|
|
When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.
Symptoms of kidney problems include a loss of appetite, back pain (which may be sudden and intense), chills, abdominal pain, fluid retention, nausea, the urge to urinate, vomiting, and fever.
Before a vaccine is licensed in the USA, the Food and Drug Administration (FDA) reviews it for safety and effectiveness. The CDC then reviews all studies again, as well as the American Academy of Pediatrics and the American Academy of Family Physicians. Every lot of vaccine is tested before administration to the public, and the FDA regularly inspects vaccine manufacturers' facilities.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.
According to research, pregnant women tend to eat more if carrying a baby boy. Male fetuses may secrete a chemical that stimulates their mothers to step up her energy intake.
![In 2008, the U.S. economy suffered a gaping wound as several trillion dollars were ripped out of it.](https://biology-forums.com/gallery/47/medium_262797_12_08_15_1_33_47_22176335.png)
![If you want to show differences between items at the same time, a bar graph is more effective than a](https://biology-forums.com/gallery/47/medium_262797_12_08_15_1_37_17_22183554.png)