Most people think humans only have five senses: taste, touch, smell, sight, and hearing. But that’s not entirely true! Scientists say we have between 9 and 20 senses. Some of these include thermoception (the sense of temperature) and equilibrioception (the sense of balance). There’s even a sense of time, although not everyone seems to have that one!
Did you know there are over 30 known blood group systems, not just the eight we usually hear about? Our bodies are full of surprises. For example, for every pound of fat you gain, your body creates one mile of new blood vessels to supply oxygen and nutrients.
Your stomach produces a new lining every six days to avoid digesting itself. Nerve cells in your body can transmit 1,000 impulses per second, traveling at speeds between 1 and 268 miles per hour!
Believe it or not, your body emits visible light! You’re the brightest at 4 PM, but this glow is 1,000 times less intense than what our eyes can see. Sweat is mostly water mixed with proteins, sugars, and trace metals like copper and zinc. The sodium in sweat makes it taste salty, and the more salt you eat, the saltier your sweat becomes.
If you walked at two miles per hour, you’d need to walk for 20 hours straight to lose one pound. Your brain gets three times bigger in the first year of life and reaches full maturity at 25. It’s 60% fat and generates about 23 watts of electrical power, enough to power a small light bulb!
Humans can’t truly multitask. Our brains switch between tasks, which can lead to mistakes. If you need to focus, try chewing gum. It can help you concentrate for about 20 minutes.
Embryos develop fingerprints at three months. Our bones are four times harder than concrete, and the femur is the strongest bone, able to support 30 times the weight of an adult. Sunburn is a result of radiation exposure when our body’s defenses get overwhelmed by UV rays.
Goosebumps are an evolutionary reflex from our ancestors. They made their hair stand up to look scarier to predators. Your body produces one to three pints of saliva daily, which helps digest food and fight infections.
The average person has about 150,000 hairs on their head, each growing about half an inch per month. If combined, the growth would measure 10 miles in a year. A single strand of hair can hold the weight of an apple, and all your hair together could support two elephants!
The beating sound of your heart is the clap of valve leaflets opening and closing. Your corneas are the only part of your body that doesn’t get blood; they get oxygen directly from the air.
Your brain has 100 billion neurons and is 73% water. If it loses even 2% of its liquid, you start to feel tired, and your memory and mood can suffer. The earliest known person with blue eyes lived 7,000 years ago in the Stone Age.
Your right kidney is smaller and sits lower than your left to make room for your liver. Your brain ensures you don’t drink too much or too little water by sending signals to stop drinking after you’ve had enough.
Your eyes can see something for just 13 milliseconds, and your brain will process the image. The average blink lasts 100 to 400 milliseconds. The tongue, made of eight interwoven muscles, never gets tired because it’s not connected to bone at both ends.
Your skin is your largest organ, covering about 22 square feet and accounting for 16% of your body weight. If you typed 60 words per minute for 8 hours a day, it would take 50 years to type the human genome!
Your body has 78 organs, but only five are essential for survival: the brain, liver, kidneys, lungs, and heart. At night, when it’s quiet, you might hear phantom sounds like ringing or buzzing, which don’t have an external source.
Women have more taste buds than men, making them more likely to be “super tasters.” Left-handed people often chew on the left side, while right-handed people chew on the right. Even if your fingerprints are damaged, they’ll grow back in the same unique pattern.
Explore the lesser-known senses beyond the traditional five. Create a sensory station where you can experience thermoception by feeling objects at different temperatures and equilibrioception by trying balance exercises. Reflect on how these senses help you interact with the world.
Investigate the various blood group systems beyond the common ABO and Rh systems. Create a poster or presentation to share your findings with the class, highlighting the diversity and importance of these blood groups in medicine and biology.
Conduct an experiment to understand how your body emits light. Use a dark room and a camera with a long exposure setting to try capturing the faint glow. Discuss why this light is not visible to the naked eye and what it reveals about human biology.
Test your brain’s multitasking abilities by attempting to perform two tasks simultaneously, like reading and listening to music. Record your observations and discuss why multitasking can lead to mistakes, using the information about brain function from the article.
Learn about the strength of bones by comparing them to materials like concrete. Use objects of different hardness to simulate bone strength and discuss why bones are essential for supporting the body, referencing the femur’s ability to support weight.
Senses – Biological systems that allow organisms to perceive and respond to stimuli in their environment. – Humans have five main senses: sight, hearing, taste, touch, and smell, which help them interact with the world around them.
Blood – The fluid that circulates in the arteries and veins of humans and other vertebrates, carrying oxygen and nutrients to the cells and removing waste products. – Blood is pumped by the heart and travels through the body, delivering essential substances to cells and tissues.
Body – The physical structure of a person or an organism, consisting of bones, flesh, and organs. – The human body is made up of various systems that work together to maintain health and function.
Sweat – A liquid produced by glands in the skin that helps regulate body temperature by evaporating and cooling the skin. – When you exercise, your body produces sweat to help cool you down.
Brain – The organ in the head that controls the body’s functions, thoughts, and emotions by processing information from the senses. – The brain is the control center of the nervous system, responsible for interpreting sensory information and coordinating responses.
Neurons – Specialized cells in the nervous system that transmit information through electrical and chemical signals. – Neurons communicate with each other to send messages from the brain to different parts of the body.
Organs – Structures made up of different tissues that perform specific functions necessary for the body’s survival. – The heart, lungs, and liver are examples of vital organs that keep the body functioning properly.
Heart – A muscular organ that pumps blood throughout the body via the circulatory system. – The heart beats continuously to ensure that oxygen-rich blood reaches all parts of the body.
Temperature – A measure of the warmth or coldness of an environment or body, often regulated by physiological processes. – The human body maintains a stable internal temperature of around 37°C (98.6°F) to function optimally.
Balance – The ability to maintain a stable position or equilibrium, often involving the coordination of sensory and motor systems. – The inner ear plays a crucial role in helping the body maintain balance and orientation.
