|
|
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.
Though Candida and Aspergillus species are the most common fungal pathogens causing invasive fungal disease in the immunocompromised, infections due to previously uncommon hyaline and dematiaceous filamentous fungi are occurring more often today. Rare fungal infections, once accurately diagnosed, may require surgical debridement, immunotherapy, and newer antifungals used singly or in combination with older antifungals, on a case-by-case basis.
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.
Pubic lice (crabs) are usually spread through sexual contact. You cannot catch them by using a public toilet.
Not getting enough sleep can greatly weaken the immune system. Lack of sleep makes you more likely to catch a cold, or more difficult to fight off an infection.