I learned this today. Our skin can allow sweat out, but it doesn’t let water in thanks to a thin layer of fat between the outermost layers of skin cells. The skin is said to be the largest organ in the human body. Actually, by surface area, it is the second largest because the inside […]
#82 Why is skin waterproof? Read More »
I learned this today. Dogs can probably smell cancer in people. Dogs have a phenomenal sense of smell. They have 300 million olfactory receptors in their noses. We have about 6 million. On top of this, the part of their brain that is devoted to analyzing smells is about 40 times larger than ours. It
#79 Can dogs smell cancer? Read More »
I learned this today. We feel pain when we touch something very cold or very hot because of thermoreceptors in our skin that are activated by different proteins. Humans are able to withstand a fairly large range of temperatures, but we have to wear clothes to do this. Ancient humans started wearing clothes about 780,000
#63 Why do we feel pain when we touch cold or hot things? Read More »
I learned this today. The tallest a human could potentially grow is about 9 feet, 274cm. Humans grow because of a growth hormone called somatropin. It stimulates growth by telling cells to reproduce. It is released by the pituitary gland. It reacts with a specific receptor on the surface of cells, and it stimulates cell
#58 How tall could a human grow? Read More »
I learned this today. White blood cells kill invading bacteria, germs, and viruses in your body by eating them. White blood cells are produced by bone marrow. They are produced by hematopoietic stem cells, and they are stored within the bone marrow or lymph tissue until they are needed. They are also called leukocytes. When
#50 How do white blood cells kill pathogens? Read More »
I learned this today. Slime mold is a collection of single-celled organisms that can move, function, and “think” as a single organism. Slime molds are eukaryotes: cells that have a nucleus enclosed within a nuclear envelope. They usually live as single cells, but they can join together with other cells to create a multicellular organism.
#45 Why is slime mold so awesome? Read More »
I learned this today. Cigarettes are addictive because the nicotine they contain is a highly addictive chemical. Nicotine is a naturally occurring chemical that is produced by plants. It is produced by many different types of plants: nightshade, tobacco, the coca plant, tomato, potato, eggplant, and green pepper. The concentrations differ depending on the plant.
#41 Why do we become addicted to nicotine? Read More »
I learned this today. Unlike when skin heals, bones usually heal without a scar. When you cut yourself, your body’s primary goal is to replace the skin as quickly as possible to keep infection out and your blood in. When it does this, it leaves a scar because it builds the new skin so quickly.
#39 How do broken bones heal? Read More »
I learned this today. The most common kidney stones are caused when there are more minerals in the blood than the kidneys can reabsorb. Most people have two kidneys. The kidneys have three jobs that they do for us. Their first job is to filter waste products out of the blood. Together, they filter 200
#36 How do kidney stones form? Read More »
I learned this today. Scars are left after a wound because the body is trying to put a protective covering over the wound as fast as it can. When you cut your skin, if it is more than a surface graze, you start to bleed. The first thing that happens is your blood clots. There
#32 Why do wounds heal with scars? Read More »
