Sugar is harmful, right? While refined sugar does cause inflammation and a range of health problems, the body needs healthy sugars to function. We have long thought that the appendix was a remnant of our evolution: an organ that once served a purpose, but now doesn't do anything other than getting acutely infected, requiring emergency surgery. What a useless little bugger. Upon detecting a pathogen, microphages (or white blood cells) will surround and immobilize it, literally consuming it with their bodies. Antibodies, on the other hand, are the high-powered weaponry made by white blood cells to destroy the invaders ... like a S.W.A.T. team. Between the two, the body is able to fight off infection and prevent the spread of disease. In the animal kingdom, yawning can also be a sign of aggression—particularly amongst apes and monkeys. But with humans, it's usually just because we feel tired. So, if your date is yawning excessively, you might try to change the conversation, suggest a walk outside, or fire up Tinder again. 11. The red color of our blood is caused by the shape of the structure created when iron and oxygen bond with hemoglobin Nearsightedness, or myopia, is caused by a greater curve in the cornea of the eye, or by an elongation of the eyeball. Farsightedness, or hyperopia, is caused by a corneal curve that is too small, or by having a short eyeball. 9. Vaccines safely help the body to recognize and fight off infections later in life

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The innate immune system provides a general defense against harmful germs and substances, so it’s also called the non-specific immune system. It mostly fights using immune cells such as natural killer cells and phagocytes (“eating cells”). The main job of the innate immune system is to fight harmful substances and germs that enter the body, for instance through the skin or digestive system. The cornea (say: KOR-nee-uh), a transparent dome, sits in front of the colored part of the eye. The cornea helps the eye focus as light makes its way through. It is a very important part of the eye, but you can hardly see it because it's made of clear tissue. Like clear glass, the cornea gives your eye a clear window to view the world through. What's the Iris? All the blood leaving the stomach and intestines passes through the liver, where it is processed, broken down, and balanced so that it can be returned to the body fresh and clean. The liver also stores important nutrients and glucose (for energy), metabolizes drugs, synthesizes proteins, and aids in metabolism and detoxification. In other words, our liver is one busy, busy organ! Your heart’s electrical system tells your heart when to contract and when to relax to keep your blood pumping regularly. The instructions to contract and relax are carried by electrical signals. Your health isn’t just dependent on what happens inside your body, but outside it too. Here are some of the ways you can help your body function optimally: Diet ChoicesThe endocrine system produces hormones that regulate metabolism, growth and development, tissue function, sexual reproduction, sleep, and mood. Aim to exercise every day. A long walk is a great way to get your blood and lymph moving and relax your mind. Try different exercises to find something you enjoy. It’s even better if you can find an activity that gets you outside in nature, breathing in clean air and basking under the sun! Sunlight The cardiovascular (or circulatory) system transports blood, oxygen, and nutrients throughout the body. Neither man nor machine can function without fuel! We need a variety of healthy fuel sources to move, think, repair, and regenerate. Your eyes sometimes make more tear fluid than normal to protect themselves. This may have happened to you if you've been poked in the eye, if you've been in a dusty or smoking area, or if you've been near someone who's cutting onions.

15 Human biology basics everyone should know - Brainscape 15 Human biology basics everyone should know - Brainscape

Fat absorbs toxins and keeps them from entering healthy cells. When fats in the cell membrane absorb too many toxins, they are replaced with new, healthy fats. When you think of your body, what do you think of? Your arms, your legs, your brain? What about the 100 trillion cells that work together to make up the big picture of you? What about the outside factors that contribute to your health just as much as the internal factors? To help your body function like a well-oiled machine, be sure to eat a varied, whole-foods diet. Include foods like: Every good design contains a reserve tank, and your body is no different. Whether you’re dealing with an injury, illness, or other medical condition, a reserve tank offers a safety net of life-preserving fuel and nutrients.In the human body, this reserve tank is located in your bones. Here, healthy fats, minerals, and necessary growth factors are stored for a rainy day. When we fall out of homeostasis, we can pull on these resources from the bones. Many scientists today think that yawning is a way to keep our brains alert in times of stress or fatigue, but exactly why that happens or what the yawn does to help our body isn’t 100% clear. Some think it's to oxygenate the brain (through the sudden, deep inhale of breath) or to reboot and re-engage. Yes, I've watched Jurassic Park way too many times.) 4. Our immune system fights off infection mostly through the use of antibodies and microphages These next parts are really cool, but you can't see them with just your own eyes! Doctors use special microscopes to look at these inner parts of the eye, such as the lens. After light enters the pupil, it hits the lens. The lens sits behind the iris and is clear and colorless.

13 Questions About How the Human Body Works Answered 13 Questions About How the Human Body Works Answered

Sometimes someone's eyeball shape makes it difficult for the cornea, lens, and retina to work perfectly as a team. When this happens, some of what the person sees will be out of focus. Alcohol is a diuretic and increases urine production. When you drink alcohol, you need to urinate more often. This causes thirst and dehydration. Lungs The skeletal system provides a strong and durable framework upon which all your meat hangs, while helping to protect your delicate internal organs. You absorb 20 per cent of alcohol into your bloodstream through your stomach and the rest into your bloodstream through your small intestine. When you drink alcohol, your liver oxidises 95 per cent of it. This means your liver converts alcohol into water and carbon monoxide. Your liver can only oxidise one unit of alcohol an hour. Drinking with an empty or full stomachHow do the bones do this? They are made up of minerals like calcium, phosphorus, magnesium, and collagen that can be deployed to create new cells and make sure the body stays in balance. Tears also keep your eye from drying out. Then the fluid drains out of your eye by going into the lacrimal duct (this is also called the tear duct). You can see the opening of your tear duct if you very gently pull down the inside corner of your eye. When you see a tiny little hole, you've found the tear duct.

How does the human body work? - Class 11 - Khan Academy

Fuel is important, but we also need a way to incorporate that fuel into the body. Digestion doesn’t start in the stomach, or even your mouth. Digestion actually starts in your brain!So, there you have 15 extraordinary human biology facts you can use to impress (or gross-out) your next date. Understanding it not only gives you the academic foundation you need to enter a career in medicine or science, but it also helps you interpret and take better care of your body. Your skin consists of three main layers. The outer layer, called the epidermis, contains skin cells, pigment, and proteins. The middle layer, called the dermis, contains blood vessels, nerves, hair follicles, and oil glands, and it provides nutrients to the epidermis. The layer under the dermis, called the subcutaneous layer, contains sweat glands, some hair follicles, blood vessels, and fat. Each layer also contains connective tissue with collagen fibers to give support and elastin fibers to provide flexibility and strength. Cells in the deepest layer of your epidermis are constantly dividing to make new cells, providing your skin with a durable overcoat, which protects deeper cells from damage, infection, and dryness. Cells on the surface of your epidermis flake off and are continuously replaced with new ones, so that about every 30 days your body produces a whole new set of skin. A human body sheds about 600,000 particles of skin every hour—that’s about 1.5 pounds (0.68 kilogram) a year. By age 70, an average human will have lost 105 pounds (47.6 kilograms) of skin. You may not be sober or safe to drive a vehicle. The legal alcohol limit for driving measures the amount of alcohol in your breath, blood or urine. Kidneys A moderate sunburn can do long-term damage to the blood vessels in your skin, making it more difficult for the affected areas to heal and stay healthy. It can actually take four to fifteen months for these capillaries and small arteries and veins to return to a normal condition. 15. All body parts can repair themselves (except teeth) Well, there are many different kinds of vaccines but, in the case of those we are most recently familiar with—COVID-19 vaccines—they either work by: