The Parasympathetic and Sympathetic Divisions Flashcards
Stimulation and inhibition by both the sympathetic and parasympathetic divisions that counterbalance each other to keep body systems running smoothly.
Dual Innervation
Parasympathetic Division: Origin
Craniosacral part: Brain Stem Nuclei of Cranial Nerves III, VII, IX, and X. Spinal Cord Segments S2-S4
Sympathetic Division: Origin
Thoracolumbar part: lateral horns of gray matter of spinal cord segments T1-L2.
Parasympathetic Division: Location of Ganglia
Ganglia are within the visceral organ or close to the organ served.
Sympathetic Division: Location of Ganglia
Ganglia are within a few centimeters of CNS: alongside vertebral column or anterior to vertebral column.
Parasympathetic Division: Relative Lengths of Fibers.
Long preganglionic; short postganglionic.
Sympathetic Division: Relative Lengths of Fibers.
Short preganglionic; long postganglionic.
Parasympathetic Division: Functional Role
Maintenance functions; conserves and stores energy; “rest and digest”
Sympathetic Division: Functional Role
Prepares body for activity; “fight or flight”
Parasympathetic Division: Neurotransmitters
All preganglionic and postganglionic fibers release Ach
Sympathetic Division: Neurotransmitters
All preganglionic fibers release Ach. Most postganglionic fibers release norepinephrine. Postganglionic fibers serving sweat glands release Ach. Neurotransmitter activity is augmented by release of adrenal medullary hormones.
Division where the preganglionic fibers spring from the brain stem and sacral region of the spinal cord. AKA the parasympathetic division.
Craniosacral Division
Location of synapse between preganglionic and postganglionic neurons in the parasympathetic division. Located close to target organs.
Terminal Ganglia
Innervate smooth muscles in the eyes that cause the pupils to constrict and the lenses to bulge.
Oculomotor Nerves
Stimulates many glands in the head: nasal glands, lacrimal glands, submandibular and sublingual salivary glands.
Facial Nerves
Stimulates the parotid salivary glands.
Glossopharyngeal Nerves
Provide fibers to the neck and to nerve plexuses that serve virtually every organ in the thoracic and abdominal cavities. Contains the cardiac plexus, the pulmonary plexus, and esophageal plexus.
Vagus Nerves
Contains parasympathetic nerve fibers that innervate the distal half of the large intestine, urinary bladder, ureters, and reproductive organs.
Spinal Nerves S2-S4
Division where preganglionic fibers arise from spinal cord segments T1-L2. AKA the sympathetic division.
Thoracolumbar Division
Formed by the cell bodies of preganglionic sympathetic neurons.
Lateral Horns
Send information about chemical changes, stretch, temperature, and irritation of the viscera.
Visceral Sensory Neurons
Similar to somatic reflex arcs, but contain two consecutive neurons in the motor component.
Visceral Reflex Arcs
Pain stimuli arising from the viscera, but perceived as somatic in origin. Due to visceral pain sensory fibers converge on the same second-order sensory neurons that receive information from somatic sensory neurons.
Referred Pain
