autonomic nervous system Flashcards
3 divisions of ANS
- sympathic
- parasympathic
- enteric
2 pathways along which output from the CNS travels
- somatic motor neurons (innervate striated skeletel muscle)
- autonomic motor neurons (innervate smooth muscle, cardiac muscle, secretory
epithelia and glands)
which division of the ANS will have an increased output when dealing with stress, anxiety, physical activity, fear of excitement
the sympathetic division
wich division of the ANS will have an increased output when doing a sendentary activity, eating of with other ‘vegetative’ behaviour
the parasympathetic division
where do the preganglionic neurons lay
in columns of cells in the brainstem and the spinal cord
what do the preganglionic neurons make synapses with
postganglionic neurons in peripheral ganglia
the enteric division of the ANS is a collection of what
afferent neurons, interneurons and motor neurons
what do the collection of neurons from the enteric division form
networks of neurons called plexuses
what do plexuses surround
the gastrointestinal (GI) tract
what is the enteric division normally controlled by
the CNS through sympathetic and parasympathetic fibers
what spinal segments do sympathetic preganglionic neurons originate from
T1 to L3
where do the autonomic neurons between levels T1 and L3 lie
in the intermediolateral cell column
3 groups of nuclei from which preganglionic parasympathetic neurons that are distributed with CN III, CN VII, and CN IX originate
- Edinger-Wetsphal nucleus
- superior salivatory nucleus
- inferior salivatory nucleus
parasympathetic neurons in the Edinger-Westphal nucleus travel in the ….. nerve (CN …) and synapse onto postganglionic neurons in the ….. ganglion
oculomotor nerve (CN III), ciliary ganglion
what is the Edinger-Westphal nucleus a subnucleus of
the oculomotor complex in the midbrain
to which two smooth muscles of the ete do the postganglionic fibers of the Edinger-Westphal nucleus project to
- the constrictor muscle of the pupil
- the ciliary muscle (which controls shape of the lens)
which two ganglia are at the end of branches of the facial nerve that are targets for the superior salivatory nucleus
- pterygopalatine ganglion
- submandibular ganglion
which two salivary glands do the postganglionic fibers of the submandibular ganglion supply
- submandibular
- sublingual
what do the postganglionic fibers of the pterygopalatine ganglion supply
lacrimal glands
where is the superior salivatory nucleus situated
in the rostral medulla
what nerve is related to the superior salivatory nucleus
the facial nerve (CN VII)
which third salivary gland do the postganglionic fibers of the otic ganglion supply
the parotid gland
which nerve is associated with the inferior salivatory nucleus
glossopharyngeal nerve (CN IX)
what does the inferior salivatory nucleus work together with
the rostral part of the nucleus ambiguus
through which nerve does moest parasympathetic output occur
the vagus nerve (CN X)
where are cell bodies of vagal preganglionic parasympathetic neurons found
in the medulla within the nucleus ambiguus and the dorsal motor nucleus of the vagus
the vagus nerve supplies parasympathetic innervation to all viscera of which two regions
thorax and abdomen
what does electrical stimulation of the nucleus ambiguus result in
- contraction of striated muscle in the pharynx, larynx and upper esophagus due to
activation of somatic motor neurons - slowing of the heart due to activation of vagal preganglionic parasympathetic neurons
what’s an effect of stimulation of the sorsal motor nucleus of the vagus nerve
initiation of secretion of gastric acis, insulin and glucagon
which plexuses do preganglionic parasympathetic fibers of the vagus nerve join
- esophageal
- pulmonary
- cardiac
do the axons of sacral nerves leave through ventral roots or dorsal roots
ventral roots
with which nerves do the axons of sacral nerves travel
pelvic splanchnic nerves
where are the terminal ganglia of the sacral nerves situated
- in the descending colon and rectum
- the bladder
- reproductive organs
many visceral nociceptive fibers travel in the sympathetic/ parasympathetic nerves
most axons from physiological receptors travel with sympathetic/ parasympathetic fibers
where are the cell bodies of visceral afferent fibers located
within the dorsal root ganglia or cranial nerve ganglia
where can the largest concentration of visceral afferent axons be found
in the vagus nerve
in which ganglion are cell bodies of the vagal afferents located
in the nodose ganglion
what do the vagal afferents carry information about
the distention of hollow organs, blood gasses and body chemistry
where do vagal affernts carry information to
the medulla
what’s the consequence of the fact that viscerotopic mapping is present in the brainstem but not at the level of the cerebral cortex
there is ‘referred’ pain
what’s ENS the abbreviation for
enteric nervous system
the ENS is a collection of …….. that surround the … tract, including the ….. and ….. system
nerve plexuses, GI, pancreas, biliary
where does the myenteric or Auerbach’s plexus lie
between the outer longitudinal and the inner circular layers of smooth muscle
where does the submucosal or Meissner’s plexus lie
between the inner circular and most internal layer of smooth muscle
synonym for the most internal layer of smooth muscle
muscularis mucosae
what is the myenteric plexus involved in in the intestinal wall
control of motility
hat is the submucosal plexus involved in in the intestinal wall
control of ion and fluid transport
from what nerve do both myenteric and submucosal plexuses receive preganglionic parasympathetic innervation from
vagus nerve (or sacral nerve sin the case of the distal portion of colon and rection)
