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.
Moon Phase Explanation. New Moon-The Moon's unilluminated side is facing the Earth. Waxing Crescent-The Moon appears to be partly but less than one-half illuminated by direct sunlight. First Quarter-One-half of the Moon appears to be illuminated by direct sunlight.Waxing Gibbous-The Moon appears to be more than one-half but not fully illuminated by direct sunlight. Full Moon-The Moon's illuminated side is facing the Earth.Waning Gibbous-The Moon appears to be more than one-half but not fully illuminated by direct sunlight. Last Quarter-One-half of the Moon appears to be illuminated by direct sunlight.irst Quarter-One-half of the Moon appears to be illuminated by direct sunlight. Waxing Gibbous-The Moon appears to be more than one-half but not fully illuminated by direct sunlight. Full Moon-The Moon's illuminated side is facing the Earth.