Descending Pathways Flashcards
Where do descending pathways originate?
The cerebral cortex and brain stem
What are the medial descending pathways concerned with?
Posture
Where do the medial descending pathways terminate?
Anteromedial portion of anterior grey horn
What are the lateral descending pathways concerned with?
Goal- directed movement
Where do the lateral descending pathways terminate?
Lateral part of anterior grey horn
Which pathway is part of extrapyramidal system?
The medial pathway
Which pathway is part of the pyramidal system?
The lateral pathway
Where do first order neurons in motor pathways arise?
Cell bodies in the cortex
Where do Giant Bentz cells arise?
Lower limb area of motor cortex (gives rise to largest portion of axons)
What do corticospinal fibres form in the medulla?
The pyramids
What are corticonuclear fibres?
Fibres given off by corticospinal fibres to cranial motor nuclei
What is the function of Renshaw cells?
Inactivate Ia inhibitory interneurons when cooperation between agonist and antagonist muscles are necessary
Where do fibres of corticospinal tract pass through?
Corona radiata and posterior limb of internal capsule
Where do fibres from corticonulear tract pass through?
The corona radiata and the genu of the internal capsule
What are the most medial fibres in the corticospinal tract?
The corticonuclear fibres