The Bible says, “Then the Lord God formed a man from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being” (Genesis 2:7). Among all things that God made, only humans have a soul. This is a mystery. The human body is also full of mysteries. Our bodies are comprised of skin, flesh, bones, blood, and organs. And it is amazing how our brain, heart, and other organs function! Moreover, there are interesting biological numbers associated with our amazing bodies.

Interesting Biological Numbers

1. Brain

The brain of an adult weighs 1.4 to 1.5 kilograms (kg), which accounts for 85% of the brain’s total weight. There are over 10 million wire-like nerves connected to our brain. If every single nerve were connected, it would be 300,000 kilometers (km) long—like a very long electric wire in the human body. Among the trillion brain cells, perhaps 100 billion of them are active nerve cells. Every nerve cell can make up to 20,000 connections with other cells. Some experts point out that the number of connections made by nerve cells could be greater than the number of atoms in the universe.

There are around 14 billion nerve cells in the brain. The diameter of each nerve cell is only one hundred thousandth of a centimeter (cm). The volume is only one ten millionth of a cubic cm (cm3).

There are around one billion sulci in the cerebral cortex. If we spread them out, the area is over 2,000 square cm. With blood vessels crisscrossing in the human brain, the total length of blood vessels is over 120,000 meters (m). The brain needs a huge volume of blood. Every minute, over 700 milliliters (ml) of blood flow through the brain, accounting for 1/6 of the blood being pumped out of the heart.

The brain can hold a huge amount of information, up to one quadrillion bits (unit of information), which is equivalent to a billion books. For each cm3 of the brain, one trillion bits of information can be stored. Within one second, over 100,000 different chemical reactions are happening in our brain. These chemical reactions produce thoughts, emotions, and actions in us.

2. Eyes

The eyes are called the windows of the soul. One blink takes around 1/24 second. Every day, it retains over 50,000 different images. The eyes of a normal person can see and discern 7 million colors of different shades.

Humans have sharp eyes. On a moonless night, standing on a high point, we can see the light of a burning match from 80 km away.

3. Nose, Tongue, Throat, Trachea

The two nasal cavities are separated by the nasal septum. Nasal hair usually grows in the nostrils, functioning as a filter for the dust and impurities in the air. The nasal cavities are lined with a mucous membrane, which helps to humidify the air we breathe in and trap debris. In the back of the nasal cavities are the sinuses. Under the cranium on the sides of the nose are olfactory (sense of smell) nerves. The nasal cavities are connected to the throat, share the passageway with the digestive system, then branch into the respiratory system and the lungs.

On the surface of the tongue, there are 9,000 to 10,000 taste buds, capable of tasting four flavors: the front of the tongue tastes sweetness and saltiness, while the sides discern sourness, and the back part picks up bitterness.

The throat is of utmost importance in the human body. The main functions of the pharynx include swallowing, breathing, voice production, and regulation of middle ear pressure. The tonsils in the pharynx have the functions of phagocytosis of bacteria, production of antibodies, and production of lymphocytes. They are the guards of the respiratory tract. When we breathe normally, the air must pass through the larynx. The larynx is an important organ in voice production and also warms and humidifies the air we breathe in. The larynx is also involved in breath-holding and responds to cardiovascular reflex.

The trachea is the tube between the larynx and the bronchi. Aside from being an airway, it also provides protection against—and removal of—foreign objects, as well as regulating air temperature and humidity. Every day, around 14 cubic meters (m3) of air enter our body through the trachea, which cleans, humidifies, and warms the incoming air. This warm body of air can fill up over 300 huge balloons.

4. Ears

Humans can listen to beautiful music, discern in great detail different sounds—such as that of streams, rivers, thunder, and rain—as well as the singing and laughter of men and women—the old and the young—and distinguish the sound quality and timbre of various musical instruments. All of these are because God gave us a pair of intricately designed ears. The range of sound humans can hear lies between 20 to 20,000 Hertz (Hz, frequency unit). The sound beyond this range is called ultrasound. For example, bats can hear high-frequency sounds at 120,000 Hz, while cats can hear the high-frequency sounds of mice. It is a good thing that we cannot hear high-frequency sounds, so that we can enjoy quietness—deaf to the nuisance of a lot of noises. The cochlea analyzes pitch through the basilar membrane, which sits outside the screw plate and is only around 30 millimeters (mm) long, yet contains 2,000 to 3,000 horizontal fibers, which are used to respond to sounds. They are arranged in a way likethat of string instruments, that is, from short to long. The widest part is around 0.5 mm on the top of the cochlea, which is sensitive to low frequencies, while the narrowest part is around 0.04 mm at the base of the cochlea and is sensitive to high frequencies. The intricate resonance design inside this tiny cochlea allows us to hear all sorts of beautiful music made by instruments and the sounds of nature. How can we not praise God for His wondrous creation?

5. Heart

The heart of an adult weighs around 300 grams (g). It is of paramount function. For example, when a person is in a resting state, the heart beats around 70 times per minute, pumping 70 ml of blood each time. So, for each minute, around 5 liters of blood would be pumped. The heartbeat is formed by the rhythmic contraction and relaxation of the cardiac muscles. When the cardiac muscles contract, blood is pumped into the arteries and flows through the whole body. When the cardiac muscles relax, blood flows back into the heart through the veins. So, the beating of the heart promotes the flow of blood. It is the engine in blood transport. The function of the heart is to promote blood flow, providing enough blood to organs and tissues to provide oxygen and various nutrients (such as water, inorganic salts, glucose, protein, and various water-soluble vitamins) and to remove the end products of metabolism (such as carbon dioxide, urea, and uric acid), so that cells maintain normal metabolism and function. Various endocrine hormones and other humoral factors must be transported to target cells through blood circulation to realize the regulation of body fluids and to maintain relatively constant internal body conditions. The defense mechanism and the relatively constant regulation of body temperature are realized through the non-stop circulation of blood in the vessels, and this circulation is realized through the pumping action of the heart.

6. Lungs

The lungs are formed of numerous tiny alveoli. Slightly hemispherical, with surfaces in contact with air, an alveolus is the smallest respiratory unit in the lungs. The absorption area of the lungs is 120,000 cm3, as large as the floor area of a small house. When the chest cavity is expanded and at its highest capacity, the lungs of an adult can hold 4.5 kg of air. The internal surface area of the lungs is around 50 times the skin surface area.

7. Liver

The human liver only weighs 1 to 1.5 kg. Protected by the ribs, located on the top right of the abdomen, the liver is the huge “chemical plant” of the human body, responsible for over 500 kinds of the most arduous and complicated tasks to maintain life. A big part of human metabolism involves biochemical changes, inseparable from catalysts. There are over 1,000 proteins called “enzymes” in the liver, constituting various efficient catalysts, and controlling the progress of chemical reactions.

8. Red Blood Cells and White Blood Cells

The red blood cells (RBCs) mainly transport oxygen to cells in the body and bring carbon dioxide to the lungs. The RBCs have a bioconcave shape, where the sides of the cell curve inwards. This shape helps the RBCs to flow past narrow blood vessels and bring oxygen to organs and tissues. RBCs live for around four months. During this period, they travel around 1,609 km in our bodies. The white blood cells (WBCs) form a huge blood cell family. Despite having an array of shapes, structures, and biological functions, they are not isolated and play a synergistic role in the protection, immunity, and wound healing of the body.

9. Bones

The bones support the human body and are a part of its movement system. An adult has 206 bones, and the bones are usually connected by joints and ligaments.

10. Muscles, Skin

Muscle cells have contractile fibers that move between cells and change the size of the cells. There are three types of muscles: skeletal muscle, cardiac muscle, and smooth muscle. All of them function to generate force and facilitate movement. The contraction of cardiac and smooth muscles is controlled subconsciously, as they are necessary for survival—such as the contraction of the heart or gastrointestinal peristalsis. The voluntary contraction of the skeletal muscles is for moving the body and can be precisely controlled, such as the tiny movement of the eye or the general movement of thigh quadriceps. When we smile, 17 facial muscles are engaged. When we frown, 43 facial muscles are engaged.

Human skin accounts for around 1/20 of our body weight. The skin of our palms and feet are around 4 mm thick, while that of our eyes and ears are only 0.5 mm thick. The thinnest part of the skin is 0.5 mm thick, while the thickest part is around 4 to 5 mm thick. When spread out, the skin of an adult is around 2 m3. For each m3 of skin, there are 14,000 pores. If we connect these pores one by one, we will get a small water pipe that is 60 m long. The total area of a person’s skin is 1.8 m3. Assuming each cm3 of skin can endure 1 kg of air pressure, the skin of the entire body could at most bear 18,000 kg of pressure, which is equivalent to a person shouldering the weight of 9 to 10 big cars without breaking a sweat. In a person’s lifetime, the average total weight of the shed skin is over 227 kg.

The Spiritual Meaning Within

1. The mysteries of the human body are a part of the mysteries of God.

All of God’s works are a mystery to humans who are finite and limited. “As you do not know the path of the wind, or how the body is formed in a mother’s womb, so you cannot understand the work of God, the Maker of all things” (Ecclesiastes 11:5). We cannot be blind to the mysteries in our bodies and in this world. Only our wondrous God could do such wondrous deeds. Scripture states that, “For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse” (Romans 1:20). The world and everything in it, including humans, are the work of God and not the product of evolution.

2. God’s Wondrous Creations are for His Glory.

The Bible tells us, “All the nations you have made will come and worship before you, Lord; they will bring glory to your name” (Psalm 86:9). The Psalmist exults, “I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well” (Psalm 139:14).

*Qizhi Yan is a retired senior lecturer who has edited a variety of books such as The Concise Bible Dictionary. This story was first published in Chinese Today, Issue No. 725 (Sept 2022) and was translated into English by Kiara Ngai.