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Sensory pathways Dr. Gallatz Katalin

Sensory pathways Dr. Gallatz Katalin. SENSORY PATHWAYS. Spinothalamic system is for the pain temperature and light touch protopathic sensibility. Medial lemniscus is for fine and discrimitive touch , vibration and propriocepcion epicritic sensibility.

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Sensory pathways Dr. Gallatz Katalin

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  1. Sensory pathwaysDr. Gallatz Katalin

  2. SENSORY PATHWAYS Spinothalamicsystem isforthepaintemperature and lighttouchprotopathicsensibility Mediallemniscus is forfine and discrimitivetouch, vibrationandpropriocepcion epicriticsensibility In contrast of the spinothalamic system, in which fibers cross at the spinal level, the fibers that costitute the medial lemniscus system ascend ipsilaterally in the dorsal funiculus and cross in the caudal medulla

  3. PROTOPATHIC SENSIBILITY: TEMPERATURE, TOUCH, PAIN ANTEROLATERAL SYSTEM – spinothalamictract EPICRITIC SENSIBILITY: FINE AND DISCRIMINITIVE TOUCH DORSAL COLUMNSYSTEM– mediallemniscus

  4. PRIMARY AFFERENTS

  5. Receptors:of the touch - Meissner corpuscles of vibration – Paccinian corpuscles of proprioception – muscle spindles, tendon spindles, Golgi tendon organs nerve endings in and near to thecapsules and ligaments of the joints EPICRITIC SENSYBILITY

  6. MEDIAL LEMNISCUS – EPICRITIC SENSIBILITY FINE AND DISCRIMINITIVE TOUCH I. neuron: spinal ggl/trigeminal ggl gracile és cuneate fascicle II. neuron: gracile and cuneate nucleus internal arcuate fibers X MEDIAL LEMNISCUS III. neuron: VPL (contralateral) SOMATOSENSORY CORTEX

  7. MEDIAL LEMNISCUS – EPICRITIC SENSIBILITY 1. neuron: spinal ( dorsal root) ganglion the central processes of the ganglion cells enter the spinal cord through the spinal root and ascend in the gracile and cuneate fascicles to the caudal medulla 2. neuron: gracile and cuneate nucleus the axons of these neurons - the internal arcuate fibers cross in the midline - lemniscal deccusation, and ascend as medial lemniscus to the thalamus 3. neuron: ventral posterolateral (VPL) nucleus of the thalamus the axons of these neurons ascend through the internal capsule to the postcentral gyrus - primary somato- sensory cortex

  8. MEDIAL LEMNISCUS – EPICRITIC SENSIBILITY

  9. SOMATOTOPY IN THE SPINAL CORD

  10. SPINOTHALAMIC TRACT – PROTOPATHIC SENSYBILITY - pain, touch, temperature • receptorsintheskin: mechano,- termo, and nociceptors 1. neuron: spinalganglionortrigeminalganglion 2. neuron: inthedorsalhorn of thespinalcord orinthespinaltrigeminalnucleus. (inpainsensationalsothe 3. neuron) 3. neuron: thalamus VPL orVPM somatosensycortex – postcentralgyrus

  11. SPINOTHALAMIC TRACT Dr. Kozsurek Márk anyagából

  12. MEDIAL LEMNISCUS epicritic sensibility 2. neuron and crossing in the medulla SPINOTHALAMIC TRACT protopathic sensibility 2. neuron and crossing in the spinal cord

  13. SZOMATOSENSORY PATHWAYS CONNECTING WITH THE PAIN SENSATION termination ------------------ thalamus (VPL), VPM primary and secondary sensory cortex (SI, SII) pathways --------------------------- Spinothalamic tract Ventral trigeminothalamic tract (ventral trigeminal lemniscus) functional activity ------------------------ localization and discrimination Spinoreticulothalamic tractreticular formaton (RF) Pain-feelingintralaminar nuclei of th. It has function in emotional, limbic cortical areas affective and behavioural answers for pain sensation

  14. NUCLEI OF THE TRIGEMINAL NERVE MESENCEPHALIC NUCLEUS PRINCIPAL SENSORY NUCLEUS SPINAL TRIGEMINAL NUCLEUS

  15. TRIGEMINAL SENSORY PATHWAYS DORSAL TRIGEMINAL LEMNISCUS TRIGEMINAL LEMNISCUS

  16. VENTRAL TRIGEMINOTHALAMIC TRACT. TRIGEMINAL LEMNISCUS TRIGEMINAL GANGLION SPINAL TRIGEMINAL TRACT SPINAL TRIGEMINAL NUCL. X Contralateral VPM POSTCENTRAL GYRUS

  17. TRIGEMINAL SENSORY PATHWAYS

  18. TRIGEMINAL SENSORY PATHWAYS DORSAL TRIGEMINOTHALAMICTRACT DORSAL TRIGEMINAL LEMNISCUS epicritic sensibility trigeminal ganglion principal sensory nucleus of V. VPM postcentral gyrus

  19. SOMATOTOPY

  20. SOMATOSENSORY CORTEX THALAMUS

  21. PAIN - The pain is an unpleasant sensation, but it is life-important in our connection with the outside-world. - The brain can recognize and localize the pain, and activates a lot of mechanizms. - The organism gives different and complex answersfor the pain. In the pain sensation participate: - sensory receptors, - sensory fibers, - ascending pathway- neurons. Receptors - nociceptors

  22. Nociceptors • areactivatedbyanyprocessthateithercausesdamageor has thecapacitytocausedamageifcontinuedorintensified, - most nociceptorsrespondto a variety of noxiousstimuli: - extreme hotorcoldtemperatures, - intensemechanicalmanipulations (pinching, pinpricks, cutting), - increasedtissueacidity, and othercauses of injury, - a variety of chemicalagentsreleasedfromcellsthat aredamagedorrespondingto a foreign body suchas an infectiousagent (forexample, a bacterium)

  23. Melzack és Wall gate control theory • The stimulation of thick (touch, • pressure, vibration) sensoryfibers • excite, • whilethestimulation of thethin(pain) sensoryfibersinhibittheactivity of inhibitoryinterneuronsregulatingtheactivityoffunicularneuronsofascendingpathways. Inhibitory neuron Projection neuron inhibition of the inhibitory neurons stimulation of thin fibers Gate opens toward the ascending pathway-neurons

  24. The answers for the pain-producing stimuli - protective reflex – spinal cord, brainstem - vegetative reflex – spinal cord, brainstem - a recognition and localization of the pain - primer és secunder sensory cortex - emotional reactions - limbic cortex - hormonal changes - hypothalamus

  25. PAIN-CONDUCTING PATHWAYS terminals thalamus (VPL) - sensory cortex midline thalamic nuclei - limbic cortex pathways spinothalamic tract trigeminal lemniscus spinoreticulothalamic tract trigemino-reticulothalamic tract activity localization and discrimination of the pain pain motivation, affective and behavioral responses

  26. PAIN SENSATION –spinoreticulo- thalamic tract Pain-feeling. It has function in emotional, affective and behavioural answers for pain sensation. - receptors are in the skin - nociceptors - I. neuron: spinal ganglion or trigeminal ganglion - II-III. neuron: spinal cord or spinal trigeminal nucleus • further neurons : reticular formation, thalamus CM and intralaminar nuclei • frontal cortex • limbic cortical areas: cingular, insular cortex

  27. Thank you for your attention!

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