|
|
Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.
About one in five American adults and teenagers have had a genital herpes infection—and most of them don't know it. People with genital herpes have at least twice the risk of becoming infected with HIV if exposed to it than those people who do not have genital herpes.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
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.
Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.
![The functional structure of the peripheral nervous system. (A) Afferent or sensory neurons carry sen](https://biology-forums.com/gallery/47/medium_14755_27_08_12_4_56_12_8219264.jpeg)
![Soothing environments and familiar objects can help reduce behavioral problems with some dementia ...](https://biology-forums.com/gallery/47/medium_665046_09_03_17_7_52_24_267201708.jpeg)