|
|
For about 100 years, scientists thought that peptic ulcers were caused by stress, spicy food, and alcohol. Later, researchers added stomach acid to the list of causes and began treating ulcers with antacids. Now it is known that peptic ulcers are predominantly caused by Helicobacter pylori, a spiral-shaped bacterium that normally exist in the stomach.
During pregnancy, a woman is more likely to experience bleeding gums and nosebleeds caused by hormonal changes that increase blood flow to the mouth and nose.
The U.S. Preventive Services Task Force recommends that all women age 65 years of age or older should be screened with bone densitometry.
Drug abusers experience the following scenario: The pleasure given by their drug (or drugs) of choice is so strong that it is difficult to eradicate even after years of staying away from the substances involved. Certain triggers may cause a drug abuser to relapse. Research shows that long-term drug abuse results in significant changes in brain function that persist long after an individual stops using drugs. It is most important to realize that the same is true of not just illegal substances but alcohol and tobacco as well.
Cancer has been around as long as humankind, but only in the second half of the twentieth century did the number of cancer cases explode.
![The ovaries. In addition to producing ova, the ovaries secrete the female sex hormones, estrogen and](https://biology-forums.com/gallery/47/medium_14755_28_08_12_1_42_24_8232364.jpeg)
![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)
![A strike by 800 women shoemakers in Lynn, Massachusetts, in 1860. In 1851 a Lynn shoemaker had adapt](https://biology-forums.com/gallery/47/medium_375552_19_08_15_9_09_53_223271453.jpeg)