The term autonomic nervous system (ANS) refers to collections of motor neurons (ganglia) situated in the head, neck, thorax, abdomen, and pelvis, and to the axonal connections of these neurons (Figure 1).rain and spinal cord pathways regulating autonomic outflow. Preganglionic neurons for parasympathetic and sympathetic autonomic outflow are located in the brainstem and in thoracic, upper lumbar and sacral regions of the spinal cord (Figure 1). Several different brain centres control these preganglionic neurons.
A: Moon phases are caused by the motions of the Earth and moon as they relate to the sun. Phases occur as the Earth-facing side of the moon changes over the course of 29.5 days when the moon revolves around the planet. When the angle of sunlight reflecting off the moon changes, humans observe different lighting levels from the moon.
Determining Moon Phases in the Northern Hemisphere. 1  1. Recognize that the moon waxes and wanes from right to left. 2  2. Remember D, O, C. Since the moon always follows the same illumination pattern, you can use the shape of the letters D, O, and C to determine if the moon is waxing or waning. 3  3. Learn when the moon rises and sets.