|
|
The familiar sounds of your heart are made by the heart's valves as they open and close.
Hypertension is a silent killer because it is deadly and has no significant early symptoms. The danger from hypertension is the extra load on the heart, which can lead to hypertensive heart disease and kidney damage. This occurs without any major symptoms until the high blood pressure becomes extreme. Regular blood pressure checks are an important method of catching hypertension before it can kill you.
There are more nerve cells in one human brain than there are stars in the Milky Way.
In 1835 it was discovered that a disease of silkworms known as muscardine could be transferred from one silkworm to another, and was caused by a fungus.
According to the American College of Allergy, Asthma & Immunology, more than 50 million Americans have some kind of food allergy. Food allergies affect between 4 and 6% of children, and 4% of adults, according to the CDC. The most common food allergies include shellfish, peanuts, walnuts, fish, eggs, milk, and soy.
![The functional structure of the peripheral nervous system. (A) Afferent or sensory neurons carry sen](https://biology-forums.com/gallery/47/medium_14755_27_08_12_4_56_12_8219264.jpeg)
![(A) Each bronchiole terminates in an alveolar sac, a group of alveoli; (B) alveoli encased by networ](https://biology-forums.com/gallery/47/medium_14755_10_09_12_7_13_31_84891921.jpeg)