SYMPATHETIC NERVOUS SYSTEM

The peripheral nervous system is divided into the sensory somatic nervous system and the autonomic nervous system. The sensory nervous system controls the voluntary actions of our skeletal muscles, while the autonomic nervous system controls the involuntary actions of our cardiac muscles, smooth muscles, and glands.

Prepares the body for emergency or to react to a stressful situation.

"fight or flight" situation

In the sympathetic nervous system, the ganglia are grouped in a long chain just outside the spinal cord. When the ganglia receive the right "emergency" impulse from the spinal cord, the entire body reacts. All organs are on alert and ready at the same time



PARASYMPATHETIC NERVOUS SYSTEM

PARASYMPATHETIC NERVOUS SYSTEM

 

• Is the aftermath of the fight or flight response.
• Calms the body down in order to gain homeostasis
• It can constrict your lungs to slow your breathing, reduce your heartbeat, or stimulate digestion

In the parasympathetic nervous system, the ganglia are located in groups along certain cranial nerves.



GLOSSARY

sensory neuron~are nerve cells that transmit sensory information (sight, sound, feeling, etc.). They are activated by sensory input, and send projections to other elements of the nervous system, ultimately conveying sensory information to the brain or spinal cord.


interneuron~a neuron that transmits impulses between other neurons, especially as part of a reflex arc.

preganglionic motor neuron~A motor neuron having a cell body located in the brain or spinal cord and a myelinated axon that travels out of the central nervous system as part of a cranial or spinal nerve before separating and extending into the autonomic ganglion.


chain ganglia~The bilaterally symmetric sympathetic chain ganglia, also called the paravertebral ganglia, are located just ventral and lateral to the spinal cord. The chain extends from the upper neck down to the coccyx, forming the unpaired coccygeal ganglion.

postganglionic motor neuron~A motor neuron that forms a synapse with one or more preganglionic motor neurons, is located outside the central nervous system and has its unmyelinated axon ending in smooth muscle, cardiac muscle, or a gland.

Effector organ~cause something to happen. They produce an effect after the nerve has been stimulated, such as a muscle contracting or a gland secreting a substance.

Reason~a reaction to something