N14 - descending pathways Flashcards
descending pathways are pathways for which type of control?
motor
controls fine distal flexors
it is the final common pathway to where?
alpha/gamma motor neurones
what does the spinal cord contain?
central pattern generators
where is the primary motor cortex located?
precentral gyrus
describe the pathway of the descending tracts
- primary motor cortex in precentral gyrus
- project down in internal capsule
- cerebral peduncles
- their axons are going to go in the midbrain, pons then into the medulla
- then down into the spinal cord and will then influence motor neurones in the spinal cord
where are the motor neurones located?
ventral or anterior horns
what are the motor neurones influenced by?
they are either influenced directly or through series of loops of interneurones which are essentially referred to as pattern generators
pattern genarators affect the motor neurones and its fibres, what is alpha and gamma affecting?
alpha is to do with force and gamma are within spindles
the corticospinal pathway is very important for?
fine motor control
are there any synapse within the corticospinal cord?
goes from cortex through midbrain and then reaches spinal cord all in one go with no synapses
where are descending tracts located?
lateral and ventral columns, corticospinal is mostly in the lateral column
where does the corticospinal tract crossover?
crosses over in lower medulla - decussation of pyramids
what can result as a interruption of the corticospinal tract at the internal capsule ?
- A stroke or cerebrovascular accident (CVA)
where will the effects most likely by of the CVA?
opposite side of the body
what is the function of reticulospinal?
repetitive movements, locomotion ie walking
