Motor Pathways Flashcards
Give the 3 main groups of fibres.
Projection fibers. Association fibers. Commissural fibres.
What do projection fibres connect?
Connect a lobe to other parts of the brain.
What do association fibres do?
Connect regions within the same hemisphere.
What do commissural fibres do?
Connect 2 hemispheres.
What is the corpus callosum?
Thick nerve tract consisting of a flat bundle of commissural fibres.
Give the role of descending nerve pathways.
Voluntary movement. Sensory driven reflex responses.
Give 3 areas of the cortex.
Premotor cortex. Supplementary cortex. Primary motor cortex.
What is the function of the premotor cortex?
Plan movement.
What is the function of the supplementary cortex?
Strategize and achieve goal.
What is the function of the primary motor cortex?
Activate spinal motor neurones and initiate movement.
Give the 2 descending tracts of the primary motor cortex.
Corticospinal and corticobulbar.
What two things does the corticobulbar connect?
Connects cortex and medulla oblongata.
What cells make up the corticospinal tract?
Large Betz cells.
Corticostriate (to basal ganglia) and corticothalamic (thalamus) go through what?
Corona radiata.
Where is the most common site for strokes?
Internal capsule.
What does the mid-brain coordinate?
Voluntary eye and head movements.
What happens to the corticospinal tract at the medulla?
They crossover and bundle together.
What are the two tracts of the pyramidal tracts?
Corticospinal and corticobulbar.
Corticobulbar tract connects impulses between what?
Brain to the cranial nerves.
Corticospinal tract connects impulses between what?
Brain to the spinal cord.
What nerves control the muscles of the face and neck and are involved in facial expression, mastication, swallowing, and other functions.
Cranial nerves.
What tract is involved with voluntary movement.
Corticospinal tract.
Why are they named pyramid tracts?
Because they pass through the pyramids of the medulla oblongata.
The tract going from the cortex to the pons is known as the…
Corticopontine tract.
What is the function of lateral corticospinal tracts?
Skilled movements hands and feet.
What is the function of anterior corticospinal tracts?
Innervate arms and neck
Name 2 of the 4 extrapyramidal tracts.
Vestibulospinal, tectospinal, reticulospinal, rubospinal.
What is the function of the vestibulospinal tract.
Control balance and posture.
The extrapyramidal system centers on the modulation and regulation (indirect control) of which cells.
Anterior (ventral) horn
What is the function of the tectospinal tract?
Head movements in response to visual/auditory signals.
What is the function of the reticulospinal tract?
Mediates motor function, mediates autonomic function and pain pathway.
What is the function of the rubrospinal tract?
Fine control hand movements. Locomotion.
What is the difference between the pyramidal and extrapyramidal tracts?
Pyramidal tracts originate in the cerebral cortex, carrying motor fibres to the spinal cord and brain stem but extrapyramidal tracts originate in the brain stem, carrying motor fibres to the spinal cord.
Pyramidal tracts are are responsible for the voluntary control of the musculature of the body and face but, extrapyramidal tracts are responsible for the involuntary and automatic control of all musculature, such as muscle tone, balance, posture and locomotion
