|
|
Many of the drugs used by neuroscientists are derived from toxic plants and venomous animals (such as snakes, spiders, snails, and puffer fish).
On average, the stomach produces 2 L of hydrochloric acid per day.
Prostaglandins were first isolated from human semen in Sweden in the 1930s. They were so named because the researcher thought that they came from the prostate gland. In fact, prostaglandins exist and are synthesized in almost every cell of the body.
Approximately 15–25% of recognized pregnancies end in miscarriage. However, many miscarriages often occur before a woman even knows she is pregnant.
Astigmatism is the most common vision problem. It may accompany nearsightedness or farsightedness. It is usually caused by an irregularly shaped cornea, but sometimes it is the result of an irregularly shaped lens. Either type can be corrected by eyeglasses, contact lenses, or refractive surgery.
![H. erectus migrated out of Africa beginning about 1.8 million years ago and is first known from Geor](https://biology-forums.com/gallery/47/medium_275510_22_02_15_5_56_58_207731480.jpeg)
![This portrait of Thomas Jefferson is considered an accurate likeness, painted when he was thirty-sev](https://biology-forums.com/gallery/47/medium_374628_16_08_15_9_52_08_22257994.jpeg)