Course Hero Logo

Innervates pelvic organs lower limbs meninges

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 6 - 8 out of 9 pages.

innervates pelvic organs, lower limbsMeningesSeparates soft tissue ofCNS from the craniumand vertebral canalThree fibrous membranesthat enclose the brainand spinal cordConsist of (superficial to deep):1.Dura mater– dura = tough2.Arachnoid mater3.Pia materDural sheath surrounds spinal cord and is separated from vertebrae by theepidural spaceMeningesArachnoid Materadheres to the duraseparated from pia by thesubarachnoid space:filled with cerebrospinal fluidlumbar puncture (spinal tap) takessamples of CSF at L3/L4 or L4/L5 (norisk of spinal cord injury)Pia Materdelicate membrane that followsthe contours of the spinal cordcontinues inferiorly as the fibrousterminal filumthat fuses with thedura to form the coccygealligamentLumbar punctureEpiduralSpina bifidaCongenital defectOne or more vertebrae fail to form acomplete vertebral arch for enclosure ofthe spinal cord1 baby in 1,000Common in lumbosacral regionFolic acid (leafy greens) reduces incidenceNote ‐ start 3 months before conception, asdefect occurs in the first 4 weeksCross‐sectional anatomy of the spinal cordGray matterCentral areaNeuron cell bodies withlittle myelin (site ofsynaptic integration)White matterSurrounds gray matterAbundantly myelinatedaxons (carry signals inthe CNS)Note: grey matter incerebral cortex of brain (nota medullary position)
2017‐10‐047Gray matter – central corePosterior (dorsal) hornsPosterior root carries sensory nervefibresAnterior (ventral) hornsAnterior (ventral) root of spinal nervecarries only motor fibresGray commissureconnects rightand left sidesCentral canal lined with ependymalcells and filled with CSFLateral hornVisible from T2 through L1Contains neurons of the sympatheticnervous systemReflex exampleWhite matterSurrounds gray matterBundles of axons up and down thecord providing communicationbetween different levels of CNSColumns (funiculi):1. Posterior (dorsal)2. Lateral3. Anterior (ventral)Each column/ funiculus consists ofsubdivisions = Tracts or fasciculiPosteriorLateralAnteriorSpinal cord tract organizationFibres within a given tract have similar origin, destination, and functionAscending tracts – carry sensory information upDescending tracts – carry motor information downTract decussation‐ crossing of the midline that occurs in many tracts so that brainsenses and controls contralateral side of body (i.e., tracts go left to right, orvice versa)Different points of decussation for different tracts (spinal cord, medulla, midbrain)Ascending tractsSensory signals travel across three neuronsfrom origin (receptors) to destinations in thesensory areas of the brainFirst‐order neuronsDetects stimulus and transmits signal to spinal cord orbrainstemSecond‐order neuronsContinues to the thalamus at the upper end of thebrainstemThird‐order neuronsCarries the signal the rest of the way to the sensoryregion of the cerebral cortexCuneate fasciculus

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 9 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Winter
Professor
Staff
Tags
pia mater

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