legends, part of their rituals, and part of their ceremonies. Blood was esse
ntial to myths, legends, and religious traditions long before humans knew what blood was.

  Lamashtu attacked citizens and drank their blood. In this ancient plaque, she is depicted devouring the people around her.

  As far back as 5000 B.C., the people of Mesopotamia (the area of present-day Iraq) had a female goddess known as Lamashtu. She was an evil creature who was jealous of human women, stole their babies, and sucked the blood from the mothers and their newborns. Her existence was used to explain the deaths of infants and of pregnant women. Other evil, blood-drinking beings, like the Babylonian goddess Lilitu and the Hebrew Lilith, are believed to be related to the story of Lamashtu.

  The Hindu goddess Kali, who was associated with change and destruction, was said to drink the blood of her enemies after defeating them on the battlefield. Sekhmet, the warrior goddess of Egypt, also drank the blood of her enemies and was said to drink from the Nile River when the water became bloody. It is likely that some of these female deities were the inspiration for early vampire legends.

  Kali and Sekhmet were ancient deities who were believed to drink blood.

  Blood also played a large part in the Bible, and it was used frequently as a symbol of fear, power, and life—especially when God was involved. In the Old Testament book of Exodus, the Egyptians held the Israelites as slaves. When God demanded that the Israelites be freed, the Egyptians refused. As punishment, God unleashed ten plagues upon Egypt, beginning with the Plague of Blood: