Lecture : Extrapyramidal tracts
Document Summary
The brainstem is where extrapyramidal pathways begin; they do not go through the pyramids. Each of these tracts carries motor fibres to the spinal cord, enabling muscles to contract unconsciously, automatically, or in response to external stimuli in order to regulate balance, movement, posture, and tone. Reticulospinal tracts - the reticulospinal circuits do not decussate. There are two components to the reticulospinal tracts: In response to alerting or activating stimuli that activate the reticular activating system, the medial reticulospinal tract, which originates in the pons, contributes to voluntary movements and muscular tone increases. The lateral reticulospinal tract, which emerges from the medulla, assists in reducing muscle tone and inhibiting voluntary movements. Two vestibulospinal routes via lmns regulate anti-gravity muscles: The ipsilateral postural and tone responses to the vestibular system are regulated by the medial vestibulospinal tract, which develops from the medial vestibular nucleus.
