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.
The S-A node is innervated by vagal (parasympathetic) and sympathetic fibers. Sympathetic efferent nerves are present throughout the atria (especially in the S-A node) and ventricles, and in the conduction system of the heart.