Ustnotesgroup2010neuropractical Compressed)

USTNotesGroup2010 Transcribed from Dra. Bautista Lecture of Section B Rm 5 Notes from A. Abad and Maueewowee Vertebral Column

Thoracic Vertebrae • Body is Heart Shaped

Cervical Vertebrae

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Bifid spine, Transverse Foramen @ transverse process which allows passage of vertebral artery Slide view a. Relatively small dorsal and ventral horn b. Thick dorsal, lateral, and ventral funiculus c. White matter is thicker compared to the gray d. No lateral horn

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Spine Long and oriented downwards, because of the orientation of the spine it’s hard to do a spinal tab.

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Slide view a. Intermediolateral Cell Column is found here T1-L2 b. Sympathetic Preganglionic Efferents c. Will appear as the LATERAL HORN (only found in thoracic) d. Ventral Horn and Dorsal Horn are thin e. White Matter is Thick

Vertebral Column • Body is joined by another body through the Intervertebral Disc, if no glue in between them your spine will be moving around all the time. Why you can have herniated disc • Opening found when one it’s the Vertebral Foramen

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If you join two or more vertebral foramen it becomes a Vertebral Canal, when formed will allow passage of spinal cord, covering the meninges, CSF, and the nerve roots

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Two nerve roots dorsal and ventral will unite at the vertebral foramen to form Spinal Nerve, so before foramen you have only nerve roots.

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Boundary of the foramen, anteriorly you have the body posterior laterally is the neural arch. Neural Arch made of the Pedicle, Lamina, and Spine

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spinal. Needle is stuck and placed into the subarachnoid space. In this you want the patient to flex to open up the interlaminar space so you can puncture and pass through the supraspinous, interspinous, and Ligamentum Flavum. So you can go directly into the vertebral canal. Remember spinal tap is down after L1-L2. So you do it lower, so god is good since he made it easier to do the lumbar tap.

Sacrum • Obvious of course • Slide a. very thin film of white matter, surrounding the very wide grey Know the parts of the vertebrae and distinguish one from another. Lumbar • Kidney shape • Spine is hatchet (square) shape and orientation is horizontal • Slide View a. Thicker gray, Thinner white matter b. Thin ventral funiculus & Thin lateral funiculus c. Wide Ventral Horn; Thin Dorsal Horn Support • Body joined via Intervertebral Disc

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Supraspinous Ligament connects the tips of the spine. Puts together all the spine from the cervical down Interspinous Ligament connects in between body of the spine to the next. Ligamentum Flavum- Join the lamina together, joining one lamina to the one lamina below. Covers a space so that t If flex, it joins the two lamina and covers a space called Interlaminar Space. Those that have Appendectomy, Caesarian, and the anesthesia are

Comparison amongst Vertebral slides

 Gray Matter-contains nerve cell bodies (nuclei), divided into 3 parts • Dorsal Horn o Somatosensory  Rexed Lamina 1-6

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Dorsal Nucleus of Clark (which actually belongs to Lamina 7, and conveys UNCONSCIOUS proprioception thru the Dorsal Spinocerebellar Tract)  Dorsal Spinocerebellar Tract conveys unconscious proprioception from Rex Lamina 7 (Dorsal Nucleus of Clark) to Cerebellum Intermediate Zone

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Autonomic (Visceral Motor and Visceral Sensory); T1-L2

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IMM (Intermediomedial) Cell Column is found in the intermediate zone and only T1-L2

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IML (Intermediolateral) Cell Column at T1-L2, forms a prominent bulge which forms the Lateral Horn at the thoracic cord segment Sacral Autonomic Nuclei Rexed Lamina 7 Rexed Lamina 10 surrounds the central canal So remaining nuclei of Rexed Lamina 7 and Rexed Lamina 10 are autonomic in function

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Lateral Horn (in orange) which is the origin of your sympathetic preganglionic efferent nerve fibers. IML cell column will exit through the ventral root and pass through the spinal nerve, leave the spinal nerve as white ramus. Can go to the paravertebral ganglia can go up or down; or bypass it to prevertebral as your splenic nerve.

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Fibers pass through the grey rami, are C fiber, slowest conductive velocity. They are unmyelinated White Matter- contains the numerous fiber tracts; they surround the grey and are made up of ascending and descending fiber tracts  can be divided into 3 groups 1. Ventral Funiculus- b/w ventral median fissure and ventrolateral sulci 2. Dorsal Column- b/w dorsal median sulcus and dorsolateral sulcus 3. Lateral Funiculus- b/w dorsolateral sulci and ventrolateral sulci  Fiber tracts- ascend and descend  Ascending-usually sensory*  Descending-usually motor8* *not always

Fiber tracts are ascending and descend. Names are named after origin and termination.  Spinothalamic is spinal cord and thalamus  Corticospinal is cerebral cortex and spinal cord

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Ascending fiber tract have the dorsal root ganglion giving rise to a central process which is one whole neuron (body, peripheral process, central process, and there is no synapse). Synapse only when it joins or ends in another nucleus so it’s Pseudounipolar. Nucleus 2 is the nucleus inside.

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Once enters and goes through the dorsal horn example for pain and temperature will go up opposite side as the lateral spinothalamic tract in lateral funiculus. Nerve fibers are A delta and C.

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Crude touch will cross and ascend in ventral nucleus as ventral funiculus as ventral spinothalamic tract.

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Sympathetic Preganglionic Efferent are class B Fibers, shortest internodes; thinnest myelin sheath; motor function, pass through the white rami Ventral Horn  Somatomotor  Rexed Lamina 8,9  Motor Neurons A (alpha/gamma): primarily located in lamina 9

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Medial Motor Neuron Group *

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Lateral Motor Neuron Group*

*Proximal-Distal Rule 1. Medial Motor Neurons- will supply the medially proximally located muscles of the body which will be the neck, trunk, and girdle muscles (shoulder, pelvic) 2. Lateral Motor Neurons- will supply muscles that are laterally distally located, both upper and lower extremities (hands, feet) - Proprioception is position sense. - Unconscious will not reach consciousness and will only reach the cerebellum.

Have the lateral horn in the thoracic cord segment. If you find lateral horn, look at the size of the dorsal and ventral gray is thinner will tell you it’s thoracic Look at the lateral horn compared to cervical, lumbar, and sacral. The have thicker dorsal and ventral gray. And no lateral horn If want to orientate yourself to see which is dorsal and which is ventral, look at the dorsal median fissure.

Additional Info • Spinal Cord anything that is spinal cord in origin will serve the neck, trunk, and limbs. • Head is cranial nerve, facial muscle, open eyes, swallow

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So if you decapitate anything head neck, trunk, and limb are spinal cord. It will not supply the face. Pain and temperature convey by lateral spinothalamic tract will come from noiceptors or neck, trunk, and limbs Crude Touch is also for neck, trunk, and limbs. Which are cutaneous mechanoreceptors.

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In dorsal column or dorsal furnuculus there is another ascending fiber tract which is for conscious proprioception, crude touch, and vibration sense Dorsal Nucleus of Clarke, dorsal spinocerebellar unconscious proprioception for trunks and limb

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Dorsal Column

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Conscious proprioception goes up the dorsal column which goes up to the thalamus and cerebral cortex for you to perceive consciously. If you convey conscious proprioception from the trunks and limbs, notice the fibers that enter first enter from below. So the fibers from the lower limb/trunk entering via dorsal root and ascending up. Passing through the dorsal folliculus.

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When you reach cervical segment, you have fibers from upper trunk and limb entering the elevator and occupy the more peripheral portion since they enter last.

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At cervical segment, you will have division of dorsal folliculus to Fasciculus Gracilis and Fasciculus Cuneatus

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Fasciculus Gracilis*-medially located, Conscious proprioception from lower trunk and extremities

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associated with CONSCIOUS proprioception, fine touch, & vibration sense A-alpha fibers division of Dorsal Column o Fasciculus Gracilis  medially located

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Corticospinal from cortex and end in spinal cord, and ends in a motor nucleus in the cord found in the ventral grey horn. Which are 8 and 9. 9 is location of cell body of motor neuron which exit which gives rise to ventral root and exit as A alpha and A gamma efferents.

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9 is divided into two groups that you have lateral group and medial group. So motor neurons aren’t distributed randomly which are proximal/distal rule and flexor/extensor rule.

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Motor neuron lamina 9 is divided in lateral group and medial group. Medial group supply muscle for neck trunk and limbs. Motor neurons medial will give rise to A alpha and A gamma to supply neck, trunk, and proximal limbs (shoulder, girdle and pelvic girdle.

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Neurons in lateral group will go out and form A alpha and A gamma efferent to supply the distal limb. (look at proximal distal rule above)

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Conscious proprioception from lower trunk and extremities Fasciculus Cuneatus  laterally located

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Conscious proprioception from upper trunk and extremities * The dorsal intermediate sulcus is found between the fasciculus gracilis and cuneatus only at the cervical and mid-thoracic level. At the lumbar level, there are no fibers from the upper trunk/extremities…only fibers from the lower extremities Ventral and Lateral Funiculi o Ventral Funiculus-look for ventral median fissure o Lateral Funiculus-can be seen without looking under a microscope o Both ascending and descending tracts o Ascending –spinal cord to the thalamus to the cortex 1. Lateral Spinothalamic Tract- fibers for pain and temperature a. Receptor – Free Nerve Endings b. Nociceptors/ Thermoreceptors i. peripheral nerve fibers Adelta & C enter the spinal cord as the dorsal root, which will then synapse at the sensory nucleus in the

Descending – Corticospinal Tract for movement; from the cortex to the cord 1. Ventral Corticospinal Tract a. Ventral Funiculus b. Trunk muscles 2. Lateral Corticospinal Tract a. Lateral Funiculus b. Lower and upper extremities

Correlations • Descending pathway corticortical spinal track. Only two lateral in lateral funiculus and ventral at ventral funiculus. • Dorsal is purely sensory and ascending from trunk and limbs • Ventral and Lateral funiculus is both ascending and descending.

Fasciculus Cuneatus*- laterally located, Conscious proprioception from upper trunk and extremities Ascending pathway can be found more at cervical

Dorsal Column • purely ascending fiber tracts (sensory)

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dorsal horn that will ascend as the lateral spinothalamic tract in the lateral funiculus for pain Ventral Spinothalamic Tract- fibers for crude touch a. Receptor- Mechanoreceptors i. Peripheral nerve fibers Abeta will synapse at the sensory nucleus will ascend as the ventral spinothalamic tract in the ventral funiculus.

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Premise 1 Lateral motor neuron supply distal limb Premise 2 Lateral corticospinal tract terminates in lateral motor neurons. So Lateral corticospinal tract will supply distal limbs Ventral corticospinal tract terminate in the medial motor neuron and is bilateral. The ventral corticospinal tract will supply the neck, trunk and proximal limbs. Ventral funiculus fibers pass through this convey Crude Touch because of the Ventral Spinothalamic Tract. It also supplies proximal limbs because of Ventral Corticospinal tract. Lateral funiculus fibers pass through this convey pain because of Lateral Spinothalamic Tract. It also supply the distal limb because of Lateral Corticospinal Tract Doral column convey fine touch

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Know Thoracic cord because has Lateral horn and very thin ventral horn and dorsal grey.

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Why thin because cervical and lumbosacral for the limb, while Thoracic for the trunk why small.

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More Ascending tract and descending tracts cervical, if you look at ratio of white to grey is thicker why there is more white matter. Versus the lumber where the grey is thicker than the white. Least number of descending at lumbar While at the sacral has a very thin film of white matter which is surrounding the very wide grey.

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