查看Ch14 The Autonomic Nervous System的源代码

=== 副交感神经元参与许多简单的不自主反射 ===
<b style=color:#0ae>Parasympathetic neurons participate in many simple involuntary reflexes</b>

As opposed to neurons in the sympathetic division, neurons in the parasympathetic division function only in a discrete, organ-specific, and reflexive manner. Together with specific visceral afferents and a small number of interneurons, parasympathetic neurons mediate simple reflexes involving target organs. For example, the output of the baroreceptor reflex (see pp. 537–539) is mediated by preganglionic parasympathetic neurons in the dorsal motor nucleus of the vagus. Other examples include urination in response to bladder distention (see pp. 736–737); salivation in response to the sight or smell of food (see p. 895); vagovagal reflexes (see p. 857) in the GI tract, such as contraction of the colon in response to food in the stomach; and bronchoconstriction in response to activation of receptors in the lungs (see pp. 717– 718). The pupillary light reflex is an example of an involuntary parasympathetic reflex that can be tested at the bedside (see p. 362).

与交感神经部的神经元相反，副交感神经部的神经元仅以离散的、器官特异性和反射性的方式发挥作用。副交感神经元与特定的内脏传入神经和少量中间神经元一起介导涉及靶器官的简单反射。例如，压力感受器反射的输出（见第 537-539 页）是由迷走神经背侧运动核中的节前副交感神经元介导的。其他例子包括对膀胱膨胀的反应排尿（见第 736-737 页）；对食物的视觉或气味产生流涎（见第 895 页）；胃肠道中的阴道反射（见第 857 页），例如结肠对胃中食物的反应收缩和响应肺部受体激活的支气管收缩（见第 717-718 页）。瞳孔对光反射是可以在床边测试的非自主副交感神经反射的一个例子（见第 362 页）。

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