Facts About Humans

Brain structure

The brain is made up of water, protein, carbohydrates, salts, and fat. 

The brain is soft and gel-like, similar to tofu. 

The brain's outer layer is called the cortex, which is made up of millions of cells that send messages to other parts of the brain.

Over one-fourth of the oxygen consumed by the human body goes to the brain.

An adult's brain weighs about three pounds (1.5 kg). Even though it only makes up 2% of the body's weight, it consumes about 20% of its energy.

Your brain would lay flat, the size of a pillowcase, if all the wrinkles were removed.

Your brain generates enough electricity while you are awake to illuminate a room.

Your brain's left side controls your right side, while its right side controls your left side of the body.

A human brain can store more data than 4 terabytes.

The brain's nerve impulse travels at a rate of 100 m/s.

In a single day, a single human brain produces more electrical impulses than all the phones combined in the globe.

An individual remembers, on average, 150 trillion bits of information by the time they pass away.

According to a 2012 study that was published in the Proceedings of the National Academy of Sciences, the human brain has roughly 86 billion nerve cells (neurons), sometimes known as "gray matter". The number of non-neuronal cells in the brain is likewise similar, including the oligodendrocytes that surround the axons of neurons with myelin sheaths.

The ability for a person to carry out daily activities normally depends on a type of tissue called gray matter in the brain and spinal cord. It has densely packed dendrites, axon terminals, and neuronal bodies. The surface of the human brain is covered in many gyri and sulci. The gray matter, or neurons, that make up this thin strip of sulci and gyri that covers the surface of the brain.

The water content of the brain is roughly 75%. So according to this, dehydration can harm the brain's processes even in little doses.

In the first year of life, the human brain will triple in size. Up until you turn roughly 18 years old, it keeps expanding.

The muscles and nerves in your neck and head, along with a chemical reaction in your brain, are what give you a headache.

Cholesterol is essential for learning and memory. However, the effects of high cholesterol vary based on your age and other circumstances.

Dreams are thought to be the result of a combination of imagination, physiological elements, and neurological components. They demonstrate that your brain is active even while you are sleeping.

Phantom limb pain syndrome occurs when your central nervous system, which includes your brain, continues to feel the pain of an amputated limb.

As we become older, the human brain shrinks. This frequently occurs after reaching middle age.

Among the signs of alcohol's effects on the brain are slurred speech, blurred vision, and an unsteady walk. These usually go once you are sober again. Nonetheless, there is proof that prolonged heavy drinking can cause irreversible brain damage, and that this effect persists after you stop drinking. Long-term effects include memory issues and possibly cognitive decline.

Eyewitness accounts of criminal suspects are often only 50% accurate since it is hard for the brain to remember the specifics of someone you do not know. Additionally, traumatic events can affect the brain's capacity to remember details.

Computer or video games may help in cognitive enhancement. However, additional research is needed to determine how much they benefit and what types of games help.

The brain is incapable of feeling pain. It interprets pain signals but does not experience pain.

Sphenopalatine ganglioneuralgia is the medical term for brain freeze. It occurs when you consume cold foods or beverages. It cools the blood vessels and arteries in the back of the throat, particularly those that transport blood to the brain. These constrict in the cold and reopen in the warm, causing the soreness in your forehead.

By your late twenties, the human brain begins to lose certain memory and cognitive abilities.

An average person's eye blinks 20 times each minute. Over ten million times a year, that is.

The lifespan of an eyelash is roughly 150 days before it falls out.

The only organ in the body that does not have a blood supply and instead obtains its oxygen from the atmosphere is the cornea.

The human eye has around 576 megapixels in camera terminology.

The convex eye lens creates an inverted image on our retina, which our brain is wired to erect. The world appears to be upside down to a newborn until the brain begins to turn it around.

At least 20 quadrillion miles are visible to us.

Blue-eyed people are more sensitive to pain than other people.

The human eye can differentiate between 10 million different color tones.

Every person with blue eyes is thought to have a common ancestor with every other blue-eyed person on the planet.

The 20-20-20 rule can be beneficial to your eyes. This rule applies when you work for long periods of time in front of a computer. The rule states that every twenty minutes, you should glance at anything twenty feet away for twenty seconds. In general, using this strategy helps people avoid eye strain. It's also a good reminder to take a break every now and then.

According to studies, tying a tie excessively tightly can raise the risk of glaucoma in men. Too tight a knot can raise ocular pressure, which is the most common cause of this condition.

During a vision test, doctors can detect health issues such as diabetes and high blood pressure. The doctor can tell by looking at the blood vessels in your retina. Our retina is thought to be a reliable indicator of the health of our body's blood vessels.

Scientists discovered that having two eyeballs allows us to constantly compare two images at the same time. These images allow us to calculate the distance between us and an object.

Smoking can impair your capacity to perceive objects in the dark. This is due to the fact that smoking has a negative impact on your night vision and can cause it to deteriorate.

According to research, the human eye contains around two million functional elements that allow it to function.

One eye is always more powerful than the other. This is also known as anisometropia. This causes our brains to prefer one eye over the other in order to convey superior images and information.

Human eye muscles are around 100 times stronger than they need to be to execute their duties.

One of the most common causes of eye injury is cosmetics. Using eye makeup, particularly mascara and eyeliner, is reported to be one of the most common causes of eye injuries among women. 

Contact lenses cannot be lost in your eyes. Because of the structure of the human eye, this is not conceivable. Because of the muscles that protect the eyeball, nothing can get into the rear of the eye. If you "lose" your contact lenses, simply apply contact lens solutions and gently massage your eyeball while closing your eyes.

Human ears are constantly expanding.

The inner ear's primary tasks are balance and hearing. Therefore, an illness that impacts one system also affects the other. For instance, low-frequency hearing loss and vertigo are symptoms of Meniere's illness.

The innermost, pea-sized component of the ear is called the cochlea. It resembles a snail's shell and, if unravelled, would resemble a 31.5 mm long miniature tube.

The stapes is the smallest bone in the human body, and the middle ear has the smallest bones overall. These three tiny bones, which can all fit on a penny, are responsible for transferring sound to the inner ear.

Frequencies as high as 20,000Hz and as low as 20Hz are audible to humans.

Human ears continue to work while we sleep. Although they pick up noises, the brain muffles them.

Though they have limitations, human ears can generally perceive noises. In the ear, sounds that are louder than a specific frequency level register as ringing or buzzing (this is distinct from tinnitus, which also registers as ringing or buzzing).

Human ears can clean themselves. The microscopic hairs known as cilia and the pores in the ear canal create cerumen (earwax), which is then naturally pushed out of the ear canal along with the debris it catches. The majority of people consider earwax to be "gross," although it shields the ear from friction, dirt, and debris. It doesn't need cleaning out until you have a lot of it.

The sensory neurons that control hearing are known as hair cells. The cochlea is where they are located. Hearing loss occurs when these cells are harmed or eliminated due to ageing, excessive loud exposure, ototoxic chemicals, or inadequate blood supply. Unfortunately, because these hair cells do not regrow, the majority of hearing loss is permanent.

Three tiny loops, referred to as semi-circular canals, are located above the cochlea in the inner ear. They have thousands of tiny hairs and are liquid-filled. The fluid in the semi-circular canals moves when your head moves, which aids in maintaining your balance while you're moving.

Because the nerves known as the Chorda Tympani pass through the ear and link the taste receptors on the front of your tongue to the brain, injury to your ears may affect how you perceive flavours. After ear surgery, some patients may notice a change in their perception of taste. This does not imply that a hearing impairment causes a person to lose their capacity to taste.

Children are more likely than adults to suffer ear infections because of their immature immune systems and different shaped Eustachian tubes.

Over the age of 65, about one out of every three adults has hearing loss. It implies that 165 million people globally have hearing loss in varying degrees.

High volume music playback on a smartphone while using headphones or earphones over an extended period of time can harm your hearing permanently.

The heart is the only muscle that never gets tired.

Your heart will have beat almost 2.5 billion times if you live to be 70 years old!

If you survive past the age of 30, your heart will beat more than a billion times each year and approximately 100,000 times every day.

Your heart will beat in time with the music as you listen to it.

An adult human heart beats on average 75 times in a minute.

A human heart can pump enough blood in a year to fill an Olympic-sized swimming pool.

The human heart pumps 48 million gallons (182 million liters) of blood in his life.

Male and female hearts beat at different rates. Female heart beats faster.

The rhythm of your heart is controlled by an electrical system. The cardiac conduction system is what it's called.

Even when the heart is detached from the body, it can continue to beat.

In 1893, the first open-heart surgery was performed. Daniel Hale Williams, one of the few black cardiologists in the United States at the time, conducted the procedure.

In 1958, the first implanted pacemaker was utilized. Arne Larsson, the pacemaker recipient, lived longer than the surgeon who put it. Larsson died at the age of 86 from a condition unrelated to his heart.

The youngest person who received heart surgery was only a minute old. She had a cardiac problem, which kills many babies. Her surgery was successful, but she will require a heart transplant in the future.

The remains of a 3,500-year-old Egyptian mummy were discovered to contain the earliest documented case of heart disease.

The majority of heart attacks occur on Mondays.

The sound of your heart pounding is created by the heart valves opening and shutting.

Death from a broken heart, also known as broken heart syndrome, is possible but highly uncommon.

Laughter is excellent for the heart. It relieves stress and strengthens your immune system.

The famous heart shape as a sign of love is considered to have originated from the silphium plant, which was once used as a form of birth control.

The average person's fist is about the same size as their heart.

The surface area of an adult's lungs is about 70 square meters.

Your left and right lungs differ slightly from one another. While the lung on your right side of the body is split into three lobes, the lung on your left side is divided into two lobes. Additionally, your left lung is a little bit smaller, making room for your heart.

Over 300 million alveoli and nearly 1,500 miles of airways make up a human lung.

The lungs are the most important organs of the respiratory system. Every minute, the average person breathes around 13 quarts of air.

The only organs in the human body that can float on water are the lungs.

A healthy man's lung capacity is estimated to be 6000 ml.

Regular physical activity can enhance lung capacity, which aids in the reduction of lung-related illnesses as well as the easier and faster passage of air into the body via the lungs.

Coughing may not usually indicate an issue with your lungs. Coughing roughly 10 times a day is extremely normal for the average person, regardless of the cause.

Tobacco use is the leading cause of lung cancer and other lung-related diseases. Passive smoking raises the chances of developing lung cancer, coronary artery disease, and stroke.

The right lung has three lobes and the left lung has only two. This leads to the difference in size between your lungs.

The brain is in charge of your lungs. Because your brain controls your lungs how much to inhale or exhale, you may notice variations in your breathing without intending to.

It is possible to live a normal life with only one lung. You may experience difficulty while exercising, but as long as you do not overexert yourself, the effect will be minimal.

When you breathe, your body only consumes 5% of the oxygen that you inhale. The rest is exhaled, and the cycle begins again.

Your lungs serve various functions besides breathing. Breathing allows you to remove around 70% of waste from your lungs, which is beneficial for those who are concerned about breathing and retaining bad quality air.

Your lungs are linked in the rear to your spinal cord and in the front to your chest bone. For protection, they are stored within your rib cage.

While your lungs may appear to be another enigmatic organ in your body that you never see, your mouth is closely related to your lungs. This is accomplished by connecting your windpipe and oesophagus.

A baby's lungs are filled with fluid when in the womb. A baby's first breath takes about 10 seconds after birth as a result of the change in environment.

Aside from breathing, the lungs also play an important role in communication. The larynx, or voice box, is placed above the wind pipe, so air from the lungs is forced through the voice box and converted to sound.

Breathing deeply into your lungs can help you relax more and relieve stress. Breathing is beneficial in exercises such as yoga and meditation.

Your lungs have their own defence mechanisms to protect your body as much as possible from pollution and contaminants. The lungs contain cells that create mucus to protect against dust and dirt.

Even if you don't smoke and exercise regularly to be healthy, your lungs can still suffer if you live or work in an area with high pollution.

The kidney's filtering cells, called nephrons, remove blood from the body in about 45 minutes and discharge around six cups (or 2000 ml) of urine daily to the bladder.

The blood flow in the kidneys is greater than that in the heart, liver, and brain.

Every minute, the kidneys filter about a half cup of blood, eliminating wastes and excess water to produce urine.

The kidneys are two bean-shaped organs found right below the rib cage, one on each side of the spine, each roughly the size of a hand.

The kidneys reabsorb and redistribute 99% of the blood volume throughout the body, with the remaining 1% becoming urine.

The kidneys are often asymmetrical, with the left kidney somewhat larger and higher than the right.

Keep hydrated: the most common cause of kidney stones is a lack of fluids, particularly water.

A kidney stone the size of a coconut was the largest ever documented. It weighed in at 2.5 pounds (1.1 kilogrammes).

You do not require both kidneys. One-half of a kidney can do the work of two, and 75% of one kidney can comfortably support life.

If a child is born without one of his or her kidneys, the other will grow and weigh the same as two kidneys together.

Our filtration system should be grateful to these tiny filtering units known as nephrons. To keep you alive, they remove toxic chemicals and extra fluids from your blood.

Your body has approximately 1.15 million nephrons. They are approximately 5 miles (8 km) long when stretched end to end.

Kidneys can also activate vitamin D in your body as a final resort. If your skin cells are unable to absorb vitamin D from the sun, your liver takes over. And if your liver is unable to generate vitamin D, your kidneys will.

Every day, the kidneys also pump approximately 400 litres of blood.

Yuri Voronoy performed the first human kidney transplant in Ukraine in 1933. Unfortunately, it did not succeed.

In 1954, Joseph E. Smith and his team performed the first successful kidney transplant in Boston.