|
|
Between 1999 and 2012, American adults with high total cholesterol decreased from 18.3% to 12.9%
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
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.
It is believed that the Incas used anesthesia. Evidence supports the theory that shamans chewed cocoa leaves and drilled holes into the heads of patients (letting evil spirits escape), spitting into the wounds they made. The mixture of cocaine, saliva, and resin numbed the site enough to allow hours of drilling.
Amoebae are the simplest type of protozoans, and are characterized by a feeding and dividing trophozoite stage that moves by temporary extensions called pseudopodia or false feet.
![A client is having an endoscopy performed by a physician who views the upper gastrointestinal intern](https://biology-forums.com/gallery/47/medium_18099_24_10_12_4_35_00.jpeg)
![In 2008, the U.S. economy suffered a gaping wound as several trillion dollars were ripped out of it.](https://biology-forums.com/gallery/47/medium_262797_12_08_15_1_33_47_22176335.png)