Intro to the Autonomic Nervous System Flashcards
Parasympathetic nervous system distribution vs sympathetic
Parasympathetic-Limited to head, neck and trunk viscera, never in the body wall or extremities
Sympathetic- distributes to all vascular areas of the body
Glandular secretion controlled by
Parasympathetic nervous system, except sweat glands, the sympathetic nervous system can indirectly decrease non-sweat glandular secretion through vasoconstriction
Vasoconstriction controlled by
Sympathetic nervous system, except coronary artery
Typically parasympathetic stimulation is
Anabolic, normal function and energy conservation
Visceral distribution of Thoracolumbar T1-L2 sympathetic division supply what
Innervation to visceral structures; organs of the trunk Heart, Lungs Liver, Gallbladder GI tract, Spleen Pancreas Kidneys Reproductive organs
Presynaptic fibers of thoracolumbar visceral sympathetic division
They are short
Cell bodies in lateral horn of spinal cord
Always travel in anterior root
Always travel into anterior ramus
Quickly exit anterior ramus and enter paravertebral ganglia
Synaptic options for presynaptic fibers of thoracolumbar visceral sympathetic division
They can enter paravertebral ganglion and synapse on postsynaptic neuron in same spinal level, or ascend or descend to postsynaptic neuron in different level, or exit PV ganglion without synapsing and continue on through an abdominopelvic splanchnic nerve on their way to a postsynaptic neuron in prevertebral ganglion
Postsynaptic fibers
Long
Cell bodies in paravertebral or prevertebral ganglia
Paravertebral ganglia
Linked vertically to form sympathetic trunks on either side of the vertebral column, three ganglia also exist in the cervical, lumbar and pelvic regions
Prevertebral ganglia
Surround the main unpaired branches of abdominal aorta
- Celiac ganglion
- Superior mesenteric ganglion
- Aorticorenal ganglion
- Inferior mesenteric ganglion
Parietal distribution supplies
Sympathetic innervation to smooth muscle of skin and blood vessels, sweat glands
Synaptic options for parietal distribution of presynaptic fibers in trunk vs head/neck/upper extremity
For trunk distribution: PS fibers can enter paravertebral ganglion and synapse at same level
For head, neck and upper extremity, PS fibers enter paravertebral ganglion at their own level then ascend to synapse on a postsynaptic neuron in the cervical sympathetic trunk
Synaptic options for parietal distribution of presynaptic fibers for perineum and lower extremity
PS fibers enter the paravertebral ganglion at their own level and then descend to synapse on a post synaptic neuron in the abdominal and sacral sympathetic trunk
Post synaptic fibers of parietal distribution- cell bodies exist where and exit that space through what
Paravertebral ganglia, exit via gray rami communicantes back into the somatic nerve
Path/trunk distribution of post synaptic fibers in back/posterior
Follow posterior rami of spinal nerves to innervate smooth muscle/sweat glands of back
Path/distribution of post synaptic fibers in anterior/lateral trunk
Follow anterior rami of spinal nerves, which for the trunk are the intercostal, thoracoabdominal and subcostal nerves
Post synaptic parietal fibers distribution in head and face
Fibers follow carotid nerves and enter carotid periarterial plexus
Post synaptic parietal fiber distribution in posterior neck
Follow posterior rami such as suboccipital, greater and least occipital
Post synaptic parietal fiber distribution in anterior neck/upper extremity
Follow anterior rami of spinal nerves which for neck make up the cervical plexus and for upper extremity make up brachial plexus
Post synaptic parietal fiber distribution in buttocks
Fibers follow posterior rami of spinal nerves called cluneal nerves
Post synaptic parietal fiber distribution in perineum and lower extremity
Follow anterior rami of spinal nerves which make up lumbar and sacral plexuses
Parasympathetic nervous system consists of which nerves
Craniosacral CN III (oculomotor), VII (facial), IX (glossopharyngeal) and X (vagus), S2-4
Presynaptic fibers of PNS
Long
Nuclei in brain stem and sacral spinal levels
Cranial component exits as cranial nerves
Sacral components exit spinal levels as pelvic splanchnic nerves
Post synaptic fibers of PNS
Usually short, with ganglia/postsynaptic neurons near or in the target organ
Ciliary ganglion receives fibers from
Oculomotor nerve CN III
Pterygopalatine ganglion receives fibers from
Facial nerve CN VII
Submandibular ganglion receives fibers from
Facial nerve CN VII
Otic ganglion receives fibers from
Glossopharyngeal nerve CN IX
Intrinsic parasympathetic ganglia
These are postsynaptic parasympathetic cell bodies located in the walls of target organs
Autonomic plexuses
Typically mixed sympathetic/parasympathetic plexuses that travel on the vasculature to carry the postsynaptic (for sympathetic division) and presynaptic (for parasympathetic division) to the target organ
Plexuses located in the thorax
Pulmonary
Cardiac
Aortic
Esophageal
Plexuses located in the abdomen
Celiac Hepatic Superior mesenteric Renal Intermesenteric Inferior mesenteric Superior hypogastric
Plexuses located in the pelvis
Inferior hypogastric (pelvic) plexus
Vesical plexus
Uterovaginal plexus
Prostatic plexus
