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.
The Phases of the Moon. Half of the Moonâs surface is always illuminated by sunlight. However, just how much of that light we can see from our point of view on Earth varies every day and this is what we refer to as a Moon phase. The 7 visible Moon phases. The 7 visible Moon phases are pictured here. The New Moon cannot be seen from Earth. Â©bigstockphoto.com/Kagenmi. Sun Lights Up the Moon. The Moon does not radiate its own light, but the Moon's surface reflects the Sunâs rays. Primary and Intermediate Phases. In Western Culture, we divide the lunar month into 4 primary and 4 intermediate Moon phases. Technically, the primary Moon phases occur at a specific moment in time, and the intermediate Moon phases take up the time in between. Opposite phases on the far side of the Moon. New Moon