Lecture 20: Visceral Nervous System Flashcards
what does the ANS innervate (3)
-smooth muscle
-cardiac muscle
-glands
2 branches of visceral nervous system
motor=autonomics
-sensory
how many cell bodies are found in somatic NS
1
how many cell bodies are found in ANS
2 (preganglionic and postganglionic)
where are preganglionic ANS cell bodies found (what system)
CNS
where are postganglionic ANS cell bodies found (what division)
PNS
2 divisions of sensory system of visceral NS
pain
nonpain
which system is the diaphragm apart of and why
somatic NS
can choose to breathe (voluntary control)
3 visceral structures present in body wall
-sweat and sebaceous glands
-arrector pili muscles
-vasculature
body wall includes what
limbs (forepaws, hindpaws) and parts of head and neck
3 distinct pathways of sympathetic NS
-to body wall
-to body cavity cranial to abdominal diaphragm
-to body cavity caudal to abdominal diaphragm
lateral horn contains what kind of cell bodies and at what level
preganglionic sympathetic cell bodies from T1-L4 spinal cord levels
preganglionic sympathetic pathway
lateral horn –> ventral horn –> ventral root –> mixed spinal nerve –> ventral ramus –> white ramus communicans –> paravertebral ganglion –> synapse
what is contained within the paravertebral ganglion
postganglionic sympathetic cell bodies
preganglionic and postganglionic sympathetic pathway: epaxial musculature of body wall
lateral horn –> ventral horn –> ventral rooot –> mixed nerve –> ventral ramus –> white ramus –> paravertebral ganglion (synapse) –> out gray ramus communicans –> dorsal ramus
preganglionic and postganglionic sympathetic pathway: hypaxial musculature of body wall
lateral horn –> ventral horn –> ventral root –> mixed nerve –> ventral ramus –> white ramus –> paravertebral ganglion (synapse) –> out gray ramus communicans –> ventral ramus
preganglionic and postganglionic sympathetic pathway: body cavity cranial to diaphragm
lateral horn –> ventral horn –> ventral root –> mixed nerve –> ventral ramus –> white ramus communicans –> paravertebral ganglion –> synapse –> exit via cadiopulmonary splanchnic nerve
preganglionic and postganglionic sympathetic pathway: body cavity caudal to diaphragm
ateral horn –> ventral horn –> ventral root –> mixed nerve –> ventral ramus –> white ramus communicans –> paravertebral ganglion –> NO synapse –> exit via abdominopelvic splanchnic nerve
preganglionic vs postganglionic cell bodies: locations found
-preganglionic T1-L4
postganglionic at every vertebral level (cauda equina)
sympathetic chain/trunk
line up of all the paravertebral ganglia
what levels are white ramus communicans only found and why
T1-L4
preganglionic sympathetic axons only enter sympathetic chain from T1-L4
places where preganglionic axons (only at T1-L4) can synapse once entering sympathetic chain (4)
-paravertebral ganglion at that level
-move cranially in chain
-move caudally in chain
-exit chain without synapse –> synapse in a paravertebral ganglion on aorta
are there gray ramus communicans at every level
yes
why are there gray ramus communicans at every level
because postganglionic axons exit the chain at every level
cauda equina contains what kind of roots
dorsal and ventral
structures attached to every paravertebral ganglion at every level (5)
-somatic motor cell bodies in ventral horn
-visceral and somatic sensory cell bodies in dorsal root ganglion
-postganglionic sympathetic cell bodies in paravertebral ganglion
-gray ramus communicans
-connection to paravertebral ganglion above and below
2 specialized structures attached to every paravertebral ganglion from T1-L4 spinal cord levels
-preganglionic sympathetic cell bodies in lateral horn
-white ramus communicans
all paravertebral ganglia from T5-T6 are attached to what nerves
abdominopelvic splanchnic
2 structures missing caudal to L4
-no lateral horn (no preganglionic sympathetic cell bodies)
-no white ramus communicans
is there any parasympathetic to the body wall
no
3 parasympathetic pathways
-head and neck
-body caudal to neck including only the thorax, foregut and midgut
-body caudal to neck including only hindgut and pelvic viscera
where is preganglionic parasympathetic cell body found
brain
how does preganglionic parasympathetic axon travel to body
vagus nerve
where do vagus nerve and sympathetic chain separate
-cervical ganglion (C5-C6 paravertebral ganglion)
where do preganglionic parasympathetic axons synapse
on postganglionic cell bodies in ganglia within wall of organ to be innervated
where are postganglionic parasympathetic axons contained
within organ
visceral pain definition
damage of visceral structure
what pathway does visceral pain follow
sympathetic pathway from structure to spinal nerve –> dorsal root ganglion
number of cell bodies in sympathetic visceral pain pathway (and where it’s found)
1 in dorsal root ganglion
nonpain definition/examples
sensations like fullness, bloating and cramping
can be pleasant or unpleasant
does not damage structure
which pathway does nonpain follow
parasympathetic to the brain
referred pain is found in what division of PNS
visceral sensory
referred pain definition
pain signals get mixed up because organs in body cavity are associated with same spinal cord levels that body wall structures are associated with
heart attack: referred pain
-pain in left arm due to similar spinal cord levels
-heart pain: Sensory/afferent cell body –> paravertebral ganglion, no synapse–> white ramus communicans–> ventral ramus –> mixed nerve –> dorsal root ganglion –> dorsal horn –> synapse
-arm pain sensation: mixed communication of visceral pain and somatic pain system
