Lemniscal system
From WikiLectures
The Leminiscal system, also known as the Dorsal Column Tract, is important for conveying sensory information from the peripheral and internal structures to the brain
Pathway[edit | edit source]
- First order neuron - the tract starts at the dorsal root ganglion cell (pseudo-unipolar cells) with its dendrites in the periphery; axons enter the posterior funiculus and ascend in the posterior column nucleus (spinobulbar tract)
- Second order neuron - nerve fibres reach the gracilis and cuneate nucleus in the lower medulla oblongata, where its axons project to the thalamus (bulbothalamic tract); fibres of the bulbothalamic tract are internal arcuate fibres, crossing the mid-line (decussation) as they ascend, forming the medial Leminiscal pathway
- Third order neuron - these neurons are located in the ventro-posterolateral (VPL) and posterior nucleus of the thalamus (pulvinar) with VPL neurons terminating in the primary somato-sensory cortex; fibres from the pulvinar of thalamus terminates in the secondary somato-sensory and association cortex
Function[edit | edit source]
- Form recognition
- Proprioceptive sensation
- Tactile discrimination
- Vibration sensation
Links[edit | edit source]
Bibliography[edit | edit source]
SNELL, Richard S. Clinical Anatomy by Regions. 8th Edition edition. 2004. ISBN 978-0-7817-6404-9.
