Ask unlimited questions for free
The first-known contraceptive was crocodile dung, used in Egypt in 2000 BC. Condoms were also reportedly used, made of animal bladders or intestines.
The horizontal fraction bar was introduced by the Arabs.
Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.
The familiar sounds of your heart are made by the heart's valves as they open and close.
The term pharmacology is derived from the Greek words pharmakon("claim, medicine, poison, or remedy") and logos ("study").
For a complete list of videos, visit our video library