true or false – the outer layer of the spinal cord is white matter
true
what color is interlayer of the spinal cord and why
Gray – it is not covered by myelin
the white matter is subdivided into how many layers?
three large areas– much like a telephone wire
what is a primary role of the spinal cord?
responsible for regulating many of our bodily functions throughout accending and descending pathways to and from the brain and intrinsic connections within the core itself
what is a cross-section of the spinal cord look like?
a butterfly
where do the cell bodies lie in the spinal cord
the Gray region
what is in the white matter of the spinal cord
axons that ascend and descend in the spinal cord
true or false – the vertebral column grows faster than the spinal cord
true
true or false – at birth the spinal cord ends at L2 – L3 level
true
in an adult where does the spinal cord end at?
L1
define spondylolisthesis
a forward slippage of the L5 vertebrae over the sacrum
what is it conus medullaris
the narrow end of the spinal cord
what is cauda equina mean?
the horses tail
what is filum terminale
terminal strand
The conus medullaris terminates as a thin non-nervous strand of tissue
where do the meninges terminate
S2 vertebral level
what are the three layers at the meninges?
dura mater
arachonoid
Pia Mater
what does dura mater mean
tough mother
what does arachonoid mean?
Spider like
what does pia mater mean?
delicate
true or false – the pia mater adheres to the spinal cord
true
the subarachnoid space contains what kind of fluid
cerebral spinal fluid
what is a lumbar cistern?
What is important about this site
the space between the end of the spinal cord L2 – L3 and the end of the dura S2
The site were lumbar puncture is performed to withdraw CSF
true or false – when the filum terminale reaches the end of the dural sac, it pierces the dura picking up an outer layer dura, and attaches caudally to the coccyx
true
the filum terminale ends and becomes
the cocygeal ligament
what is the role of the cocygeal ligament?
serves to anchor/tether the spinal cord
what structures anchor the spinal cord laterally?
denticulate ligaments – tooth like extensions of the Pia
how spinal nerves are there in the human body?
31 pairs
how many cervical spinal nerves are there
eight
true or false – C1 generally does not have a dorsal root, hence no C1 dermatome
true
how many thoracic nerves are there?
12
how many lumbar nerves are there
five
how many sacral nerves are there
five
true or false – there are always coccygeal nerve roots in the coccyx
false – there may be or may not be
true or false – the cervical nerve roots exit the intervertebral foramen at the level of there like named vertebrae
true
true or false – the thoracic, lumbar, and sacral roots end below the vertebrae of the same level
true
what are dermatomes?
dermatomes are a patch of dermis that is supplied predominantly by single dorsal root level
what is a myotome?
is a muscle or muscle group that is supplied primarily by a single central root level
where do sensory nerve fibers enter the spinal cord?
the posterior roots
what is found in the posterior/dorsal root ganglia?
the cell bodies of sensory nerve fibers
there are two enlargements in the spinal cord. What is this associated with?
the brachial plexus and the lumbosacral plexus
on the anterior surface of the spinal cord there is a deep grooves, what is the name of the structure?
anterior median fissure
the two shallow grooves that lie on either side of anterior median fissure are called________ ___________ _______
anterior lateral sulcus
what is a posterior intermediate sulcus?
is it shallow groove between the posterior median and posterior lateral sulcus. It is located above T7
in the gray region the cross-section looks like an _____ or _______ shape that stands out against the surrounding white matter
H or butterfly
how can the gray region to be divided?
anterior
posterior
lateral horns– seen only between T1-L2
the anterior cell columns consist primarily of what?
motor neurons
true or false – the medial motor nucleus innervates axial group muscles
true
what do the lateral motor nucleus innervate?
muscles of the extremities
in the anterior cell: the motor nerves that innervate extensor muscles lie more??????
anterior
in the anterior cells column, the motor nerves of the flexors are located more???
posteriorly
the posterior cell column, has three nuclear regions. What are they superficial to deep?
posteromarginal necleus
substantia gelatinosa
nucleus proprius
what is it nucleus dorsalis?
a structure that lies deep to the nucleus proprius that begins at C8-L2. It is located in the posterior cell column.
what is another name for the nucleus dorsalis?
Clarke's column
the substantial gelatinosa is thought to have a role in processing pain and?
temperature inputs from the periphery
what is the role of the nucleus proprius?
Functions in part to process proprioception
what is the nucleus dorsalis associated with?
the spinocerebellar pathways and receives input from large diameter afferent fibers associated with muscle and tendon sensory receptors (muscle spindles and gogli tendon organs)
