Did you know?
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
Did you know?
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.
Did you know?
Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.
Did you know?
Human neurons are so small that they require a microscope in order to be seen. However, some neurons can be up to 3 feet long, such as those that extend from the spinal cord to the toes.
Did you know?
The average office desk has 400 times more bacteria on it than a toilet.