|
|
Only one in 10 cancer deaths is caused by the primary tumor. The vast majority of cancer mortality is caused by cells breaking away from the main tumor and metastasizing to other parts of the body, such as the brain, bones, or liver.
In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.
People about to have surgery must tell their health care providers about all supplements they take.
Elderly adults are living longer, and causes of death are shifting. At the same time, autopsy rates are at or near their lowest in history.
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.
![Several species of squirrels have melanistic phases. In large parts of United States and Canada, the](https://biology-forums.com/gallery/47/medium_12359_08_06_12_5_35_15.jpeg)
![To keep the foot under the center of gravity, the biped’s femur is angled from hip to knee. The quad](https://biology-forums.com/gallery/47/medium_295860_21_02_15_1_23_43_20669384.jpeg)