Course Hero Logo

Copy of NEUROII-SOMATOSENSORY-SYSTEM.pdf - NEUROSCIENCE 2...

Course Hero uses AI to attempt to automatically extract content from documents to surface to you and others so you can study better, e.g., in search results, to enrich docs, and more. This preview shows page 1 - 3 out of 5 pages.

1of5SANTOS, C., VILLANUEVA, C., VILLASERAN [SANTOS, M. A.]NEUROSCIENCE 2SOMATOSENSORY SYSTEMROSALES, M.D.1stSHIFT, August 14, 2017Topic OutlineI.Somatosensory SystemA. IntroductionB. Bell-Magendie LawC.Broadmann’s AreaD. Rexed LaminaII.Sensory Modalities: OverviewA. TouchB. Pain and Temperature1.Types of painC. ProprioceptionIII. Sensory Nerve FibersIV. Sensory Modalities: PathwaysA.Somatosensory Pathway (Generalities)B.Dorsal Column1.Fasciculus Gracilis2.Fasciculus CuneatusC.Anterolateral System1.Lateral Spinothalamic Tract2.Anterior Spinothalamic TractSome information were lifted from Haines and the SensoryPhysiology handout. Photos from Haines textbook (4thed),Haines atlas (6thed), and internet.SOMATOSENSORY SYSTEMSomato- bodySensory- consciousnessIntroductionCentral Sulcus of Rolando- separates the frontal and theparietal lobesFrontal- Motor (precentral gyrus)oPrimary motor cortex (BA 4)Parietal- Sensory (postcentral gyrus)oPrimary somatosensory cortex (BA 3-1-2)Homonculus- grotesque inverted figure (H-A-L)Figure 1. HomonculusPain in body area is not perceived unless it reaches itsspecific section in the homunculusSensory pathways- ascending pathwaysCerebellum- also involves ascending pathwaysAll sensory pathways areascending pathways but not allascending pathways are sensorypathways”Axon- where nerve impulse travelsoOnly myelinated segment of the neuron, making thepropagation faster =saltatory conductionoHigh density of Na+ channelsOpens Ca+ channels -> exocytosis -> Ach -> receptorSynapse- presynaptic + postsynaptic neuronoNo myelin, all grayBell-Magendie LawDorsalsensoryVentralmotoroThe line that demarcates each area is thecentral canaloThe impulse for pain is conveyed in the centripetaldirection towards the post-central gyrus via the spinalcord’s dorsal half, in the white matter where the axonsare locatedCentripetal: towards the nervous system1811-Charles BellFunction of the spinal cordAnesthetized ventral SC, then dorsal SC (rat is in comatose)oStimulated ventral (motor) = rat movedoStimulated dorsal (sensory) = no responseFirst to distinguish between motor and sensory nerves1822- Francois MagendieTwilight anesthesia is now available (rat is conscious)oStimulated ventral (motor) = rat movedoStimulated dorsal (sensory) = rat grimaced in painBroadmann’s Area1902- Korbinian BroadmannMapped out 52 areas in the cerebral cortexEach area has the same nerve cell bodiesRexed Lamina1952- Bror RexedRexed Lamina- 10 areas mapped out in the central gray ofthe spinal cordoLaminae I-VI: in the dorsal hornoLamina VII: in the intermediate zoneoLamina VIII: occupies much of the ventral hornoLamina IX: interspersed in and alongside VIIIoLamina X: area surrounding the central canal
Neuroscience 2: Somatosensory System2of5SANTOS, C., VILLANUEVA, C., VILLASERAN [SANTOS, M. A.]Lamina Ioaka posterior marginal nucleus or zoneLamina IIoaka substantia gelatinosaowhere pain impulses travel through, to be projected to the

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 5 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Fall
Professor
N/A
Tags

Newly uploaded documents

Show More

Newly uploaded documents

Show More

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture