Lernmaterialien für Chapter 11 - Motor System an der Radboud University

main efferent pathways from the motor cortex to the brainstem to the spinal cord

-> tracts that control limbs and digits cross from one hemisphere to the opposite side of the spinal cord (lateral corticospinal tract)

-> parts that control trunk movements do not cross (anterior (or ventral) corticospinal tract)

Layer IV: afferent -> thicker in the sensory cortex, thinner in the motor cortex

Layer V: efferent -> thicker in the motor cortex, thinner in the sensory cortex

Prefrontal cortex: plans movements

Premotor cortex: organizes movement sequences (e.g. coordination of two hands)

Motor cortex: produces specific movements (e.g. gripping, other skilled movements)

controlled by the brainstem

-> innate and organised by brainstem neurons 

(experiments by Hess -> cats with electrodes in their brain)

producing complex patterns of adaptive behaviour is an important brainstem function

in the spinal cord,

anterior tracts are motor and

posterior tracts are sensory

brainstem damage mostly acquired before or shortly after birth 

 -> voluntary movements become difficult, while many other aspects of conscious behaviour remain intact

paralysis and loss of sensation in the arms and legs 

(everything below the cut)

paralysis and loss of sensation in the legs and lower body 

(both sides)

neural spatial representation of the body or areas of the sensory world perceived by a sensory organ

-> homunculus for somatosensory and motor areas