1 / 29

Dr. Altdorfer: Microscopy of the spinal cord, proprioceptive and nociceptive reflexes

Dr. Altdorfer: Microscopy of the spinal cord, proprioceptive and nociceptive reflexes. Microscopy of the spinal cord. Dorsal horn: I-VI. Intermediate zone: VII., X. Ventral horn: VII-VIII-IX. Rexed I. Rexed II. III-IV. Rexed VII. Th9-L3. Rexed VII. Th1-L3. Rexed IX.

yasir-simon
Download Presentation

Dr. Altdorfer: Microscopy of the spinal cord, proprioceptive and nociceptive reflexes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Dr. Altdorfer: Microscopy of the spinal cord, proprioceptive and nociceptive reflexes

  2. Microscopy of the spinal cord Dorsal horn: I-VI. Intermediate zone: VII., X. Ventral horn: VII-VIII-IX.

  3. Rexed I. Rexed II. III-IV. Rexed VII. Th9-L3 Rexed VII. Th1-L3 Rexed IX.

  4. Spinal reflexes(reflex: stimulus  response) • Stretch reflex (or monosynaptic, proprioceptive, myotatic) • Withdrawal reflex (or polisynaptic, nociceptive, flexor…) • Autonomous reflex (or vegetative) • Receptor • Sensory neuron • (Interneuron) • Effector neuron • Effector organ

  5. Spinal reflexes • Stretch reflex (or monosynaptic, proprioceptive, myotatic) • Withdrawal reflex (or polisynaptic, nociceptive) • Autonomous reflex (or vegetative) • Receptor • Sensory neuron • (Interneuron) • Effector neuron • Effector organ

  6. Proprioceptive reflex

  7. Proprioceptive reflex

  8. Proprioceptive reflex

  9. Proprioceptive reflex • Receptor: muscle spindle • Sensory neuron: in DRG - Aα /Ia/ fibres • (Interneuron) no! • Effector neuron: in vental horn, Aα motoneuron • Effector organ: motor end plate (Ach) Antigravitation muscles – to set the tone / posture / body position Receptor and effector in the same striated muscle!

  10. Proprioceptive reflexes Inhibitory interneuron

  11. Receptor: muscle spindle

  12. Muscle spindle

  13. Muscle spindle • intrafusal muscle fibers (nuclear bag fibers, nuclear chain fibers) • motor neurons - gamma motor neurons (which activate intrafusal fibers) • sensory nerve fibers - annulospiral sensory nerve endings (Type Ia sensory fibers) - flower spray sensory nerve endings (Type II sensory fibers)

  14. Masseter reflex (jaw jerk reflex)

  15. Proprioceptive reflex

  16. Spinal reflexes(reflex: stimulus  response) • Stretch reflex (or monosynaptic, proprioceptive, myotatic) • Withdrawal reflex (or polisynaptic, nociceptive, flexor…) • Autonomous reflex (or vegetative) • Receptor • Sensory neuron • (Interneuron) • Effector neuron • Effector organ

  17. Withdrawal reflex Contraction of ipsilateral flexor muscles, inhibition of ipsilateral extensor (anatgonist) muscle motoneurons (reciprocal innervation) + On the other limb: …  crossed flexor-extensor reflex

  18. Withdrawal reflex Withdrawal reflex (or polisynaptic, nociceptive, flexor…) Protection from harmful stimuli (noxa) Receptor and effector in different tissues / organs!

  19. Withdrawal reflex • Receptor: free nerve endings (in skin, mucosa) - nociceptors • Sensory neuron: in DRG. Aδ , C fibres (thin myelin sheath or unmyelinated) • Interneuron: at least 1 in dorsal horn! • Effector neuron: in vental horn, Aα motoneuron • Effector organ: motor end plate (Ach) • E.g.: cremaster-reflex, cornea-reflex, pharyngeal (gag) reflex

  20. Withdrawal reflex • (or polisynaptic, nociceptive, flexor…) • Smaller diameter (Aδ, C) fibres  slower • Multisynaptic  longer latency

  21. Withdrawal reflex

  22. Withrawal reflex

  23. Withrawal reflex

  24. Stretch reflex • (or monosynaptic, proprioceptive, myotatic) • Setting the tone / posture / body position • Antigravitation muscles • Receptor and effector in the same striated muscle! • Withdrawal reflex • (or polisynaptic, nociceptive, flexor) • Protection from harmful stimuli (noxa) • Physiological flexor muscles • Receptor and effector in different tissues / organs!

More Related