Exam 1 (sc and meninges)
dermatome
Area of skin supplied by a single spinal nerve
Below c7 cervical vertebra spinal nerves exit in what fashion
BELOW respective vertebra
interomediolateral cell column (IML) location
Between anterior and posterior horns
Upper limb plexus of nerves
Brachial plexus (UL)
segmental arteries in spinal cord come from
Branch from Arteries that supply blood to the posterior body walk in different regions
Ventral ramus
Branches to the anterior of the body. Both sensory and motor travel this way.
MEMORIZE BRACHIAL PLEXUS
By Jan 14
Location cervical enlargement
C4-T1
subarachnoid space contains what important fluid
CSF. That supports sc. as well as pushes arachnoid mater against dura.
spinal nerves
Carey sensory and motor fibers. They are mixed nerves
Why does the ventral root not have swelling?
Cell bodies are in ventral horn
Which spinal nerves are shorter
Cervical
What plexuses should we know exist
Cervical brachial lumbar sacral plexuses
Pia mater continues on until
Co1
bulge on posterior of spinal cord
DRG
Specifically what arteries do segmental arteries in the spinal cord branch from?
Deep cervical artery / vertebral artery Posterior intercostal a. Lumbar a. Lateral sacral a.
anterior cutaneous branch
In anterior, goes to skin, sensory only.
Brain stem resides
In cranial cavity
Which spinal nerves have to travel further to get to their intervertebral foramen?
Inferior spinal nerves
The ventral ramus in the anterior trunk name becomes
Intercostal nerve
Know the figure for anterior and posterior radicular arteries blood in
Know the blood out figure
Where does spinal cord end
L1-L2
conus medullaris location
L1-L2
Location lumbar enlargement
L2-S3
Subarachnoid space location
Lies deep to the arachnoid mater
Where do they draw when drawing CSF?
Low to avoid injury. Spinal tap.
Lower limb plexus of nerves
Lumbosacral plexus
Example L5 is far from its intervertebral foramen. When throw out back feel it in lower limbs.
Morphology difference is important to consider clinically
Because at every level the vertebral venous plexuses anastomose with wackier and regional veins what does this allow for?
Provides a conduit for spread of infection and cancer etc
Radish / affecting roots
Radiculopathy
A peripheral nerve may contain fibers associated with more than one spinal cord segment t or f?
T. Ulnar nerve. Contains fibers associated with spinal cord segments c8 and t1
Beginning of sympathetic nervous system
T1-L2
Preganglionic sympathetic neurons are always located at these levels
T1-L2
level of umbilicus
T10
Lowest extent of trunk level
T12/L1
Level of the Areola is what nerve
T4
subdural space
space between dura mater and arachnoid mater. Lies deep to dura. And superficial to arachnoid.
vertebral column
spine
Which vessels are located in the epidural space of the vertebral column?
internal venous plexus
Where do spinal nerves pass through
intervertebral foramen
white matter of spinal cord
This area surrounds the gray matter. It is composed of both myelinated and unmyelinated axons.
When spinal nerves don't merge they cause
True segmentation of spinal cord
Dermatome: Clinical
Used in determining level of spinal injuries Anesthetic injections for surgeries Shingles
Contains somatic motor neurons that innervate skeletal muscles
Ventral horn
Ulnar and sciatic nerve are an example of which rami
Ventral rami, with mixed nerve function
Innervates hypoxia muscles and overlying skin branches out to front to the body. Motor and sensory. Innervates somatic
Ventral ramus
Anterior vertebral artery via
Vertebral artery
intervertebral foramen
What is the name of the opening thru which the spinal nerves pass after branching from the spinal chord?
plexus of nerves
When spinal nerves merge together
Somatic nerve plexus
Where nerves merge and diverge Segmentation exists just more complicated
hemiazygous vein
Which of these blood vessels is located on the left side of the median plane below the heart
the spinal cord is composed of bundles of ascending and descending myelinated fibers called
White matter
filum terminale
fibrous extension of the pia mater that arises from conus medullaris; anchors the spinal cord to the coccyx
avascular meningeal layer
Arachnoid membrane
Anterior vertebral artery how many ?
1
coccygeal # of spinal nerves
1
coccygeal spinal nerves
1 pair (Co1)
Thoracic number of nerves
12
thoracic spinal nerves
12 pairs (T1-T12)
Posterior vertebral artery how many?
2
How can you tell the front and back of the spine?
2 vertebral arteries indicates posterior 1 vertebral arteries indicate anterior
Lumbar # of nerves
5
Sacral # of nerves
5
lumbar spinal nerves
5 pairs (L1-L5)
sacral spinal nerves
5 pairs (S1-S5)
Cervical # of nerves
8
cervical spinal nerves
8 pairs (C1-C8)
Above 7th cervical vertebra spinal nerves exit in what fashion
ABOVE respective vertebra
cauda equina
Dorsal and ventral roots of the inferior spinal cords segmented L2-Co1 that travel inferiorly in the vertebral canal until they can exit out proper vertebral foramen
Part of spinal cord that receives inputs from afferent fibers
Dorsal horn
Innervates epaxial muscles and overlying skin branch leading toward back of body
Dorsal ramus
where the unipolar neuron stretched through to the dorsal horn
Dorsal root
Why do enlargements exist?
Due to increased neuronal density in the areas that supply UL and LL
Dural sleeves
Dura mater extends out along each spinal nerve to the distal end of the ganglion where is becomes continuous with the epineurium
Order of meninges and spaces (superficial to deep)
Epidural space Dura mater Subdural space (doesn't alw exist) Arachnoid mem Subarachnoid space (CSF) Spinal cord
Passes with neuronal fibers of the cauda equina to fuse the vertebral column in the region of the coccyx
Filum terminale
Length of arachnoid membrane
Follows dura mater into Dural sleeves and caudally into Dural sac
The spinal cord begins at the
Foramen Magnum just inferior to brain stem
Dura mater extends from
From the foramen magnum to s2 level of vertebral canal
Lateral cutaneous branch
Goes to skin. Only sensory. (No motor fibers bc no muscle in skin)
Is composed of neuronal cell bodies (neurons) and glial cells bodies.
Gray matter
Spinal cord comprised of what 2 sections
Gray matter and white matter
ventral horn (anterior horn)
Motor region
conus medullaris
Narrowed end of spinal cord
somatosensory neuron
Neuron that carries information from the skin to the spinal cord
Do Anterior and posterior radicular a. merge with longitudinal a. ?
No.
radiculopathy of the ventral root
Only motor loss
radiculopathy of the dorsal root
Only sensory loss
Posterior vertebral artery via
Posterior inferior cerebellar aorta
Name change for dorsal ramus in posterior trunk
Primary ramus of t3 etc etc etc
Beginning of parasympathetic nervous system
S2,s3,s4 2,3.4 get our junk off the floor
1/2 of preglangionic parasympathetic neurons are located at these levels + where are the other half located
S2,s3,s4. + other half are located in the brianstem associated with the vagus nerve)
Conus medullaris aligns with what spinal cord levels
Sacral and coccygeal
dorsal horn (posterior horn) of grey matter
Sensory region
Trunk nerves terminal branch merges or stay separate
Separate
The DRG contains
Somatosensory neurons
Lumbar puncture (spinal anesthesia) what meningeal space location
Subarachnoid space
What space in life is a potential space?
Subdural space
Epidural space
Superficial to dura mater. Contains fat and internal vertebral plexus that drains spinal cord
Anterior and posterior radicular a. Supply spinal nerve, dorsal and ventral roots. T or F
T
Segmental a. Join longitudinal a. T or f
T
There are only nerve roots in Dural sac T or F
T
epaxial muscles
The muscles located posterior to the spinal cord.
hypaxial muscles
The muscles that are located anterior to the spinal cord.
How do sacral parts of sc located at L1/L2 make it to their intervertebral foramen?
The nerve roots extend down
If the Filum terminale is broken what would happen
The sc would float in canal and would get various symptoms
Do Anterior and posterior radicular a. Branch from regional arteries? but not merge with longitudinal a.
Yes
Azygous vein
a large vein on the right side at the back of the thorax, draining into the superior vena cava.
parasthesia
abnormal sensation such as numbness and tingling
dorsal ramus
branches to posterior part of body. Both sensory and motor travel this way.
Below L1-L2, the vertebral canal is occupied by a bundle of spinal nerve roots called the:
cauda equina
ventral root
contains axons of motor neurons
Ventral root
contains axons of motor neurons heading out of ventral horn
dorsal root
contains axons of sensory neurons that head into dorsal horn
vertebral canal
contains the spinal cord
radiculopathy
disease of the nerve roots
Meninges
dura mater, arachnoid mater, pia mater
dural sac
ends at S2. Ends as a blind pouch.
epidural lumbar puncture anesthesia
epidural space
lumbar puncture (spinal tap)
examination of spinal fluid withdrawn via a needle inserted in between two lumbar vertebra into the subarachnoid space of the spine
denticulate ligaments
extensions of pia mater that secure cord to dura mater
Varicella Zoster Virus lives and expressed how
in DRG and is expressed by each dermatome strip that it Innervates
The internal vertebral plexus of veins where?
lies inside the vertebral canal in the epidural space
Myotome
muscle or group of muscles supplied by a specific spinal nerve
gray matter of spinal cord
nerve cell bodies arranged in a butterfly shape with anterior and posterior "horns"
intercostal nerves
nerves between the ribs
lumbar enlargement
nerves to pelvic region and lower limbs
The external vertebral plexus of veins lies
outside the vertebral canal
cervical enlargement
supplies nerves to the shoulder and upper limbs
filum terminale
thin thread of fibrous tissue at end of conus medullaris, attaches to coccygeal ligament
pia mater
thin, delicate inner membrane of the meninges Adherent to sc
Epineurium
tough fibrous sheath around a nerve
dura mater
tough, outermost layer of the meninges Tough mother
Shingles caused by
varicella zoster virus
arachnoid mater
weblike middle layer of the three meninges Small membrane No connections between arachnoid and dura
