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.
These and other body actions are controlled by the autonomic nervous system. The autonomic nervous system also has two divisions: the sympathetic division and the parasympathetic division. These two divisions have antagonistic (opposing) effects on the internal organs they innervate (send nerves to = act on). The sympathetic division, shown at the left, is the emergency system.