Term
| List the Ascending Pathways |
|
Definition
1. Dorsal Column/Medial Lemniscus
2. Anterolateral
3. Spinocerebellar
-Dorsal Spinocerebellar
-Cuneocerebellar
-Ventral Spinocerebellar
-Rostral Spinocerebellar |
|
|
Term
| List the Descending Pathways |
|
Definition
1. Corticospinal
- Lateral Corticospinal
- Anterior Corticospinal
- Corticobulbar
2. Tectospinal
3. Rubrospinal
4. Reticulospinal
- Pontine (medulla) reticulospinal
- Medullary (lateral) reticulospinal |
|
|
Term
| Transmits impulses concerned with specific sensory modalities ultimately to the cerebral cortex for conscious perception or to the cerebellum for unconscious perception. |
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Definition
|
|
Term
| Where information is sent for conscious perception. |
|
Definition
|
|
Term
| Where information is sent for unconscious perception. |
|
Definition
|
|
Term
| Plays a role in regulating muscle tone and coordination of motor function. |
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Definition
| Conscious and unconscious perception |
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|
Term
| This pathway carries information concerned with touch, pressure, kinesthesia, vibratory sense, and 2 point discrimination |
|
Definition
|
|
Term
| Name the sensory receptors involved in the DC/ML pathway. |
|
Definition
Pacinian Corpuscles
Joint Receptors
Meissner's Corpuscles
GTOs
Muscle Spindles |
|
|
Term
| This pathway has most of the sensory receptors...except free nerve endings. |
|
Definition
|
|
Term
| This pathway starts at the Dorsal Root Ganglion and ends at the somatosensory cortex in the parietal lobe. |
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Definition
|
|
Term
| ___ processes of DRG cells provide axons to the sensory receptors in the DC/ML pathway. |
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Definition
|
|
Term
| Pick up information from the receptors and transmit information to the spinal cord. |
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Definition
|
|
Term
| ___ processes of the DRG cells enter the spinal cord by curving medially around the posterior horn and entering the posterior funiculus. |
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Definition
|
|
Term
| Ascending fibers from caudal segmental levels shift __ and ___ as they ascend in the posterior funiculus. DC/ML pathway. |
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Definition
|
|
Term
| As fibers from higher levels of the cord enter the posterior funiculus, they assume a position more ___. |
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Definition
|
|
Term
| An organizational route from when fibers enter the spinal cord to where they get to the cortex. |
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Definition
|
|
Term
| With somatotopic organization, the sacral fibers of the posterior funiculus are most __. |
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Definition
|
|
Term
| With somatotopic organization, the lumbar and thoracic fibers of the posterior funiculus are most __. |
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Definition
|
|
Term
| With somatotopic organization, the cervical fibers of the posterior funiculus are most __. |
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Definition
|
|
Term
| The posterior funiculus on each side i divided by the posterior intermediate septum above T6 into 2 separate funiculi. Name Them. |
|
Definition
Fasciculus Gracilis
Fasciculus Cuneatus |
|
|
Term
| Where is there a posterior intermediate septum present? |
|
Definition
|
|
Term
| This fasciculus is present in all spinal levels. |
|
Definition
|
|
Term
| This fasciculus is present at only T6 and above. |
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Definition
|
|
Term
| This fasciculus contains long ascending branches of fibers from sacral, lumbar, and lower thoracic dorsal roots. |
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Definition
|
|
Term
| This fasciculus contains long ascending branches of fibers from the upper 6 thoracic and all cervical dorsal roots. |
|
Definition
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|
Term
| Neurons in __ send their central processes ascending in the fasciculus gracilis and cuneatus are considered to constitute the 1st order neuron for the DC/ML pathway. |
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Definition
|
|
Term
| Neurons in the DRG send their central processes ascending in the gracilis and cuneatus are considered to constitute what? |
|
Definition
| 1st order neurons for DC/ML pathway |
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|
Term
| Fibers in the fasciculus gracilis and cuneatus ascend ___ |
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Definition
|
|
Term
| Where do the fibers in the gracilis and cuneatus terminate? |
|
Definition
on relay neurons in the medulla
(nucleus gracilis and nucleus cuneatus) |
|
|
Term
| What do nucleus gracilis and nucleus cuneatus give rise to? |
|
Definition
|
|
Term
| Sweep ventromedially as internal arcuate fibers |
|
Definition
| 2nd order neurons of DC/ML pathway |
|
|
Term
| The internal arcuate fibers of the DC/ML pathway decussate and form a compact fiber bundle located on each side of the brain stem. These bundles are known as what? |
|
Definition
|
|
Term
| Another Term for posterior |
|
Definition
|
|
Term
| Another term for Anterior |
|
Definition
|
|
Term
| The medial lemniscus ascends through the contralateral half of the brain stem, and its fibers terminate where? |
|
Definition
| In the VPL (Ventral Posterolateral) nucleus of the thalamus |
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|
Term
| From the VPL of the thalamus, ___ sends fibers to the postcentral gyrus of the cerebral cortex. |
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Definition
|
|
Term
| 3rd order neurons send fibers where? |
|
Definition
| To the Postcentral gyrus of the cerebral cortex |
|
|
Term
| Where is the postcentral gyrus of the cerebral cortex? |
|
Definition
| Parietal Lobe/Somatosensory cortex |
|
|
Term
| Lesions involving posterior columns diminish or abolish what? |
|
Definition
2 point discrimination
kinesthetic sense |
|
|
Term
| What is impaired when you have loss of position sense in the LE's? |
|
Definition
|
|
Term
| Loss of position sense in the LE's results in __. |
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Definition
|
|
Term
| Information from what pathway passes through the thalamus through the posterior limb of the internal capsule, then onto the parietal lobe? |
|
Definition
|
|
Term
| A group of pathways that trasmits nondiscriminative touch, temperature, and pain. |
|
Definition
|
|
Term
| Name the main pathway and the other fibers of the Anterolateral System. |
|
Definition
Spinothalamic Tract
-Spinomesencephalic
-Spinoreticular
-Spinohypothalamic |
|
|
Term
| Carries pain to the cerebral cortex to help you identify, localize, and characterize pain. |
|
Definition
|
|
Term
| This tract contains peripheral receptors of free nerve endings of A-delta and C fibers. |
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Definition
|
|
Term
| Are A-delta and C fibers slow or fast moving in response? |
|
Definition
| Slow compared to information about muscle stretch. |
|
|
Term
| 1st order neuron of the spinothalamic tract |
|
Definition
|
|
Term
| 2nd order neuron of the spinothalamic tract |
|
Definition
| dorsal horn lamina I, II, IV |
|
|
Term
| 3rd order neuron of the spinothalamic tract |
|
Definition
| VPL nucleus of the thalamus |
|
|
Term
| Where do axons of the 1st order neurons enter? |
|
Definition
| Dorsolateral Fasciculus (Lissauer's Tract) |
|
|
Term
| Axons of this may enter the dorsal horn or travel up the cord 1-5 segments then enter the dorsal horn. |
|
Definition
|
|
Term
| In what order neuron does the decessation occur in the spinothalamic tract? |
|
Definition
|
|
Term
| The axons cross where in the spinothalamic tract? |
|
Definition
| anterior white commissure |
|
|
Term
| After the axons cross in the anterior white commissure, where do they ascend? |
|
Definition
| in the cord contralateral anterior and lateral funiculi |
|
|
Term
| One or more extra neurons may be involved prior to the crossing in the anterior white commissure in what tract? |
|
Definition
|
|
Term
| Where does the spinothalamic tract terminate? |
|
Definition
| in the primary somatosensory cortex of the contralateral cerebral hemisphere and a few other areas of the brain |
|
|
Term
| What does the spinothalamic tract mediate? |
|
Definition
| Pain, temperature, non-discriminatory touch |
|
|
Term
| Does the spinothalamic tract help mediate dull, vague pain or sharp, well-localized pain? |
|
Definition
| Sharp, well localized, fast, pain. |
|
|
Term
| Where does the spinomesencephalic fibers terminate? |
|
Definition
| in the superior colliculi and PAG |
|
|
Term
|
Definition
|
|
Term
| These fibers are involved in turning the eyes toward the site of pain and activating descending tracts that control pain. |
|
Definition
|
|
Term
| What does the superior colliculi do? |
|
Definition
|
|
Term
| What does PAG in the midbrain do? |
|
Definition
| activates descending tracts that inhibit pain |
|
|
Term
| Where do spinoreticular fibers terminate? |
|
Definition
| In the reticular formation of the brain |
|
|
Term
| A group of nuclei in the brainstem that are involved in arousal and alertness. They govern sleep/wake cycles. |
|
Definition
| Reticular Formation in Brain |
|
|
Term
| Where do spinohypothalamic fibers terminate? |
|
Definition
|
|
Term
| These fibers mediate emotional and autonomic responses to pain. |
|
Definition
|
|
Term
| Lesions of the spinothalamic tract cause what? |
|
Definition
|
|
Term
| Will a lesion to the spinothalamic tract cause loss of touch? |
|
Definition
|
|
Term
| Will a lesion to the spinothalamic tract cause loss of temperature sensation? |
|
Definition
| Yes on the contralateral side |
|
|
Term
| If you had a lesion at C7 on the Left side. Where do you lose sensation? |
|
Definition
| Around T1 on the Right side because you lose pain sensation 1-2 segments below the actual lesion. |
|
|
Term
| Gray matter located around the cerebral aqueduct |
|
Definition
|
|
Term
|
Definition
|
|
Term
| __ has neurons that have opiate receptors that sends axons down to raphe nuclei in the medulla. |
|
Definition
|
|
Term
|
Definition
|
|
Term
| In the descending pain inhibitory pathway, PAG are opiate receptors that project to the raphe nuclei, then the raphe cells project to laminae __ and __ of the spinal cord. |
|
Definition
|
|
Term
| In the descending pain inhibitory pathway, once the raphe cells project to the lamina II and III in the spinal cord, there is activation of what type of neurons in the laminae II and III. |
|
Definition
|
|
Term
| In the descending pain inhibitory pathway, activation of enkephalinergic neurons inhibit what? |
|
Definition
|
|
Term
| Instead of the descending pain inhibitory pathway going thru all the steps, where can it go via direct connection? |
|
Definition
|
|
Term
| Blocks pain along the anterolateral pathway. |
|
Definition
|
|
Term
| Where in the spinal cord are enkephalinergic neurons located? |
|
Definition
|
|
Term
| Give an example of opiates being given locally. |
|
Definition
|
|
Term
| This type of opiate is produced by the body. |
|
Definition
| Endogenous Opiates (Endorphins) |
|
|
Term
| What type of opiates are ingested? |
|
Definition
|
|
Term
| Name 3 endogenous opiates (endorphins) |
|
Definition
Enkephalins
Dynorphin
B-Endorphin |
|
|
Term
|
Definition
|
|
Term
| Why are exogenous opiates dangerous? |
|
Definition
|
|
Term
| Activates neurons with opiate receptors in PAG, raphe, and dorsal horn. |
|
Definition
|
|
Term
| Opiates cause analgesia which is accompanied by what? |
|
Definition
|
|
Term
| What does TENS stand for? |
|
Definition
| Transcutaneous Electrical Nerve Stimulation |
|
|
Term
| Activates large-diameter myelinated fibers (somatosensory fibers) |
|
Definition
|
|
Term
| With TENS, the collaterals from the large-diameter fibers stimulate what? |
|
Definition
| enkephalinergic interneurons in the dorsal horn |
|
|
Term
| In TENS, when the enkephalinergic interneurons at released, this inhibits the release of what and helps block pain transmission? |
|
Definition
|
|
Term
| Delivers electrical stimulus to control pain. |
|
Definition
|
|
Term
| Pain from visceral structures perceived as arising from superficial structures such as skin, bone, or muscle. |
|
Definition
|
|
Term
| Pain that arises from skin, bone, or muscle. |
|
Definition
|
|
Term
| Name a few visceral structures. |
|
Definition
| Gut, heart, gallbladder, kidney, etc. |
|
|
Term
| How is visceral pain transmitted. |
|
Definition
|
|
Term
| Visceral pain is typically referred to ___ structures whose afferents enter the cord via the same dorsal roots. |
|
Definition
|
|
Term
| Visceral pain fibers may synapse on and activate what? |
|
Definition
|
|
Term
| Normally transmit somatic pain |
|
Definition
|
|
Term
| Once the dorsal horn tract cells are activated, the pain information travels along the ___ pathway |
|
Definition
|
|
Term
| Because visceral pain travels along the somatic pathway, what does the pain sensation feel like. |
|
Definition
| Somatic rather than visceral |
|
|
Term
| What may make the true origin of the pain source |
|
Definition
|
|
Term
| Visceral pain fibers are ___ |
|
Definition
|
|
Term
| Many patterns of referred pain are __ of visceral pathology |
|
Definition
|
|
Term
| If you have pain coming from the diaphragm, where might it refer to? |
|
Definition
|
|
Term
| If you have pain coming from the esophagus, where might it be referred to? |
|
Definition
|
|
Term
| If you have pain coming from the heart, where might it be referred to? |
|
Definition
| Left chest, shoulder, medial aspect of the left arm (T1-8) |
|
|
Term
| If you have pain from the stomach, where might it be referred to? |
|
Definition
|
|
Term
| If you have pain from the gallbladder, where might it be referred to? |
|
Definition
| Lower, anterior border of the right rib cage; mid-scapular area |
|
|
Term
| If you have pain from the appendix, where might it be referred to? |
|
Definition
|
|
Term
| If you have pain from the kidneys, where might it be referred to? |
|
Definition
| Left inguinal region; lumbar spine |
|
|
Term
| If you have a patient coming in with reports of pain what should you try to discern? |
|
Definition
| If it is referred or musculoskeletal |
|
|
Term
| Controls the ipsilateral side of the body in balance, movement control, and body position. |
|
Definition
|
|
Term
| An organ that provides unconscious control. |
|
Definition
|
|
Term
| 2 of these tracts serve the lower half of the body (T1 and below) and 2 of these tracts serve the upper half (Above T1) |
|
Definition
|
|
Term
| Name the 2 spinocerebellar tracts that serve the lower half of the body (T1 and below) |
|
Definition
DSCT Dorsal Spinocerebellar Tract
VSCT Ventral Spinocerebellar Tract |
|
|
Term
| Name the 2 spinocerebellar tracts that serve the upper half of the body (Above T1) |
|
Definition
Cuneocerebellar Tract
Rostral Spinocerebellar Tract |
|
|
Term
| Convey information concerning muscle length and changes in length, tension in tendons, and touch and pressure from the skin to the cerebellum for unconscious control of movments. |
|
Definition
|
|
Term
| Name the 4 receptors involved in the spinocerebellar tracts. |
|
Definition
GTOs
Muscle spindles
Touch receptors
Pressure receptors |
|
|
Term
| What are the sensory receptors for the DSCT? |
|
Definition
GTOs (Type Ib fibers)
Muscle Spindle (Type Ia and II fibers)
Touch and pressure receptors |
|
|
Term
| What is the 1st order neuron for DSCT |
|
Definition
|
|
Term
| In the DSCT, the DRG cells central processes goes into the spinal cord and synapse on the what? |
|
Definition
|
|
Term
| Another name for Nucleus Dorsalis |
|
Definition
|
|
Term
| What is the 2nd order neuron for DSCT? |
|
Definition
|
|
Term
| In what spinal levels can you find the Nucleus Dorsalis? |
|
Definition
|
|
Term
| Afferents below what level travel up in posterior columns to synapse on nucleus dorsalis neurons? |
|
Definition
|
|
Term
| Name 2 things that have an intermediolateral cell column. |
|
Definition
Nucleus Dorsalis
Lateral Horn |
|
|
Term
| What connects the cerebellum to the brainstem? |
|
Definition
| Inferior cerebellar peduncle |
|
|
Term
| A group of axons that connects one structure to another. |
|
Definition
|
|
Term
| A De-myelinating dizease with chances of a full recovery |
|
Definition
|
|
Term
| In the DSCT, neurons of the nucleus dorsalis give rise to large fibers that ascend in the posterolateral part of the what? |
|
Definition
|
|
Term
| In the DSCT, the fibers that ascend in the lateral funiculus become incorporated in what once they reach the medulla and terminate ipsilaterally in the cerebellum. |
|
Definition
| Inferior Cerebellar Peduncle |
|
|
Term
| This tract conveys proprioceptive information from the lower extremities. |
|
Definition
|
|
Term
| What are the sensory receptors for the Cuneocerebellar tract? |
|
Definition
Muscle Spindle
GTO
Touch and pressure receptors |
|
|
Term
| What is the 1st order neuron for the cuneocerebellar tract? |
|
Definition
|
|
Term
| In the cuneocerebellar tract, the DRG cells central processes travel in what to synapse on the 2nd order neurons in the lower medulla? |
|
Definition
|
|
Term
| Where is the 2nd order neuron of the cuneocerebellar tract located? |
|
Definition
| In the accessory (lateral) cuneate nucleus in the lower medulla |
|
|
Term
| Axons from the neurons in the cuneocerebellar tract enter the __ and terminate in the cerebellum ipsilateral to origin of tract. |
|
Definition
| Inferior Cerebellar Peduncle |
|
|
Term
| Name the spinocerebellar tract that deccussates twice. |
|
Definition
|
|
Term
| This tract carries unconscious sensation to the cerebellum from the lower 1/2 of the body and also transmits information being carried to the spinal cord from descending motor pathways. |
|
Definition
|
|
Term
| Name the sensory receptors for VSCT |
|
Definition
GTO
Muscle Spindle
Touch
Pressure
Descending motor pathways |
|
|
Term
| What is the 1st order neuron of VSCT |
|
Definition
| Cells in laminae V, VI, VII in the lumbar segments |
|
|
Term
| Axons from the neurons of VSCT deccussate immediately in what to form a tract in the contralateral anterior lateral funiculus. |
|
Definition
| Anterior White Commissure |
|
|
Term
| In the upper pons, the VSCT enters the what to reach the cerebellum? |
|
Definition
| Superior Cerebellar Peduncle |
|
|
Term
| After the VSCT has entered the cerebellum it crosses again in the cerebellum to terminate in the side of the cerebellum ipsilateral to the origin of the tract. TRUE/FALSE |
|
Definition
|
|
Term
| This tract conveys information related to attempted movement. |
|
Definition
|
|
Term
| What are the sensory receptors for the Rostral Spinocerebellar Tract? |
|
Definition
GTO
Muscle Spindle
Touch and Pressure receptors |
|
|
Term
| What is the 1st order neuron of the Rostral Spinocerebellar Tract? |
|
Definition
| Cells in the posterior horn of the cervical enlargement |
|
|
Term
| Axons from the cells of the Rostral Spinocerebellar Tract ascend uncrossed in what funiculus of the spinal cord? |
|
Definition
|
|
Term
| The cells of the rostral spinocerebellar tract travel to the ipsilateral cerebellum via what peduncles? |
|
Definition
| Inferior and Superior Cerebellar Peduncles |
|
|
Term
| The only pathway that originates in the cerebrum. |
|
Definition
|
|
Term
| Concerned with somatic and visceral motor (efferent) activities. |
|
Definition
|
|
Term
| Originate in the cerebral cortex or brainstem. Pathways that originate in the brainstem possess cortical control. |
|
Definition
|
|
Term
| Name the 2 pathways of the Corticospinal System. |
|
Definition
Lateral Corticospinal
Anterior Corticospinal |
|
|
Term
| This system consists of fibers that arise from cell in the cerebral cortex, pass through the internal capsule, and descend to the brain stem or spinal cord. |
|
Definition
|
|
Term
| Fibers in the brainstem that provide voluntary control over cranial nerves. |
|
Definition
|
|
Term
| Cerebral cortex to the corona radiata to the internal capsule to the brainstem or spinal cord. |
|
Definition
|
|
Term
| Where are neurons of the corticospinal system primarily located? |
|
Definition
| Lamina V in the primary motor cortex, the premotor and supplementary motor areas and the postcentral gyrus |
|
|
Term
| Mapping of the cerebral cortex in areas of functioning. |
|
Definition
|
|
Term
| What brodman's area is in the precentral gyrus |
|
Definition
|
|
Term
| What Brodman's area is in the premotor and supplementary motor areas. |
|
Definition
|
|
Term
| What Brodman's area is in the postcentral gyrus mainly |
|
Definition
|
|
Term
| TRUE/FALSE: Somatotopic organization of neurons within the primary motor cortex (motor humunculus). Somatotopy is maintained through the midbrain and may be disrupted thereafter. |
|
Definition
|
|
Term
| This system comes from the cerebral cortex, then fibers converge in the corona radiata and travel in the posterior limb (corticospinal) and genu (corticobulbar) of the internal capsule. |
|
Definition
|
|
Term
| The genu of the internal capsule holds what type of fibers? |
|
Definition
|
|
Term
| The posterior limb of the internal capsule holds what type of fibers? |
|
Definition
|
|
Term
| The the midbrain levels, the corticospinal fibers form the middle 1/3 of what? |
|
Definition
| Crus Cerebri (Cerebral Peduncles) |
|
|
Term
| Where are the corticobulbar fibers located in reference to the corticospinal fibers? |
|
Definition
|
|
Term
| In the pons, the fibers of the corticospinal system are broken up into scattered fiber bundles in what portion of the pons? |
|
Definition
|
|
Term
| Once the fibers of the corticospinal system reach the medulla, they come back together in what portion of the medulla? |
|
Definition
|
|
Term
| Around 80-90% of corticospinal fibers cross where? |
|
Definition
| at caudal meduallary levels (junction of medullar and spinal cord) |
|
|
Term
| Around 80-90% of corticospinal fibers cross at caudal medullary levels and enter what of the spinal cord? |
|
Definition
| The posterior part of the lateral funiculus |
|
|
Term
| Once the corticospinal fibers are in the spinal cord what do they form? |
|
Definition
| Lateral corticospinal tract |
|
|
Term
| This tract descend the length of the spinal cord giving off fibers to synapse on interneurons and motor neurons (a few) in the intermediate gray and anterior horn of the spinal cord at all levels of the spinal cord. |
|
Definition
| Lateral corticospinal Tract |
|
|
Term
| What does the lateral corticospinal tract control |
|
Definition
| Distal flexor musculature. Primarily in the hand but in the feet also. |
|
|
Term
| Twice as many axons from this tract terminate in the cervical as compared to the lumbar enlargement. |
|
Definition
| Lateral Corticospinal Tract |
|
|
Term
| The fibers from this tract remain uncrosses into the spinal cord and occupies the area of the anterior funiculus. |
|
Definition
| Anterior corticospinal tract |
|
|
Term
| Fibers from this tract do not cross until they reach the anterior white commissure where they will terminate on interneurons in the cord. |
|
Definition
| Anterior corticospinal Tract |
|
|
Term
| Present mainly in the cervical spinal cord. Controls axial musculature. |
|
Definition
| Anterior Corticospinal Tract |
|
|
Term
| Provides cortical innervation for motor nuclei of cranial nerves V, VII, X, XI, XII |
|
Definition
|
|
Term
| What does the tectum of the midbrain include? |
|
Definition
2 superior colliculi
2 inferior colliculi |
|
|
Term
| Neurons of this tract are located in the deep layers of the superior colliculus of the midbrain |
|
Definition
|
|
Term
| Name the 2 tracts that originate in the midbrain |
|
Definition
|
|
Term
| Where do axons from the tectospinal tract cross? |
|
Definition
| in the midbrain tegmentum just anterior to the PAG |
|
|
Term
| Once the neurons of the tectospinal tract cross where do they descend to? |
|
Definition
| medial longitudinal fasciculus (MLF) |
|
|
Term
| In the spinal cord, the tectospinal tract lies in what funiculus near the anterior median fissure? |
|
Definition
|
|
Term
| The tectospinal tract is present only in what levels of the spinal cord? |
|
Definition
|
|
Term
| Where do the majority of fibers terminate in the tectospinal tract? |
|
Definition
| Upper 4 cervical segments |
|
|
Term
| Fibers from this tract terminate on interneurons in the intermediate gray and anterior horn to influence the motor neurons of neck musculature. |
|
Definition
|
|
Term
| What is the function of the tectospinal tract? |
|
Definition
| To mediate reflexes turning the head in response to visual and probably auditory stimuli. |
|
|
Term
| This tract controls upper extremity flexors |
|
Definition
|
|
Term
|
Definition
|
|
Term
| The neurons of the rubrospinal tract come from where? |
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Definition
| the red nucleus of the midbrain |
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Term
| Axons from the rubrospinal tract come out of the red nucleus and immediately deccussate where before descending to the spinal cord? |
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Definition
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Term
| In the spinal cord, the rubrospinal tract lies anterior to the lateral corticospinal tract in the what? |
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Definition
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Term
| Is the rubrospinal pathway active on its own? |
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Definition
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Term
| This tract has intrinsic activity that occurs in the background when not needed |
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Definition
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Term
| In the rubrospinal tract, in the spinal cord, the neurons descend primarily to where? |
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Definition
| Cervical enlargement where it has the most influence |
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Term
| Natural facilitory influence modulated (inhibited) through cortical input (corticorubral fibers) |
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Definition
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Term
| Name the 2 reticulospinal tracts |
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Definition
Pontine (medial)
Medullary (lateral) |
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Term
| Groups of nuclei located throughout the brain stem |
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Definition
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Term
| These tracts arise from areas of the brain stem known as reticular formation |
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Definition
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Term
| Name 3 functions of the reticulospinal tracts. |
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Definition
1. Alternative pathways for control of spinal motor neurons
2. Regulate sensitivity of spinal reflexes
3. May initiate some movements |
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Term
| This tracts neurons come from the reticular formation of the pons. |
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Definition
| Pontine Reticulospinal Tract |
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Term
| The axons from this tract descends in the brainstem in association with the MLF. In the spinal cord, this tract lies in the medial part of the anterior funiculus. |
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Definition
| Pontine (medial) reticulospinal tract |
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Term
| Does the pontine reticulospinal tract cross or remain ipsilateral? |
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Definition
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Term
| Axons from this tract come from the reticular formation of the medulla, particularly the nucleus reticularis gigantocellularis. |
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Definition
| Medullary Reticulospinal Tract |
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Term
| Most fibers of this pathway remain uncrossed and descend in the anterior part of the lateral funiculi. |
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Definition
| Medullary (Lateral) Reticulospinal Tract |
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Term
| Motor neurons located in either the spinal cord or the cranial nerve motor nuclei. |
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Definition
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Term
| Anterior horn cells and their axons, projecting via the ventral root to striated muscle. |
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Definition
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Term
| Also referred to as the final common pathway |
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Definition
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Term
| Injury or disease of the anterior horn cells or projecting axons results in what 4 things? |
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Definition
1. Paralysis of muscles innervated by these fibers
2. Loss of muscle tone
3. Atrophy of denervated muscle
4. Hypoactive or absent myotatic reflexes in that segment or segments (hyporeflexia) |
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Term
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Definition
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Term
| Decreased to absent DTR's |
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Definition
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Term
| Neurons which are contained within descending motor pathways and influence the alpha motor neuron either directly or indirectly |
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Definition
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Term
| These motor neurons do not make connections with muscles but stay completely within the CNS |
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Definition
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Term
| Upper motor neuron lesions are characterized by what 5 things? |
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Definition
1. Paresis of muscles involved
2. Initial loss followed by increased muscle tone
3. Hyperactive myotatic (DTR) reflexes (hyperreflexia)
4. Positive Babinski Sign
5. Mild muscle atrophy not seen initially because segmental innervation of striated muscle remains intact |
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Term
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Definition
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Term
| If the corticospinal system is involved will you see a positive or negative babinski sign? |
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Definition
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Term
| Lesion to the brain stem in the area of the midbrain caudal to the red nucleus. Interrupts all descending motor pathways except the reticulospinal. Also interrups modulating influence from the cortex on pontine reticulospinal tract. |
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Definition
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Term
| What is the result of Decerebration? |
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Definition
| Decerebrate Rigidity - extensor posturing of all 4 extremities |
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Term
| Lesion rostral to the red nucleus. Leaves the rubrospinal tract intact while interrupting cortical modulation of the rubrospinal system. Still have increased activity of the reticulospinal system. |
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Definition
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Term
| What is the result of Decortication? |
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Definition
| Decorticate Rigidity - flexor posturing of UE and extensory posturing of LE |
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Term
| It is an ominous sign if the patient progresses from decorticate to decerebrate rigidity. Why? |
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Definition
| this is indicative of the level of damage to the CNS. This means that the area of lesion has spread below the red nucleus area |
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Term
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Definition
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