BIO 11 Lecture Notes - Lecture 29: Spinothalamic Tract, Cuneate Nucleus, Skeletal Muscle
3 Sep 2020
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Document Summary
Sensory and motor pathways (tracts between cns/pns) Tracts are paired (bilateral, symmetrical arrangement within cord. Axons within each tract grouped by body region innervated. All tracts involve brain and spinal cord. Posterior columns funiculis (fg, fc) highly localized information fo skin and musculoskeletal. Dorsal column cuneate and gracile fasciculus. Axon from lower limb gracicle (fasciculis) Axon from upper limb cuneat fasciculus. Cuneate nucleus and gracile nucles they cross over to other side of brain stem (dessication) Romberg test: lesions below the decussation of its fibers loss of sensation on the same side of the body as the lesion. Above the decussation loss of sensation on the opposite side of the body than the lesion. First order from periphery to cns synapse, cell bodies within drg synapse in cord. Second order interneuron within cord or brain stem. Third order neuron located within thalamus communicates with suitable cortex area. Crosses at cord level synapses within dorsal horn.
