More early signs of pregnancy include an aching head, a result of changes in hormones. Just in case you are indeed pregnant, take pg-safe acetaminophen instead of ibuprofen to deal with the pain.
Organs Without Dual Innervation. Although most organs are innervated by both sympathetic and parasympathetic nerves, some-including the adrenal medulla, arrector pili muscles, sweat glands, and most blood vessels-receive only sympathetic innervation.
This system is further divided into two branches: the sympathetic system and the parasympathetic system. 1  The sympathetic division of the autonomic nervous system regulates the flight-or-fight responses. This division also performs such tasks as relaxing the bladder, speeding up heart rate and dilating eye pupils.