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.
Autonomic nervous system - Structure. 1  The autonomic nervous system is divided into the sympathetic nervous system and parasympathetic nervous system. The sympathetic division emerges from the spinal cord in the thoracic and lumbar areas, terminating around L2-3.