01:146:245 Lecture Notes - Lecture 13: Dorsal Root Ganglion, Cuneate Nucleus, Medial Lemniscus

• School: Rutgers University
• Department: Cell Biology and Neuroscience
• Course: 01:146:245
• Professor: Professor Wilhelms

Document Summary

~the action potentials made by tactile stimuli are transmitted to spinal cord by afferent axons in peripheral nerves. ~the cell bodies for these axons are in dorsal root (sensory) ganglia. Remember dorsal root ganglia are associated with each spinal nerve. ~ganglion cell has a peripheral axon and central axon. ~the ganglion cells have long peripheral axons that have the receptor specializations at the end. ~central axon is shorter, goes to dorsolateral part of spinal cord via dorsal roots, for each spinal segment. ~mechanoreceptors are low-threshold, large and myelinated axon associated with large ganglion cells. ~nociceptors and thermoceptors are high-threshold associated with small ganglion cells. ~there are distinct somatic sensory pathways in cns for mechano vs. noci/thermos. ~dorsal column-medial lemniscus pathway (dcml) carries info from mechano and proprioceptors. ~spinothalamic pathway carries info from noci/thermo, for pain and temperature. ~the first order axons bifurcate into ascending and descending branches.