|Did You Know…?
Red River of Life
Day and night, nonstop, mechanics rush to numerous sites to repair and replace damaged parts, supply vehicles deliver fuel, plumbers are busy repairing leaks and breaks. A cleanup crew continually traverses the ways removing debris, and a police force keeps the peace while an army repels attacks and destroys the enemy.
All this—and more—is part of an elaborate network, which is centrally controlled by an electronic system receiving commands from a super computer beyond description.
Does it sound like an advanced nation in a science fiction movie? No, it is a mechanism right within our bodies. It all belongs to a complex river of life. We call it our circulatory system. But it is far more than that. It is a marvelous feat of engineering, the work of our all-wise Creator.
The Circulatory System
Seventy times a minute, two ounces of blood bursts forth from the left side of the heart to begin its journey through the body. The heart, the body’s strongest muscle, delivers a pounding force against the artery walls 70 times a minute, more than 100,000 times every day—some 2-1/2 billion times during a person’s life. Not even rigid metal pipes could stand this pounding for long! But the God of creation designed the arteries especially for the purpose.
With each impact, the arteries stretch and the strong muscles coiling around them recoil, sending the intermittent waves of blood through a never-ending river of arteries, vessels and capillaries. Stretched out, they would reach 100 thousand miles, long enough to reach around the earth 4 times. So dense is this network of capillaries that no cell in the body is more than a millionth of an inch away from the blood supply. The capillaries are so thin that the tiny red cells must line up in single file and bend and twist to get through.
The farther away from the pumping station, the greater the surrounding muscle, which may wrap two or three times around the smallest arteries. Rhythmically squeezing and relaxing, they force blood to the 10 billion capillaries that fan throughout the body while one-way valves prevent the blood from flowing backwards.
In the outermost branches of this system, blood flow slows to less than a fraction of an inch a second as the blood drops off its load of nutrients and oxygen and picks up a load of waste for its return trip. Finally the blood arrives in the right side of the heart and is immediately pumped to the lungs with the nearly toxic waste. Here it exchanges carbon dioxide for another load of oxygen. (In order to maintain a delicate pH balance, less than 10% of the carbon dioxide is exhaled as another load of oxygen is grasped. And remember, blood is being delivered to the lungs at the rate of about two ounces 70 times a minute at rest. That is an incredible 75 gallons (or more) per hour for a lifetime of perhaps 70 plus years!)
Surely, an all-wise Creator had to be the designer!
The food we eat provides the fuel to keep the cells of our bodies alive and functioning. But for the fuel to burn there must also be a continuous supply of pure oxygen at the incredible rate of about 4 gallons per hour. (And this is when the body is at rest! It can suddenly require more than 75 gallons of oxygen per hour during exercise.)
How did the Creator manage this miracle? Our lungs consist of some 300 million air-filled sacs laced with tiny capillaries that would cover 750 square feet if spread flat. Through walls only 10 millionths of an inch thick, the exchange of carbon dioxide for oxygen takes place. While passing through a tiny capillary in the lungs, less than 1/50th inch long, it drops off carbon dioxide and picks up another load of oxygen before it returns to the heart to be launched into the arteries leading to every cell in the body. Renewed, the blood returns to the left side of the heart, where the heart again propels it into another journey.
But the exchange in the lungs is not so simple. The red blood cell consists primarily of water and a red protein, hemoglobin, its source of power to carry oxygen. In the center of each molecule of hemoglobin (a construction of more than 10,000 atoms), are four iron atoms that act as a magnet holding fast to oxygen that has been absorbed as the red cell passes through a lung capillary. While one hemoglobin molecule can carry only 4 oxygen molecules, every red blood cell has about 270 million of these complex proteins. The iron atoms latch onto the oxygen as the red blood cells pass through the lungs. The hemoglobin is actually about 95% saturated with oxygen.
As a red blood cell passes by a cell of tissue needing oxygen, the red blood cell releases its cargo and at the same time removes deadly carbon dioxide given off by the cell’s burning of fuel. But before the carbon dioxide can be removed, the red blood cell converts it into carbonic acid. The red blood cell then converts the acid to a bicarbonate plus hydrogen, which the blood plasma carries through the veins to the lungs
But the lungs cannot exhale the bicarbonate. So the red blood cells break down the carbonate to carbon dioxide, which the lungs exhale.
|Red Blood Cells by Design?
Even the physical properties of the blood cell show very special design which could never have come about by evolution. Look at the physical shape of the red blood cell, for example. The red blood cell must be designed so that it can provide maximum volume with maximum speed in absorbing gases. And it must be flexible and strong enough to pass many times through canals narrower than itself without being damaged. If you were the designer, how would you design it?
A sphere? Let’s test it in a colored liquid. At first it begins to soak up liquid very rapidly, only to be bogged down as the liquid approaches the center. Obviously not a good choice. Perhaps a disk would be a better shape? Well, it soaks up the liquid all right, but will it hold up? Extraordinary distortion of the red cell occurs as it passes through minute blood vessels with diameters less than itself. Then it must spring back to its original shape. It must make about 75,000 trips through these narrow passages and back to the heart. A simple disk would not meet these requirements. It would probably tear very soon, or-worse-clog the system.
What would be an ideal shape for the red blood cell? A computer-generated design, from a complex equation formulated by science engineers, produced a graphical discoid image. It was dimpled on both sides with rounded edges, the exact shape of the red blood cell. Doesn’t this show that an intelligent Mind designed it? Who, but God?
Capillaries are so thin that the tiny red cells must line up, single file, and bend and twist to get through
Earlier, we compared our circulatory system to an advanced nation with military, police and civilian components working around the clock. The red blood cell is only one part of this complex system. Let’s look briefly at several other components at work.
The life of every cell in the body is dependent on its receiving an uninterrupted supply of nutrients—carbohydrates, proteins, fats, minerals, salts and vitamins, the balance being carefully regulated (improper regulating could lead to death). To supply this never-ending demand is the task of the continuously flowing red river, the blood.
About 55% of the blood is plasma. Plasma carries the many delicately balanced nutrients, repair mechanisms, a means to clean up dead cells, and an army of cells to combat disease and other foreign materials that may enter the body. It also provides a mechanism to dissolve blood clots.
Plasma, which is 90% water, is the substance which makes it possible for the other constituents to reach to all parts of the body. Dissolving and distributing the food we eat, it carries minerals, salts, proteins and fats to every cell.
Blood consists of a diverse society of living, thriving cells which perform specific tasks and co-exist in strict proportions. This balance of these cells to each other is even more critical than the balance of nutrients. A decline in any one of the cells can endanger life.
For the elaborate community to function harmoniously, maintenance is necessary.
|The Maintenance Crew
Platelets are the maintenance crew for the banks of the river traversing through our body. When a blood vessel is cut or ruptures, blood platelets stick to fibers in the damaged area of the vessel, swelling and shooting out tiny spikes to plug the hole. At the same time they signal for help, and other platelets respond by rushing to the site. If the tear is too large to be sealed with platelets, the damaged tissue sends for reinforcements and a liquid protein begins to congeal into long, tough fibers, trapping more platelets in the tangled web until the rent is plugged.
What has prevented some people with more serious injuries from bleeding to death? If all else fails, the arteries shrink, reducing the blood supply to the injured area until sufficient clotting can plug the leak. This process is associated with shock.
Did so elaborate a system of repair and maintenance come about by chance?
Warriors Fight a Never-Ending Battle
The white blood cells consist of three classes of cells and several sub-classes, each with their unique responsibilities. Collectively they fight infections, defend against parasites, take part in hypersensitivity and inflammatory reactions, digest many types of foreign cellular materials and build immunities.
White blood cells, the largest and most numerous of all the blood’s cells yet less than 1% of the blood’s volume, perhaps lead the most active lives. They wind their way through the blood stream, stalking and devouring bacteria, viruses and other tiny invaders-truly, a well-equipped military force against attack.
How are these many cells which make up the blood produced?
Principal Varieties of Blood Cells
|An Unprecedented Manufacturing Facility
The centralized computer, the brain, regulates the manufacturing plant which operates 24 hours a day 7 days a week. As the need rises and falls production increases and decreases to keep a delicate balance of the various cells making up the blood. Let us look at the red blood cell again.
There is an ever-changing need for oxygen as we sleep or exercise, rest or think. The bone marrow will slow or speed production of these red cells to meet the oxygen demand. However, red cells die after about 120 days and must be replaced.
In the time it takes to turn this page, your body will lose about 3 million red cells and your bone marrow will produce the same number. Red blood cell production can be increased up to eight times if the need arises. Greater production of cells means greater demand for oxygen. So great is the demand for oxygen (about 4 gallons per hour) that there are almost countless red blood cells in the body. If stacked, they would reach 31,000 miles high. Yet they are so tiny, it would require 12,500 to measure only one inch high.
There is even a recycling crew.
As red cells age and wear out they are broken down. Nearly all the protein and iron is reused&emdash;a very efficient recycling procedure.
But none of these vehicles could travel on the red river without a pumping station.
Central Pumping Station
Blood circulation depends on a central pumping station that must work 24 hours a day, nonstop. Other muscles soon give out but the heart must keep on working for a lifetime.
A single pause for no more than five minutes would result in death.
The heart, no larger than a fist, is divided into four chambers. The left side receives blood into the top from the lungs and the bottom pumps it to all parts of the body. The right side receives blood into the top and the bottom very gently pumps it into the lungs.
Though its workload is tremendous, rarely does it fail except for some reason other than itself. But if the heart is damaged, by an almost miraculous cooperation many components immediately join forces, converging on the site. If the injury is not too great, white blood cells clear away debris. Within weeks, scar tissue has replaced dead muscle and the heart is patched with stiff, electrically inert fibers. Though the patch cannot contract, the remainder of the heart goes on working, providing life to the body’s cells.
If an artery becomes blocked, alternate routes are established. Small new arteries, or collaterals, grow from branches above the blocked artery and connect to small arteries below the blockage. While this level of protection varies, tests have shown that in some instances normal blood flow to the heart is restored.
Controlled by the brain, the heart rate rises to meet our needs. When we sleep the heart is working at its slowest pace. During exercise it speeds up to supply more blood to the muscles as they burn more fuel. In extreme cases like responding to a sudden threat of death, the heart may speed to a soaring 200 beats per minute, pumping blood with its nutrients so the body and mind can spring into action.
A Thermostat in the Brain
The red river of life plays a vital role in maintaining body temperature within very close tolerances. We would soon die if it rose only 90F above normal. Body temperature is constantly monitored by a thermostat in the brain. Every cell is like a tiny motor burning fuel and giving off heat, which increases with exercise. Infection or exposure to excessive ambient temperature also increases body heat. When our body temperature has raised only a fraction of a degree, our cooling mechanisms turn on-valves open and more blood is directed to the skin, where the heat is rapidly dissipated, aided by the evaporation of sweat.
On the other hand, if body temperature drops, the heart slows, vessels in the skin are constricted and blood is rerouted to deeper paths away from the cold.
Were we to travel from sea level to the top of the highest mountain we would be breathless and dizzy at first because of the lack of oxygen in the thinner air. But our heartbeat would quicken and our bone marrow would increase its production of red blood cells by as much as 50%. Soon we would have adapted to the new environment.
Blood in Scripture
While this red river of life is vital to life, it is only one small part of the extraordinarily complex human body. Is it possible that the human body could be a product of evolution? Surely every thinking individual would have to agree that it is impossible. Surely the Hand that made us is Divine.
Is it any wonder that the Bible uses the term “blood” so many times in reference to life? “…The life of the body is in the blood….” Blood was a symbol of purification: “It is the blood that removes the sins, because it is life” (Lev. 17:11 NCV). If our blood becomes contaminated, we become very sick and perhaps even die. It must always be free of foreign substances. In the same way our inner life must be purified and cleansed from sin.
Jesus used the symbol of the blood as giving eternal life when He said: “My flesh is true food, and my blood is true drink. Those who eat my flesh and drink my blood live in me, and I live in them” (John 6:55-56 NCV). It was not His literal flesh and blood they were to eat but the words He spoke. “Whoever eats this bread will live forever,” He declared (John 6:58 NCV). Some were appalled by this statement, thinking He meant that they must eat His literal flesh and drink His literal blood. So He explained: “It is the Spirit that gives life. The flesh doesn’t give life. The words I told you are spirit, and they give life” (John 6:63 NCV).
Under the law of Moses, blood sacrifices were required. Over and over the people were reminded that the life was in the blood. Jesus explained that the blood represents the words He spoke, the words given Him from the Father.
After having seen how the blood works to supply nutrients and to clean and purify, can’t we better understand the use of it as a symbol of purification from sin in both the Old and New Testaments?
To partake of the eternal blessings, we too, must drink Christ’s blood and eat His flesh, that is, take in His every word and apply it to our lives, until we have become cleansed from sin.
Moody Video, “Red River of Life,” ©1957, 1986 and 1998.