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.
Sympathetic Pathways. Neurons of the sympathetic division of the autonomic nervous system are aggregated into two main collections of ganglia: the paravertebral ganglia, which form the sympathetic chain each side of the vertebral column, and the prevertebral ganglia lying around the origins of the coeliac and mesenteric arteries ( Figure 1).