Descending Tracts Flashcards
Where does a pyramidal tract originate?
Originate in the cerebral cortex
Carry motor fibres from the cortex to the spinal cord
What is the function of a pyramidal tract?
Carry motor fibres from the cortex to the spinal cord
Control voluntary movement of the muscles
Through what structure in the cortex do the corticospinal tracts move through?
Internal capsule
Where does the corticospinal tract split into the lateral and anterior tracts?
Caudal medulla
Describe the pathway of the lateral corticospinal tract
Decussate the midline in the medulla and descends in the spinal cord to terminate in the ventral horn
Describe the pathway of the anterior corticospinal tract
Remains ipsilateral as it descends and decussates and terminates in the ventral horn of the cervical and upper thoracic segmental levels
Where do the corticobulbar fibres terminate?
Motor nuclei of the cranial nerves
Describe the pathway of fibres in the corticobulbar tract
Lateral aspect of promary motor cortex
Internal capsule
Brainstem
Cranial nerve motor nuclei
What are the extrapyramidal tracts responsibe for?
Involuntary and voluntary control of musculature
Eg. muscle tone, balance, posture and locomotion
Describe the vestibulospinal tract pathway
Arise from the vestibular nuclei which recieve input from the organs of balance
Fibres remain ipsilateral
What does the vestibulospinal tract control?
Balance and posture
What does the medial reticulospinal tract control?
Voluntary movements
Increases muscle tone
What does the lateral reticulospinal tract control?
Inhibition of voluntary movements
Decreases muscle tone
Where do the rubrospinal tracts originate?
Red nucleus in the midbrain
What do the rubrospinal tracts control?
Fine movements of the hand
