Fox squirrel (Sciurus niger): The fox squirrel is the largest tree squirrel in Illinois, weighing one and three-quarters to two pounds with a length of 19 Â½ to 22 inches. The fur is a mix of rusty-yellow with black with an overall reddish cast. The fur on the ears, belly, and edge of the tail is lighter.
Audiologists are able to measure the speed and intensity of these pulses to determine if there is hearing loss or a lesion that is upsetting the flow of the sound information through the brainstem. This measurement is called a brainstem auditory evoked response (BAER).
The brainstem is the part of the brain where the body's vital functions are controlled - the breathing, the heart, the brain itself; it is the computer room of the body. If that bit of the brain is dead, then the person is essentially dead. You can still have reflex actions, so you may twitch after death. To certify that someone is dead, you listen to the heart for one minute and feel for a pulse for one minute.