Crystal Chiropractic
Dr. Crystal A. Galvan, D.C.
3022 State Street Ste B
Santa Barbara, Ca 93105
Phone: (805) 687-8900
The Nervous System
The nervous system coordinates the activity of the muscles, monitors the organs, constructs and also stops input from the senses, and starts actions. Prominent participants in a nervous system include neurons and nerves, which play roles in such coordination.
THE PNS
The somatic nervous system is that part of the peripheral nervous system (PNS),
associated with the voluntary control of body movements through the action of skeletal
muscles, and also reception of external stimuli. The somatic nervous system consists of
afferent fibers that receive information from external sources, and efferent fibers that are
responsible for muscle contraction.
The somatic system includes all the neurons connected with the muscles, sense organs
and skin. It deals with sensory information and controls the movement of the body.
THE CNS
The central nervous system (CNS) makes up the largest part of the nervous system,
including the brain and the spinal cord. Together with the peripheral nervous system, it has
a fundamental role in the control of behaviors.
The CNS is as a system devoted to information processing, where an appropriate motor
output is computed as a response to a sensory information. Research suggest that motor
activity exists well before the maturation of the sensory systems so, that the senses only
influence behavior without dictating it. This has brought the conception of the CNS as an
autonomous system.
The sympathetic nervous system activates the fight or flight response. This response that
acts primarily on the cardiovascular system is mediated directly via impulses transmitted by
the sympathetic nervous system.
Science typically looks at the CNS as an automatic regulation system. A system that
operates without the intervention of conscious thought. One example of this is in the
moments before waking, in which sympathetic outflow spontaneously increases in
preparation for action
The parasympathetic nervous system is part of the autonomic nervous system. Sometimes
called the rest and digest system, the parasympathetic system conserves energy as it
slows the heart rate, increases intestinal and gland activity, and relaxes muscles in the GI
tract. The regions of the body associated with this division are the cranial and sacral
regions of the spinal cord.
Sympathetic and parasympathetic divisions typically function in opposition to each other.
But this opposition is better termed complementary in nature. Think of the sympathetic
division as the accelerator and the parasympathetic division as the brake. The sympathetic
division typically functions in actions requiring quick responses. The parasympathetic
division functions with actions that do not require immediate reaction. Consider
sympathetic as "fight or flight" and parasympathetic as "rest and digest".
THE BRAIN
The brain, is the control center of the central nervous system. The brain is located in the head, protected by the skull and close to the primary sensory organs of vision, hearing, taste and smell. In humans, it is an organ of thought. Brains can be extremely complex. The human brain contains more than 100 billion neurons.
THE SPINAL CORD
The spinal cord is an extension of the central nervous system from the brain and is enclosed in and protected by the bony vertebral column. The main function of the spinal cord is transmission of neural inputs from the body to the brain and vice versa and is a vital structure in our survival and functional capacity.
