Lecture 41/42/43 - Spinal Cord Flashcards
where are the two enlargements of the spinal cord
- cervical (C6-T2)
- lumbar (L4-S3)
T/F: the dura mater around the brain is attached to the periosteum of the skull
TRUE
the spinal cord sits in what
cushion of epidural fat
T/F: as peripheral nerves leave the CNS there is no fusion of meninges with the epineurium
FALSE
what is the filum terminale
ependymal cells and meninges fused to the periosteum of the caudal vertebrae
where is the dorsal and ventral root of spinal nerves located
within the vertebral canal
where is the location of the spinal ganglion
intervertebral foramen
define:
nerve
collection of nerve processes (axons and dendrites)
define:
nerve root
collection of purely motor or sensory peripheral nerve processes before they form the nerve
define:
ganglion
collection of functionally similar nerve cell bodies
T/F: there is no synapse in the dorsal root or ganglion
TRUE
what job does the spinal ganglion and dorsal root have
sensory (afferent)
what is the job of neurons that reside in the ventral horn
motor (efferent)
what is the peripheral nerve proper
spinal nerve = sheath containing dorsal and ventral roots for mixed function
what fuses with the epineurium
dura mater and arachnoid
where do the nerve roots run
subarachnoid space and penetrate pia mater
cervical intumescence
- C6-T2
- nerves form brachial plexus
- innervate TL, cutaneous trunci, sympathetic supply to head
lumbosacral intumescence
- L4-S3
- nerves form lumbosacral plexus
- innervate PL, bladder, anus, tail
T/F: the vertebral column will continue to outgrow the spinal cord
TRUE
what is the cauda equina
terminal portion of the spinal cord in the vertebral canal (L6/7-S3) where nerve roots pass through the epidural space to appropriate IVF and exit canal
conus medullaris
S2-Cd5 = terminal portion of spinal cord
Case Study:
4m/o French Bulldog presents with fecal and urinary incontinence. no problem with motor function.
physical exam showed a divet of the lumbar spinal region
Hast MRI illustrated CSF penetrating vertebrae and mm.
Give the diagnosis, treatment, and prognosis
diagnosis: spina bifida w/ meningocele
tx: surgical removal of scar tissue
prognosis: no progressive damage, improved function
T/F: the number of paired spinal nerves is equal to the number of vertebrae in every spinal cord region
FALSE - in the cervical region it is # + 1
where do C2-C7 exit the vertebral canal
at the IVF cranial to vertebra of the same number
where do C8 nn. exit the vertebral canal
between C7 and T1
where do T1-Cd5 nn. exit the vertebral canal
at the IVF caudal to the vertebra of the same number
T/F: C1-T10 segments are located one vertebra ahead of the same number
TRUE
T/F: T11-L3 segments are located in one vertebra behind the same number
FALSE - within
where are L4-L7 segments located
L3/4
where are S1-S3 segments located
L5
where are Cd1-Cd5 segments located
L6
if you were to place a needle into the vertebral canal at L7/SI in a dog would you be able to sample CSF?
no - too caudal
what is the function of and origin of:
dorsal horn
sensory; alar plate
what is the function of and origin of:
ventral horn
somatic motor; basal plate
what is the function of and origin of:
lateral horn and intermediate zone
autonomic (sympathetic) motor; basal plate T1-L4
what is the function of and origin of:
intermediate zone
autonomic (parasympathetic) motor; basal plate S1-3
what does the lower motor neuron do
carry motor impulses from CNS to the peripheral target
what are the 5 components of reflexes
- receptor
- afferent neuron
- interneurons
- efferent neuron (LMN)
- target
what 4 components are involved in the stretch reflex
- straight patellar l.
- femoral nerve
- quadriceps m.
- L4-6 spinal cord segments
what nerve innervates the cutaneous trunci m.
lateral thoracic
what direction do nerves run to the cutaneous trunci? why may this be an issue?
caudally; mismatch of stimuli and response
damage to the LMN results in
-paresis or -plegia
T/F: damage to the reflex pathway will result in the reduction or loss of the reflex
TRUE
what other side effects may result from the damage to a reflex pathway
- reduction/loss of muscle tone
- neurogenic atrophy
what clinical score is considered normal for reflexes
+2
