Term
| Upper Motor Neurons Tracts/Descending motor tracts originate (have their cell bodies) in the 1) OR 2) |
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Definition
| cerebral cortex or brainstem |
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Term
| Upper Motor Neurons Tracts make synaptic contact either directly or via an interneuron with 1) 2) AKA 3) |
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Definition
| alpha and gamma motor neurons (lower motor neurons). |
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Term
| axon location: of Upper Motor Neurons are found in the 1) 2) 3) |
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Definition
| cerebrum, brainstem and spinal cord. |
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Term
| two groups of upper motor neuron tracts |
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Definition
| dorsolateral, ventrolateral |
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Term
| dorsolateral group = which tracts? |
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Definition
| (LATERAL CST, RUBROSPINAL TRACTS) |
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Term
| where is the dorsolateral group of tracts found? |
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Definition
| in the dorsal portion of the lateral funiculus of the spinal cord. |
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Term
| where do the dorsolateral tracts decussate |
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Definition
| decussate in the brainstem and thus control contralateral body musculature. |
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Term
| what do the dorsolateral tracts regulate |
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Definition
| regulate the activity of the distal musculature used for skilled voluntary movements |
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Term
| ventrolateral group of tracts include which tracts? |
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Definition
| (VESTIBULOSPINAL, MEDULLARY AND PONTINE RETICULOSPINAL, ANTERIOR CST) |
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Term
| where in the Spinal cord are the ventrolateral tracts found |
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Definition
| travel in the ventral funiculus of the spinal cord |
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Term
| which musculature does the ventrolateral group of tracts influence |
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Definition
| influences axial and proximal musculature. |
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Term
| do dorsolateral tracts influence contralateral or ipsalateral musculature |
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Definition
|
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Term
| do ventrol tracts influence contralateral or ipsalateral musculature |
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Definition
| tend to be ipsalateral or bi lateral |
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Term
| cell bodies of the lower motor neurons are in which horns of the sc? and which nerve nuclei |
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Definition
| ventral horn of the spinal cord and in the motor cranial nerve nuclei. |
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Term
| axons of lower motor neurons are in the |
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Definition
| ventral roots, spinal nerve, and peripheral nerve, or in the cranial nerves. |
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Term
| alpha motor neurons: synapse directly with |
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Definition
| skeletal muscle (extrafusal muscle fibers) |
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Term
| gamma motor neurons: synapse directly with |
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Definition
| intrafusal muscle fibers (skeletal muscle fibers that comprise the muscle spindle) |
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Term
| corticospinal tract cell bodies are in |
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Definition
| primary motor cortex, with some cells also found in the premotor and sensorimotor cortex. |
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Term
| where does the CST decussate and what percent decussate |
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Definition
medulla at the decussation of the pyramids.
85% to 95% of the axons of the tract cross in this decussation. |
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Term
| the fibers of the CST that decussate become |
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Definition
| Lateral Corticospinal tract |
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Term
| LCST is found where in the cord? |
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Definition
| dorsal part of the lateral funiculus |
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Term
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Definition
| controls voluntary, skilled movements of the distal extremities (especially fractional movement of hands) |
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Term
|
Definition
| Alpha and Gamma motor neurons that innervate muscles of the distal extremities (e.g. hands). |
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Term
| part of which group of tracts |
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Definition
|
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Term
| organization: in cerebral cortex lower body info is _______ but in SC info is more______ |
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Definition
somatotopic: medial
lateral. |
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Term
| the uncrossed fibers of the CST are called the |
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Definition
| Ventral Corticopsinal tract |
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Term
| ventral corticospinal tract travels where? |
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Definition
| travel in ventral funiculus of the spinal cord |
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Term
| which group of tracts is the ventral corticospinal tract a part of? |
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Definition
| part of the "ventromedial group" of upper motor neuron tracts. |
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Term
| function of ventral corticospinal tract? |
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Definition
| assists other motor tracts in regulating axial body musculature. |
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Term
excites lower (alpha and gamma) motor neurons that: 1) innervate____
2) inhibit_____ |
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Definition
flexor muscles
inhibit extensor muscles. |
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Term
Corticobulbar Fibers
axons of the corticospinal tract that do not descend into the spinal cord. Leave tract in the ________ |
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Definition
| brainstem (bulbar refers to the brainstem) |
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Term
| corticobulbar fibers synapse in which nuclei?_____ with LMNs that innervate______ |
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Definition
cranial nerve nuclei
the facial muscles. |
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Term
| corticobulbar fibers regulate muscles of |
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Definition
| facial expression, mastication (chewing), speech, and eye movements. |
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Term
| Corticobulbar fibers that innervate the portion of the facial motor nucleus that activates the upper two thirds of the face are_______ |
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Definition
|
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Term
| corticobulbar fibers innervating the lower-face portion of the facial nucleus are________ |
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Definition
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Term
| a stroke that damages the corticobulbar fibers on one side of the brain will result in paralysis of the ________ facial muscles in the lower third of the face but produce ______in the upper face muscles |
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Definition
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Term
| the rubrospinal tract originates in the |
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Definition
|
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Term
| the red nucleus is involved in |
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Definition
|
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Term
| the rubrospinal tract is located |
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Definition
| adjacent to LCST in dorsal portion of lateral funiculus |
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Term
| the rubrospinal tract is a part of which group? the controls what? |
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Definition
| Dorsolateral group (deals with distal extremities) |
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Term
| the function of the rubrospinal tract is debated. it is thought |
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Definition
| to assist in the regulation of voluntary movements of the distal extremities |
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Term
|
Definition
| decussates in the brainstem |
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Term
| the rubrospinal tract is_________ organized |
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Definition
|
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Term
excites alpha and gamma motor neurons to physiological ______ muscles
inhibits lower motor neurons that innervate physiological ______. |
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Definition
|
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Term
| vestibulospinal tract originates |
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Definition
| in the vestibular nuclei in the medulla and pons |
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Term
| the vestibulospinal tract is located in the |
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Definition
| ventral (anterior) funiculus of the spinal cord |
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Term
| the vestibulospinal tract is part of the |
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Definition
| ventromedial group of tracts. |
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Term
| the vestibulospinal tract receives info. from the _________ and produces automatic_________ in response to changes in _____ _______, acceleration and direction of________ _______ |
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Definition
vestibular apparatus
head position
gravitational pull. |
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Term
vestibulospinal tracts mediate the reflexes for _______ and _______.
also called the _______ reflexes |
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Definition
balance and equilibrium (
labyrinthian reflexes-assist us in maintaining an upright posture. |
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Term
| the vestibulospinal tract adjusts the tone of the _____________ muscles |
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Definition
|
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Term
| the vestibulospinal tract adjusts the tone of the _____________ muscles |
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Definition
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Term
the vestibulospinal tract is ipsi vs. contra
the vestibulo is_______ organized |
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Definition
ipsilateral
somatotopically organized |
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Term
| the vestibulospinal tract innervates extensor vs flexor muscles |
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Definition
|
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Term
| the Vestibulospinal Tract along with the pontine reticulospinal tract are thought to be involved in _______ ______ reflexes |
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Definition
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Term
| the vestibulospinal tract (along with reticulospinal tract) is involved in _______ rigidity |
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Definition
|
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Term
| decerbate rigidity: excess ton in the _______ muscles. resulting in inc. tone in ______ of legs and ______ of arms. |
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Definition
antigravity muscles
extensors of the legs
flexors of the arms. |
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Term
| activity of vestibulospinal tract and reticulospinal tract are tonically inhibited by input form the _________________ |
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Definition
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Term
| If cortical input to the vestibulospinal and reticulospinal tract is removed by some pathological process or trauma, the tracts may be overactive which may result in increased muscle tone in the __________and _____ extensors. |
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Definition
| proximal and axial extensors. |
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Term
| the Pontine Reticulospinal Tract is also called the |
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Definition
| (medial reticulospinal tract) |
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Term
| the pontine/medial reticulospinal tract is located in the _______ funiculus and is part of the _______ group of tracts |
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Definition
ventral funiculus
ventromedial group of tracts. |
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Term
| pontine/medial reticuspinal tract orginate in the ______________________ |
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Definition
| pontine reticular formation |
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Term
| network of pathways and nuclei throughout the brainstem, connecting motor nerves and sensory nerve to and from the spinal cord, the cerebellum, and the cerebrum) |
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Definition
| pontine reticular formation |
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Term
| pontine/ medial reticulospinal tract AND medullary/reticulospinal tract |
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Definition
| regulate gross, unskilled, voluntary movements (e.g. walking, swimming, riding a bike). |
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Term
| thought to be important in making voluntary postural adjustments that precede and are associated with less skilled movements. |
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Definition
| pontine/ medial reticulospinal tract AND medullary/reticulospinal tract |
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Term
| innervate the proximal and, to a somewhat lesser extent, the axial body musculature |
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Definition
| pontine/ medial reticulospinal tract AND medullary/reticulospinal tract |
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Term
Stimulation of the pontine reticulospinal tract excites LMNS that innervate physiological_______muscles
and inhibit ________ muscles |
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Definition
|
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Term
| pontine/ medial reticulospinal tract ipsi vs contra? somatotopically organized? |
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Definition
ipsilateral
probably not somatotopically organized. |
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Term
| activity of the potine/medial reticulospinal tract, like that of all the other upper motor neuron tracts that have their origins (cell bodies) in the brainstem, is regulated by the ___________ |
|
Definition
|
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Term
| Medullary Reticulospinal Tract aka |
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Definition
| (lateral reticulospinal tract) |
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Term
medullary/ lateral reticulospinal tract
originates in the |
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Definition
| reticular formation in the medulla |
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Term
| medullary/ lateral reticulospinal tract is located in the ______portion of the ______ funiculus |
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Definition
| located in the most lateral portion of the ventral funiculus |
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Term
| medullary/ lateral reticulospinal tract is part of which group of tracts? |
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Definition
| part of the ventromedial group of tracts |
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Term
medullary/ lateral reticulospinal tract is ispi vs bi vs contr?
is is somotatopically organized? |
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Definition
bilateral
probably not somatotopically organized |
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Term
medullary/ lateral reticulospinal tract excite LMNs that innervate_______ muscles
and inhibit _________ |
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Definition
flexor muscles
inhibit extensors. |
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Term
MEDULLARY INNERVATE_____________
PONTINE INNERVATE________ |
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Definition
|
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Term
| ______ _____are at the top of the hierarchy of the regions of the nervous system that regulate movement. |
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Definition
|
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Term
| three motor regions of the cortex: |
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Definition
1) the primary motor cortex,
2) the premotor cortex, and
3) the supplementary motor cortex. |
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Term
Primary Motor Cortex is located in Brodmann's area__________ as is commonly known as ________
commonly known as the precentral gyrus. |
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Definition
located in Brodmann's area 4
precentral gyrus. |
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Term
| Many of the neurons that form the _______tract have their cell bodies in the primary motor cortex. |
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Definition
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Term
| primary motor cortex functions to regulate musculature of _____________________ |
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Definition
| distal extremities to produce fine, skilled, voluntary movements. fractional movements. |
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Term
Deficits Produced by Damage of Primary Motor Cortex: result in ______________
OR ________ |
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Definition
results in contralateral hemiplegia (paralysis in one half of the body)
OR hemiparesis (weakness in one half of the body).
most common cause of hemiplegia is stroke. |
|
|
Term
The typical stroke posture and gait include (contralateral to the damaged cortex):
1. a (flexed vs. extended) arm, wrist, and fingers
2. extension of the leg at the (1,2, 3)
3. lateral rotation of the leg
4. walking via ________ of the leg utilizing proximal body musculature
5. a positive ________ sign (______and _______ of the toes when a sharp object is run down the side of the foot)
6. (inc vs decr) muscle tone
7. unusual "tightness" of muscles =______
8. (hyper vs hypo )active reflexes |
|
Definition
1. a flexed arm, wrist, and fingers
2. extension of the leg at the hip, knee, and ankle
3. lateral rotation of the leg
4. walking via circumduction of the leg utilizing proximal body musculature
5. a positive Babinski sign (extension and fanning of the toes when a sharp object is run down the side of the foot)
6. increased muscle tone
8. hyperactive reflexes |
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Term
Premotor Cortex: located in Brodmann's area___
anterior to the __________. |
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Definition
Brodmann's area 6,
the primary motor cortex. |
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Term
| 2 motor functions have been ascribed to the premotor cortex. |
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Definition
-visually (or externally guided) guided hand movements (movements toward a target)
-regulates proximal and axial musculature, gait, interlimb coordination, and postural set |
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|
Term
| the premotor cortex exerts particular influence over which 2 ----spinal tracts? |
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Definition
| influence on the pontine and medullary reticulospinal tracts. |
|
|
Term
Deficits Produced by Damage to the premotor cortex:
1) on one side
2)bilateral damage
gait and posture, difficulty with |
|
Definition
1)may be no clear motor deficits when only one side of the premotor cortex is damaged
2)gait and posture,
difficulty with interlimb coordination, weakness in proximal musculature.
apraxia, which is difficulty performing learned movements. |
|
|
Term
Supplementary Motor Cortex is located in Brodmann's area ______________________
(mesial cortex anterior to the primary motor cortex) |
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Definition
Brodmann's area 6a alpha and 6a beta
(mesial cortex anterior to the primary motor cortex) |
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|
Term
Supplementary motor cortex is involved in
_____________________________
the supp cortex is thought to be important in movements that require extensive sensory guidance.
ie.reaching for an object around a plexiglass wall.
thought to influence movement through its interactions with the ________________________ |
|
Definition
involved in the conception, preparation for, and initiation of a movement.
thought to be important in movements that require extensive sensory guidance,
ie.reaching for an object around a plexiglass wall.
thought to influence movement through its interactions with the primary and premotor cortices, the basal ganglia, and the cerebellum. |
|
|
Term
Deficits Produced by Damage to supplementary motor cortex
may result in
the lost function will return if the damage is_________ |
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Definition
1)akinesia: literally translated as "without movement", inability to initiate movements even though all the upper motor neurons tracts are intact.
different than paralysis(results from damage to either upper or lower motor neurons and is defined as the inability to move the affected muscle groups.
2)may result in difficulty performing complex movements requiring sensory guidance and -difficulty in performing movements that require bimanual coordination. |
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Term
What do each of these trasmit?
[image] |
|
Definition
Dorsal roots carry information from the periphery to the central nervous system (CNS) in an afferent direction: generally sensory in nature.
Ventral roots carry information from the CNS to the periphery in an efferent direction. includes muscular contraction as well as gland secretion, hormone synthesis,
ventral horn contains the motor neurons
ventral roots carry information from the CNS to the PNS (efferent direction) includes signals to trigger muscular contraction as well as gland secretion, hormone synthesis, etc.
spinal nerve generally refers to a mixed spinal nerve, |
|
|
Term
| if the dorsal root of a spinal nerve were severed it would lead |
|
Definition
| to numbness in certain areas of the body. |
|
|
Term
| ventral roots(or anterior root) if cut it will lead to |
|
Definition
| to a kind of paralysis called flaccid paralysis. |
|
|
Term
Lower Motor Neurons (alpha and gamma motor neurons)can be damaged in the:
4 places |
|
Definition
1)ventral horn of the spinal cord
2) the ventral roots
3) the spinal nerves (this will also damage sensory axons)
4)peripheral nerves (this will also damage sensory axons). |
|
|
Term
signs of lower motor neuron damage
1) result mainly from damaging the (alpha vs gamma) motor neurons
2) tend to be (more or less) localized than signs of upper motor neuron damage
3) always observed (ipsilateral vs contra) to the lesion. |
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Definition
1) alpha
2)more localized
3) ipsilateral |
|
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Term
| signs of lower motor neuron damage. name 5 |
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Definition
1. flaccidity
2. paralysis or paresis
3. hyporeflexia
4. hypotonia
5. muscle atrophy due to loss of trophic factor and disuse |
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|
Term
Upper Motor Neuron Lesions can occur in the:
4 places |
|
Definition
motor cortex
internal capsule
brainstem
spinal cord |
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|
Term
| signs of upper motor neuron damage occur on which sides and in which cases depending on location of lesion |
|
Definition
contralateral if they occur above the decussation of the pyramids
ipsilateral if they occur in the spinal cord. |
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|
Term
Upper motor neuron damage will result in:
6 things |
|
Definition
1.spasticity- An increased resistance to passive movement of the limbs will be observed in one direction of movement only (typically resistance to flexion of the lower limb and extension of the upper limb).
2. paralysis or paresis (partial loss of movement, or impaired movement)
3.hyperreflexia-spasticity and exaggerated stretch reflexes result from
the loss of inhibitory influence that some of the upper motor neuron tracts have on spinal cord reflexes
4. hypertonia- results from exaggerated stretch reflexes
5. less muscle atrophy than with LMNs results from disuse
6. Babinski sign- extension and fanning of the toes on the affected side when a sharp object is run along the side of the foot |
|
|
Term
| all UMN deficits occur where in regards to the level of the lesion? |
|
Definition
| all deficits occur in the region below the level of the lesion |
|
|
Term
| a transient period of flaccid paralysis, called ___________ precedes the appearance of the upper motor neuron signs. |
|
Definition
|
|
Term
Complete Transection of the Spinal Cord
A) Sensory Deficits______________
B) Motor Deficits name 4 |
|
Definition
a. loss of all sensory modalities below the level of the lesion. both sides.
1. loss of all voluntary movement below the level of the lesion (paralysis)
2. spasticity
3. hyperreflexia
4. hypertonia |
|
|
Term
If transection is in in cervical spinal cord, all limbs will be affected . patient=.
if transection is Below the cervical cord, only the lower limbs will be affected. patient = |
|
Definition
patient= quadriplegic.
=paraplegic. |
|
|
Term
| Hemisection of the Spinal Cord aka__________ |
|
Definition
|
|
Term
Sensory Deficits of hemisection/ Brown Sequard Syndrome
1. contralateral loss of: (3)
2.ipsilateral loss of: (3) |
|
Definition
1. contralateral loss of pain, temp., and crude touch below lesion
2.ipsilateral loss of discriminative touch, vibration, and proprioceptive information below the level of the lesion |
|
|
Term
| Motor Deficits of hemisection/ brown sequard syndrome: ipsi vs contra? name 5 |
|
Definition
1. ipsilateral upper motor neuron deficits
-paralysis
-spasticity
-hyperreflexia
-hypertonia
-eventual atrophy |
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