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.
Conclusions Studies from various laboratories have demonstrated the presence of a number of receptor systems on sympathetic nerve terminals innervating the sino-atrial node. A diagramatic representation of all the presynaptic receptor mechanisms discussed in this review is shown in Figure 1.