SC 3

medicoblasto's version from 2016-09-16 13:40

Pyramidal and extrapyramidal Tracts

Question Answer
Voluntary, discrete, skilled motor movements. Corticospinal
Facilitation of voluntary and reflex movements via modulation of motor neurons in anterior horn.Reticulospinal
Reflex postural movements in response to visual stimuli (visuo-postural reflex).Tectospinal
Inhibits extensor muscles, facilitates flexor muscles.Rubrospinal
Facilitates extensor, inhibits flexor muscles. Also involved in postural control and balance.Vestibulospinal
muscle activity.Olivospinal
Descends through brain ipsilaterally, then crosses and descends contralaterally in cordLateral Corticospinal
Descends ipsilaterally all the way to the cord, then innervates bilaterally.Anterior Corticospinal

UMN and LMN Symptoms

Question Answer
Paresis (hemiparesis)CST lesion
Babinski sign ‘present’CST lesion
Hoffman’s sign presentCST lesion
Abdominal reflex absentCST lesion
Cremasteric reflex absentCST lesion
Spasticity, which is hyperreflexia of DTR’s, clonus, and increased muscle tone (rigidity).CST lesion