The PNS is made of ___ and ____ nerves, but we are focusing on the former for now.
spinal and cranial
The Spinal cord (____) is organized into ___ levels, with a pair of spinal nerves (_____) emerging from each level. There are _ cervical spinal cord levels and _ sets of C spinal nerves;
There are __ thoracic levels&nerve pairs
There are __ lumbar spinal cord levels and nerve pairs
There are ___ sacral levels and nerve pairs
There are ___ coccygeal levels and nerve pairs.
The spinal cord is _____ than the vetebral column
The adult vertebral column consists of 33 vertebrae arranged in ____ regions. Say region name and number:
5 sacral (fused)
4 coccygeal (fused).
What is the Arrow pointing to and what is it's significance ?
the spinal nerves exit through here
A good rule of thumb for naming spinal nerves is that C1-C7 are named for the vetebra ____ to their exit while C8 is between __ and ___ then below C8 all are named for the vertebra _____ to their exit.
- c7 and T1
In the adult, the spinal cord narrows to form the tapered area called the ____ ____ , which ends at ___ vetebral level. Because of this discrepancy in length between spinal cord and vertebral column, the more caudal nerves are _____ and more _____, forming the ______ ____.
- conus medullaris
- cauda equina
The Cauda Equina is housed in a widened area of the ______ ____ called the ____ _____. This area is filled with ___ and is the site where a _____ ____ would occur to get a CSF sample or drugs would be administered because no nerve damge would take place. (like stabbing spaghet with a fork aka hard to do)
- subarachnoid space
- (lumbar cistern)
- Lumbar puncture
Since the SC is shorter than the vetebral column, is must be stabilized. Extensions of the ___ ____ do this transversly and longitudinally. The _____ ____ will anchor the SC with the VC transversely. The _____ _____ is a pia extension that goes from the _____ ___ to the _______ to anchor is longitudinally.
Spinal nerves DO NOT go ____ to ____
DO NOT go directly to organs
Somatic fibers are going to the ____ ____ or ___.
If it is somatic sensory fiber then it is brining info from the?
If it is somatic motor fiber then it is brining info from a?
body wall or the limbs
then it is bringing info from the skin (pain temp, touch
a skeletal muscle.
Viscera should remind you of what 3 things?
Visceral NS supply things like?
cardiac muscle, smooth muscle, and glands
You have the same number of spinal cord nerves pairs and?
spinal cord levels
The _____ ____ is the part of the vertebrae that is antertior and is used for support
_____ _____ are found between the vertebrae to act as a _____
Because the spinal cord is shorter than the vertebral column, it must be _____, to do this, extensions of ____ ____ are used.
________ _______ anchor the spinal chord transversely with vertebral column; they get their name because they look like ____.
The _____ _____ is a pia extention that goes from ______ _____ to the ____ so it can attach; this anchors the spinal cord longitudinally.
How is the cauda equina stabilized?
The nerve roots from the CE are exiting the vetrebal column and since each nerve is going through the interveterbral foramen, they use this as stability
The filum terminale must pierce the ____ ____ ( the dura mater that continues around the conus medularis) to reach the coccxy
Spinal nerves that are going out to are arms, legs, and trunk are _____ which means they have ____ and _____ fibers
The dorsal part of the spinal cord is generally more _____ while the ventral part is more _____. So the sensory info is going to come in via the ____ side while motor info is going to leave via the ____- side
- intervetebral foramen
- dorsal root
- dorsal root ganglion
- dorsal ramus
- true spinal nerve (nerve root)
- ventral ramus
- ventral root
- sympathetic ganglion
- sympathtehtic trunk
- rami communicans
When the dorsal and ventral roots come together, they form the _____ ___ ___- this merges at the ____ _____. However, the TSN is very ____. It will branch into the ___ and ____ ____; both rami are ___.
true spinal nerve
dorsal and ventral rami
Sometimes the ventral ramus gives off sensory branches called ______ branches that go to the ___
The dorsal ramus will supply the ____, the ___ ____, and any _____ in the back. The dorsal rami remain seperate or ____. There is a dorsal rumus for ___ ____ ____, and since they are seperate, it's like stripes on your back.
each spinal nerve
The ventral rami of the _____ nerves remain segmental
Some ventral rami are going to ___ and form a ____. ____ ___ come out of a plexus.
Having a plexus is kinda like having _____ to help if something gets damaged.
What is a dermatome?
Dermatome: a strip of skin supplied by sensory branches of dorsal and ventral rami from one spinal cord level
___dermatome is at the level of the nipple
____ is at the level of the belly button
The limbs also have dermatomes too but they are not as clean due to the way the limbs develop. Fibers from a single spinal cord level in the limbs may be carried by several ____ ____ arising from a_____
several peripheral nerves
For example, C6 fibers may be carried in more than one ____ ____ that are distinct branches from a _____.
What is radiculopathy?
compression or inflammation of the nerve root or true spinal nerve
What is a myotome?
Groups of muscles innervated by a single spinal nerve
Viruses that infect spinal nerves, such as _____ ____ (_____) infections , can reveal their origin by showing up as a painful dermatomic area. In fact, this virus can lay dormant in the ____ ____ ___ and migrate along the ____ ____ to affect only the area of skin served by that nerve.
dorsal root ganglion
What is the motor component of the Visceral nervous sytem called?
This is a motor system which means the signal originates in the ___ __ ____ and moves out to a target.
What are the targets(3)?
What are the 2 divisions of the autonomic NS?
describe each generally:
Parasympathetic- Rest and Digest
Sympathatic- Fight or Flight
Visceral sensory organs are necessary to detect ____ (or other things that are wrong) in internal organs
The cell bodies for motor neurons are housed where?
The ventral horn of the spinal cord (GRAY MATTER)
Sensory is _____ and motor is _____
Somatic sensory (afferent) fibers bring input to ___ from skin or skeletal muscle. The cell bodies are housed in the ___ ____ ___or spinal ganglion. No _____ will occur in the sensory ganglia.
- Skeletal Muscle
- dorsal root ganglia
When a muscle tendon is tapped briskly, the muscle immediately contracts due to a two-neuron reflex arc involving the spinal segment that innervates the muscle. First, a ____ neuron will get the info and synapse with a _____ neuron to perform movement. This allows you check on all nerves involved.
Visceral sensory neurons will detect things like ____ or __ __ in _____ _____, ____ _____, and ______. First, it will get the info and transfer it to the ____. It's cell body is housed in the _____ ___ ____.
dorsal root ganglion
Autonomic ganglion (do/don't) have synapses.
What visceral system does the yellow line represent?
Where is its cell body gonna be located?
What system do the pink and red lines represent?
Name each neuron and tell me where the first both cell bodies are kept.
What is the postgang going to innervate?
The visceral sensory system
the visceral motor system
Red is preganglionic with its cell body in the CNS
the pink is post ganglionic and the cell body is in an autonomic ganglion
glanglion, cardiac or smooth muscle
What are the 3 types of autonomic ganglia?
paravertebral ganglia (the sym. trunk/chain)
intramural ganglia(terminal ganglia)
The paravetebral ganglia or the ___ ___ is for ____ ___ only. Here ______ _____ neurons can synapse on _______. These neurons will innervate the ___ ___, ___, or ____.
postganglionic sympathetic neurons
body wall, limbs, or thorax
The prevetebral ganglia are used for only for the ____ division of the ANS and have neurons that can innervate the ____ and ____ targets.
The visceral parasympathetic neurons will synapse in the ______ _____ (____ ____) that is close to the target organ. These targets are in the ____, _____, or ____. _____ parasympathetic synapses will occur here.
Preganglionic cell bodiesor the sympathetic division of the ANS are localized in the ____ ____ ____ of the spinal cord from segments ___-___ only. It is referred to as being ______ in distribution.
- intermediolateral grey horn (lateral)
So a preganglionic sympathetic cell body is always going to begin in the ____ no matter where it is going, then it will send its axon out through the ___ ___. If it is going to supply the body wall, limbs, or thorax and needs off within the T1-L2 area, the axon will need to travel througha ___ ___ to get into the ______ ____. Next, the neuron will ____ with a _____ _____ neuron. To get back into the spinal nerve, the axon of the post gang. neuron needs to take a ___ ___ as an exit ramp. Now, this nerve can innervate a gland or smooth muscle in the target areas.
IML (intermediolateral gray horn)
white ramus (white ramus communicans)
paravetebral ganglia (sym trunk)
A white ramus is _____ whereas a gray ramus is not.
What rami are only found within the levels of ___-___. gray rami are found at ___ vetebral level of the spinal cord that has a ____ ___.
To get ________ nerves above or below __-__, the neuron would take a white ramus to enter the sympathetic trunk, then it would ascend or descend to the appropriate level before it synapses. The postganglionic neurons takes a gray ramus out into the spinal nerve.
To get a sympathetic nerve to an organ, the preganglionic sympathatic cell body starts in the ___, and the axon travels through the ___ ___ and the ___ ___ ___ then takes a __ ___ to the _____ ____ and synapses with a ____ _____ neuron. To get to an organ, the axon of the postgang. neuron will travel ____ through a ____ ___ ___.
true spinal nerve
sympathetic splanchnich nerve
Splanchnich nerves travel to ____ ___
To get sympathetic nerves to the abdomen and pelvis, the cell body will start in the ___ of the ___ ___ then the axon will exit the ___ ___ through the ___ __ ___ and take a white ramus to enter the ____ ____. HOWEVER! It __ ___ ___ in the sympathatetic trunk , instead, it will take a ____ ___ to exit the trunk and go to synapse in a ____ ____ usually close to the target. After the synapse, the axon leaves the ganglion and travels in an ___ ___
true spinal nerve
DOES NOT SYNAPSE
Cell bodies for the parasympathetic division of the ANS are localized in the nuclei of the ___ ___ and in spinal cord segments ___-___. Because of the cell body placement, the parasym. is referred to as being craniosacral in distribution.
Parasympathetic axons either travel through ____ ___(III, VII, IX, ____ (___)) or
The _____nerve will carry preganglionic parasympathetic axons fibers to its organs of interest where it can synapse in a ___ __. It only supplies the to _____, ______, , and up to the ____ ___ of the_____.
thorax, abdomen, and and up to the middle part of the colon
The S2-4 parasym. preganglionic fibers will travel out through ____ ____ ____ and will be able to synapse in the ____ ___
pelvic splanchnich nerves
____ ____ neurons carry sensory information (distension, pain) from viscera to the CNS and their cell cell bodies are housed in ____ _____ _____. Simulatenously, sensory fibers from areas like the ____ are also coming into the DRG. When something highly stimulating happens, like a heart attack, the cells in the DRG think the pain is also coming from the skin, so you feel pain in the heart and the skin. This is called ____ ____.
spinal/dorsal root ganglion
When visceral afferents are getting info back to the CNS, they travel through the_____ ____, through a _____ ____, through the_____ ____ as an elevator, through a ____ _____, then the____ ____ ____, through the ____where their cell body is housed, and finally synapse in the _____ ___ or a _____.
true spinal nerve