Pnb 2xb3 somatosensory - Study guides, Class notes & Summaries

DCML - 1) mechanosensory receptors send info to fibers in gracile & cuneate pathways 2) fibers travel to caudal medulla, synapse at dorsal column nucleus (and switch sides) 3) exit DCN as arcuate fibers, cross the midline to form medial lemniscus carries through pons, midbrain, brainstem 4) synapse at thalamus (VPL) 5) internal capsule takes axons to post-central gyrus/S1, some to S2. Meissener - - rapidly adapting -40% of mechanosensory innervation in hand - skin motion, indentation, lo...

RAPID-adapting mechanoreceptors - ️️Meissner and Pacinian (dynamic phase QUICKLY becomes static phase) dorsal root ganglion (DRG) - ️️(part of the PNS) cluster of cell bodies in the dorsal root of a spinal nerve (when the action potential reaches the DRG, it splits into 2 - one travels toward the cell body and the other continues down the axon) dorsal horn - ️️the POSTERIOR column of grey matter in the spinal cord (shape differs depending on spinal segment) - contains SENSORY n...

Merkell cells - ~~> - slowly adapting - 25% of mechanosensory afferents in hand - highest spatial resolution - edges, points, corners, curvature - static indentation ** Meissener - ~~> - rapidly adapting -40% of mechanosensory innervation in hand - skin motion, indentation, low frequency vibrations for textured objects*** - more than 4x more sensitive than Merkell to skin deformation, but larger receptive fields so less spatial resolution - ie. tea set plate etchin...

dermatome - ~~> the area of skin supplied by the sensory axons of a single spinal nerve dorsal horn - ~~> the POSTERIOR column of grey matter in the spinal cord (shape differs depending on spinal segment) - contains SENSORY neuron cell bodies ventral horn - ~~> the ANTERIOR column of grey matter in the spinal cord (shape differs depending on spinal segment) - contains MOTOR neuron cell bodies 3 types of primary somatosensory afferent axons - ~~> 1) Aβ 2) Aδ 3...

PNB 2XB3 Lecture 4: Somatosensory System Exam Study Guide with Complete Solutions dermatome - Answer-the area of skin supplied by the sensory axons of a single spinal nerve dorsal horn - Answer-the POSTERIOR column of grey matter in the spinal cord (shape differs depending on spinal segment) - contains SENSORY neuron cell bodies ventral horn - Answer-the ANTERIOR column of grey matter in the spinal cord (shape differs depending on spinal segment) - contains MOTOR neuron cell bodies 3 ty...

PNB 2XB3 - Midterm 2: Somatosensory Exam Study Guide with Complete Solutions Merkell cells - Answer-- slowly adapting - 25% of mechanosensory afferents in hand - highest spatial resolution - edges, points, corners, curvature - static indentation ** Meissener - Answer-- rapidly adapting -40% of mechanosensory innervation in hand - skin motion, indentation, low frequency vibrations for textured objects*** - more than 4x more sensitive than Merkell to skin deformation, but larger recepti...

PNB 2XB3 Neuroscience Midterm Review Study Guide with Complete Solutions Central Nervous System (CNS) - Answer-all parts of the nervous system within bone (spinal cord, brainstem, thalamus, cortex, etc) Peripheral Nervous System (PNS) - Answer-all parts not within bone (spinal nerves, cranial nerves) Cranial nerve - Answer-One of twelve pairs of nerves arising from the brainstem that carry sensory information towards the central nervous system Spinal nerve - Answer-A nerve which carries...