Sympathetic chains agi Sympathetic S-A nexes node ympailet nerves A-V no FIGURE9-11 Cardiac nerves. (The vagus nerves to the heart are parasympathetic nerves
Cardiac innervation ( contin At rest moderate amount of tonic discharge in the cardiac sympathetic nerves a good deal of tonic vagal discharge (vagal tone) When the vagi are cut in experiment animals. the heart rate rises
Cardiac innervation (contin.) ➢ At rest ➢ moderate amount of tonic discharge in the cardiac sympathetic nerves ➢ a good deal of tonic vagal discharge (vagal tone) ➢ When the vagi are cut in experiment animals, the heart rate rises
Innervation of blood vess Vasomotor center Sympathetic Blood vasoconstrictor fiber Distribution Almost all segments of the circulation The innervation is powerful in the kidneys essel gut, spleen and skin, is less potent in both skeletal and cardiac muscle and in the brain
Innervation of blood vessels ➢ Sympathetic vasoconstrictor fiber ➢ Distribution: Almost all segments of the circulation. ➢ The innervation is powerful in the kidneys, gut, spleen and skin, ➢ is less potent in both skeletal and cardiac muscle and in the brain
Innervation of blood vesse Sympathetic vasoconstrictor fiber (contin.) >Almost all vessels. such as arteries arterioles venules and veins are innervated >except the capillaries, precapillary sphincters and most of the metarterioles >Tone: Usually the sympathetic vasoconstrictor fibers keep tonic
Innervation of blood vessels ➢Sympathetic vasoconstrictor fiber (contin.) ➢Almost all vessels, such as arteries, arterioles, venules and veins are innervated, ➢except the capillaries, precapillary sphincters and most of the metarterioles. ➢Tone: Usually the sympathetic vasoconstrictor fibers keep tonic
150 125 Total spinal anesthesia EE900 100 WAMMAAAMMA 75 50 MA WWWA 25 Injection of norepinephrine 20 Minutes