STAT 101 Chapter Notes - Chapter 582: Oncotic Pressure, Venous Blood, Blood Proteins
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1. parasympathetic innervation of the heart is partially controlled by the vagus nerve and is shared by the thoracic ganglia. Autonomic outflow from the medulla is divided principally into sympathetic and parasympathetic (vagal) branches: sympathetic neurons cause pacemaker cells to generate action potentials more frequently, and thus increase heart rate. In contrast, parasympathetic neurons have the opposite effect; they cause a decrease in the frequency of action potentials generated by pacemaker cells, and thus decrease heart rate. The heart simultaneously receives both sympathetic and parasympathetic signals in a push-pull manner. Increases in one are accompanied by decreases in the other: this circulatory system is also responsible for temperature control throughout the body. Blood pressure could be considered the body"s heating and cooling system. p. 586 #1-3: capillary walls are composed of a single layer of endothelial cells, capillaries are the smallest of the body"s blood vessels.