|
|
There are 20 feet of blood vessels in each square inch of human skin.
About 60% of newborn infants in the United States are jaundiced; that is, they look yellow. Kernicterus is a form of brain damage caused by excessive jaundice. When babies begin to be affected by excessive jaundice and begin to have brain damage, they become excessively lethargic.
Hyperthyroidism leads to an increased rate of metabolism and affects about 1% of women but only 0.1% of men. For most people, this increased metabolic rate causes the thyroid gland to become enlarged (known as a goiter).
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.
The average human gut is home to perhaps 500 to 1,000 different species of bacteria.
![Lake position in the landscape and proportion of water received as groundwater (data from Webster et](https://biology-forums.com/gallery/47/medium_33_19_02_12_5_42_32_20651521.jpeg)
![Glioma. (a) Illustration of a large glioma (colored area) within the left cerebral hemisphere in a s](https://biology-forums.com/gallery/47/medium_14755_14_10_12_6_48_57_94081413.jpeg)