The ascending tracts

Chapter 15


The ascending tracts




Basic anatomy and function of the main ascending tracts


The ascending tracts emanate from various sensory receptors in the body and convey a detailed picture of the internal and external environment to the higher centres for decision-making purposes. Some may reach the cerebral cortex and hence be of conscious awareness, while others terminate subcortically and are therefore subconscious in nature.


The main ascending tracts include:




Basic structure of an ascending tract


As with the descending tracts, the ascending tracts have common anatomical features which generally consist of:



Sensory receptor




A 1st order neuron which is an afferent/sensory neuron in the peripheral nervous system. Its cell body is found in the dorsal root ganglion and it enters the spinal cord via the dorsal root. These neurons synapse on the 2nd order neuron


A 2nd order neuron which decussates and ascends the spinal cord in white matter to higher levels of the nervous system. These neurons synapse on the third order neuron


A 3rd order neuron

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Jun 4, 2016 | Posted by in NEUROLOGY | Comments Off on The ascending tracts

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