Lecture 9 Flashcards
What nuclei is the 1st Rexed’s Laminae a part of?
Marginal layer nuclei
What nuclei is Rexed Laminae 2 a part of?
Substantia Gelatinosa
Which nuclei is the 3rd and 4th Rexed Laminae a part of?
Nucleus Proprius
Which Rexed Laminae is a part of the Clarke’s nucleus?
7
What nuclei is Rexed’s laminae IX a part of?
Motor Nuclei
Which Rexed’s Laminae does proprioception
3 and 4
Which Rexed Laminae does noxious stimuli
1 and 2
What layer of meninges does the CSF circulate between?
Subarachnoid
With flexion of the spine, the SC stretches __% wereas the cauda equina ____
Spinal Cord stretches 10%
Cauda Equina stretches very little
What tract is the only one which doesn’t get it’s signals modulated by the spinalcord, and instead ascends all the way to the medulla before synapsing
Dorsal Column
How does the Jendrassik maneuver alter the DTR
Decreases inhibition going down the spinal cord
What is the purpose of central pattern generator
Rhythmic motor patterns
With complete transection of spinal cord, the Stepping pattern generator (Central pathway generator) can only be activated by ____________
Artificial means
What is the crossed extension reflex?
Withdraw reflex of one leg will ilicit the opposite LE to extend and catch yourself before you fall
What is a Renshaw cell?
Inhibitory interneuron who inhibits agonist and disihibits antagonist to promote fine motor control
Opposite of a muscle spindle!
segmental vs vertical tract impairment
segmental - show dermatomal/myotomal pattern
vertical pattern- everything below the level of that lesion (ipsilateral or contralateral depending on the tract)
Reflexive bladder function requires what spinal levels?
Afferents: T11-L2 + S2-S4 cord levels
The frontal cortex inhibits the _____ from telling sacral urination center to empty
Pons
If the situation is appropriate the ______ disinhibits the ___ which will then signals to the sacral cord center to contract bladder walls
Frontal cortex disinhibits the pons
The sacral cord center signals _______ (parasympathetic or sympathetic) neurons to contract the bladder wall and relax the sphincter
Parasympathetic
Though the pons does not inhibit the bladder wall, it does send inhibitory signals to the __________
Alpha motor neurons of the external sphincter and pelvic floor muscles
Bladder filling is involuntary with _______ (sympathetic or parasympathetic) fibers telling the bladder wall to relax and the internal sphincter to contract
sympathetic
Parasympathetic does the opposite (Contracts bladder wall and relaxed sphincter)
How is the walking Stepping Pattern Generator normally activated?
Brain sends signal down spinal cord to let it know to start walking
For sexual function, Psychogenic processes are mediated by what spinal levels?
Psychogenic (thoughts) L1-L2
Reflexogenic (sensory) S2-S4
Nerve fibers that originate in L1-L2 with cell bodies in S2-S4 control orgasm
Where are the reflexogenic (sensory) fibers responsible for sexual function located
Psychogenic (thoughts) L1-L2
Reflexogenic (sensory) S2-S4
Nerve fibers that originate in L1-L2 with cell bodies in S2-S4 control orgasm
What is the location of sympathetic nerve fibers responsible for orgasm
Psychogenic (thoughts) L1-L2
Reflexogenic (sensory) S2-S4
Nerve fibers that originate in L1-L2 with cell bodies in S2-S4 control orgasm + pudendal nerve
What is Brown-Sequard syndrome
Exactly 1 half of the spinal cord is cut.
It manifests with weakness or paralysis and proprioceptive deficits on the side of the body ipsilateral (motor tracts+dorsal column) to the lesion and loss of pain and temperature sensation on the contralateral side (anteriolateral).
In Brown-Sequard syndrome, the dorsal column senses are affected (contralaterally/ipsilaterally)
Whereas the anteriolateral cord senses are effected (contralaterally/ipsilaterally)
Dorsal- Ipsilateral (note motor tracts are ipsilateral too)
Anteriolateral - Contralateral (Because this tract crosses immediately in the spinal cord)
How does anterior cord syndrome usually present?
Motor, Nociceptive, Temperature Impairments
What functions are typically preserved in anterior cord syndrome?
Proprioception and light touch
How and where does central cord syndrome usually occur?
Usually seen at cervical level following trauma
