12-2 DESCENDING NS Pathways Flashcards
<p>A: Cells of Origin for [Area 4 precentral gyrus] are called the \_\_\_\_ \_\_\_\_ \_\_\_\_. So...Corticospinal Tract is AKA \_\_\_\_ Tract B: CST starts in \_\_\_\_\_\_\_--->forms \_\_\_ \_\_\_\_--->which travels in Internal Capsule----> \_\_\_\_\_\_\_\_\_ --->\_\_\_\_\_\_\_\_ inside Pons -----> decusates in \_\_\_ \_\_\_\_\_---(travels in) -->\_\_\_\_ \_\_\_\_\_\_ as the \_\_\_\_\_\_\_\_---> synapse on [ANT horn cells] C1: 10% of CST fibers DON'T CROSS AT [\_\_\_ \_\_\_\_] These are called the \_\_\_\_ C2: These \_\_\_\_\_\_ cross over at diff levels of the \_\_ \_\_\_\_\_to still synapse on contralateral [ANT horn cells] like the \_\_\_\_\_\_\_\_\_ D: CST Fibers are \_\_\_\_[Upper/lower] Motor Neurons and is the \_\_\_[smallest/Largest] Descending Tract E: CST is used for what type of movements?</p>
<p>A: Cells of Origin for [Area 4 precentral gyrus] = [Pyramidal Betz Cells] (In the Medulla). So...Corticospinal Tract is AKA Pyramidal Tract B: CST starts in [Area 4 precentral gyrus]--->forms [CORONA RADIATA]--->travels in Internal Capsule----> [Crus Cerebri Cerebral Peduncle] --->[Base of the Pontine Gray] -----> decusates in medullary pyramid---(travels in)-->[Lateral funiculus] as the [Lateral CST]---> synapse on [ANT horn cells] C1: 10% of CST fibers DON'T CROSS AT [medullary pyramids= [ANT CST] . C2:[ANT CST] crosses over at diff levels of [Ventral Funiculus] to still synapse on contralateral [ANT horn cells] like the [Lateral CST] D: CST Fibers are Upper Motor Neurons and is the LARGEST Descending Tract E: CST is used for Fine movements like piano playing/picking up pennies</p>
[T or F] Cerebellar Lesions can be characterized as “Motor problems with NO Muscle Weakness”
TRUE!
<p>A: What does the CST synapse once it reaches \_\_\_ horn</p>
<p>B: Why 2 nuclei occupy the same space in the high cervical cord?</p>
<p>A: Synapse on Large [ANT horn cells] of medial and lateral motor nuclei of spinal cord Ventral Horn</p>
<p>B: Spinal Accessory nucleus (C1-C5) and Phrenic nuclei(C3,4,5) occupy SAME area in high cervical cord</p>
<p>1. Pyramidal Cells (of Area 4) are also called \_\_\_ Cells! These are the Cells of \_\_ Origin in the \_\_\_\_\_\_\_ -------------------------------------------------------------------------------------- 2. As CST axons come out of \_\_ \_\_\_\_ cells in the \_\_\_\_\_\_\_ they first form a Circular Crown called the \_\_\_ \_\_\_\_\_. This then travels in the \_\_\_\_\_\_ \_\_\_\_\_\_\_ \_\_\_ \_\_\_\_\_\_ and descends downward into the \_\_\_\_\_ of the \_\_\_----> \_\_\_\_\_\_\_ inside the Pons</p>
<p>1. Pyramidal Cells (of Area 4) are also called Betz Cells! These are the Cells of Motor Origin in Area 4.</p>
<p>2. As CST axons come out of [Pyramidal Betz Cells] in [Area 4 Precentral Gyrus] they form a Circular Crown= [CORONA RADIATA]. This then travels in the POSTERIOR LIMB>Internal Capsule and descends downward into the [Crus Cerebri Cerebral Peduncle] of Midbrain----> [Base of the Pontine Gray] inside Pons</p>
<p>UPPER motor neuron lesions result in \_\_\_\_, \_\_\_\_\_ and \_\_\_\_\_\_\_\_</p>
<p>UPPER motor neuron lesions result in {HES} 1. SPASTIC PARALYSIS 2. Exaggerated Reflexes 3. Hemiplegia (1 sided paralysis)</p>
<p>A: lower motor neuron lesions result in \_\_\_\_, \_\_\_\_\_ and \_\_\_\_\_\_\_\_</p>
<p>B: Which cells are the LOWER motor neurons?</p>
<p>lower motor neuron lesions result in {fOf] 1. flaccid PARALYSIS 2.hypOreflexivity 3. fasciculations</p>
<p>B: [ANT Horn Cells] and their axons</p>
Gluteus MAX has a ___[Many/few] Large motor units because _________
vs.
Flexor Digi Profundus which has ___[Many/few] Large motor units because_____
Gluteus MAX has a few Large motor units because its actions ARE NOT precise
vs.
Flexor Digi Profundus which has MANY Large motor units
<p>[ALS & Polio] causes the degeneration of \_\_\_\_ and \_\_\_\_. These affect \_\_\_\_[UPPER/lower] motor neuron activity MORE! What type of sx would this cause? [3]</p>
<p>ALS/Polio causes the degeneration of [ANT Horn cells] and [Pyramidal Betz cells]. This affects the lower motor neuron activity MORE = fOf 1. flaccid paralysis 2. hypOreflexivity 3. fasciculations</p>
<p>A: In what 2 instances do you see a POSITIVE Babinski Sign</p>
<p>B: What does a POSITIVE Babinski Sign look like? [2]</p>
<p>POSITIVE Babinski Sign</p>
<p>1. [UPPER Motor Neuron] damage --> {HES} sx</p>
<p>2. infants</p>
<p>B: Pt [Hallux DORSIflexes] & toes fan out</p>
<p>A: Why is the <strong>interpeduncular Fossa</strong> significant? Where is it located?</p>
<p>B: The [SUP cerebellar Peduncle] decusates in the [Caudal MIDBRAIN]</p>
<p>A: The interpeduncular Fossa is significant because [Oculomotor CN3] runs out of it. It is found in the MIDBRAIN between the 2 [Crus Cerebri Cerebral Peduncle}</p>
<p>B: The [SUP cerebellar Peduncle] decusates in the [Caudal MIDBRAIN]</p>
<p>1. Which 2 tracts cross in Medulla?</p>
<p>2. Sympathetics are found in the \_\_\_\_</p>
<p>3. Medial and Lateral motor nuclei are related to the \_\_\_\_ Tract</p>
<p>4. Which 2 tracts uses the [inferior Cerebellar peduncle] (ICP)?</p>
<p>5. DSCT uses \_\_\_ Nucleus before going to \_\_\_\_\_</p>
<p>6. \_\_\_, \_\_\_\_ and \_\_\_\_ tracts all cross in the Spinal Cord</p>
<p>7. Medial Lemniscus uses the \_\_\_\_ \_\_\_\_\_ pathway</p>
<p>8. Nucleus Proprius is related to the \_\_\_ \_\_\_\_ Tract</p>
<p>1. CST and DCP = cross in Medulla</p>
<p>2. Sympathetics are found in the [Lateral Horn/IML]</p>
<p>3. Medial and Lateral motor nuclei are related to the CORTICOSPINAL TRACT (CST)</p>
<p>4. DSCT & CCT use ICP<span> [<em>Remember: VSCT uses SCP</em>] </span></p>
<p>5. DSCT uses <strong>Clark's Nucleus</strong> before going to ICP</p>
<p>6. VSCT / [ANT CST]/ STT all cross in the Spinal Cord</p>
<p>7. Medial Lemniscus uses the [Dorsal Column Pathway]</p>
<p>8. Nucleus Proprius is related to the [Spinal Thalamic Tract]</p>
