AAP Wiley Quiz 7 Spinal Cord and Nerves
Spinal cord extends from the foramen magnum of the skull to the first or second lumbar vertebrae, where it terminates in the ______.
conus medullaris
How many pairs of spinal nerves do we have?
31
List the pairs of spinal nerves?
8 cervical nerves
12 thoracic nerves
5 lumbar nerves
5 sacral nerves
1 coccyx nerve
The ventral rami of all spinal nerves except T2 through T12 form complex networks of nerves known as _____?
plexuses
The communication center that is a continuation of the brain.
spinal cord
The spinal cord extends from the _________ of the skull to the first or second lumbar vertebrae, where it terminates at the _________.
foramen magnum
conus medullaris
A fibrous extension of the conus medullarius covered by pia matter, extends even farther to attach to the posterior coccyx.
filum terminale
Saw toothed shelves of pia mater, secures the spinal cord to the dura matter.
denticulate ligaments
A lumbar puncture is usually performed _______.
below L3 into the spinal meninges that extend below the spinal cord
List the spinal meninges from thickest to thinest.
dura mater
arachnoid matter
pia mater
Where are the two enlargements located in the spinal cord?
cervical
lumbar
Why does the spinal cord have these two enlargements?
The nerves in these areas serve the upper and lower limbs.
Collection of spinal nerve roots.
cauda equina
Located in the center of the spinal cord and shaped like the letter H.
Gray Matter
Human spinal nerves contain both sensory and and motor so therefore they are considered ________.
mixed nerves
These plexuses primarily serve the __________________.
muscles and skin of the limbs
The subdivision of the peripheral nervous system (PNS) that regulates body activities that are generally not under conscious control.
autonomic nervous system
autonomic nervous system aka _______________
involuntary nervous system
somatic nervous system aka ____________
voluntary nervous system
The ANS has two major functional subdivisions: _______________
sympathetic and parasympathetic
Parasympathetic (Craniosacral):
Origin in the CNS (contains preganglionic cell body)
Brain stem nuclei of cranial nerves 3, 7, 9, 10
Spinal cord segments sacral nerves S2-S4
Parasympathetic (Craniosacral):
Location of ganglia (contains the postganglionic cell body)
Located close to the target organ (terminal ganglia) or within the wall of the target organ (intramural ganglia)
Parasympathetic (Craniosacral):
Axon Lengths
Long preganglionic axons
Short postganglionic axons
Parasympathetic (Craniosacral):
White and Grey Rami communication
None
Parasympathetic (Craniosacral):
Degree of branching of preganglionic axons
Minimal
Parasympathetic (Craniosacral):
Functional role
Performs maintenance functions; conserves and stores energy; rest-and-digest response
Parasympathetic (Craniosacral):
Neurotransmitters
Preganglionic axons release acetylcholine (cholinergic fibers)
Post ganglionic axons release acetylcholine
Parasympathetic (Craniosacral):
Effects of the division
more specific and local
Sympathetic (Thoracolumbar):
Origin in the CNS (contains the preganglionic cell body)
Lateral horns of the grey matter of the spinal cord T1-L2
Sympathetic (Thoracolumbar):
Location of ganglia (contains the postganglionic cell body)
Located close to the CNS, alongside the vertebral column (sympathetic trunk ganglia) or anterior to the vertebral column (collateral ganglia)
Sympathetic (Thoracolumbar):
Axon lengths
Short preganglionic axons
Long postganglionic axons
Sympathetic (Thoracolumbar):
White and grey rami communicates
Each white ramus communicans contains myelinated preganglionic axons
Each gray ramus communicans contains nonmyelinated preganglionic axons
Sympathetic (Thoracolumbar):
Degree of branching of preganglionic axons
extensive
Sympathetic (Thoracolumbar):
Functional role
Prepares the body for emergency situations and vigorous physical activity, fight-or-flight response
Sympathetic (Thoracolumbar):
Neurotransmitters
Preganglionic axons release acetylcholine
Sympathetic (Thoracolumbar):
Effects of the division
more general and widespread
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