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Author Question: After leaving the area of the AV node, impulses go through the ________ to reach the right and left ... (Read 1871 times) |
In the United States, an estimated 50 million unnecessary antibiotics are prescribed for viral respiratory infections.
It is believed that the Incas used anesthesia. Evidence supports the theory that shamans chewed cocoa leaves and drilled holes into the heads of patients (letting evil spirits escape), spitting into the wounds they made. The mixture of cocaine, saliva, and resin numbed the site enough to allow hours of drilling.
Throughout history, plants containing cardiac steroids have been used as heart drugs and as poisons (e.g., in arrows used in combat), emetics, and diuretics.
Ether was used widely for surgeries but became less popular because of its flammability and its tendency to cause vomiting. In England, it was quickly replaced by chloroform, but this agent caused many deaths and lost popularity.
The immune system needs 9.5 hours of sleep in total darkness to recharge completely.