All the Fucking Pathways

Question 1

Vestibulocerebellum

Answer 1

oldest functional division of the cerebellum, concerned with regulation of eye movements, balance, and equilibrium, components are the flocculonodular lobe, sensory input from the inner ear (vestibular labyrinth) and vestibular nuclei via the inferior cerebellar peduncles, output is inhibitory to the vestibular nuclei (medial and superior to coordinate eye movements, lateral to the axial muscles and limb extenders in order to maintain proper posture and balance) via the inferior cerebellar peduncle

Question 2

Vestibulospinal Tract

Answer 2

Origin: lateral vestibular nucleus, Side: Ipsilateral through brainstem and ventromedial spinal cord, Influence: alpha motor neuron pools, General Facts: provides a rapid, direct connection for information about head movements to the spinal motor system, maintains posture and balance, (the descending portion of the MLF originates in the medial vestibular nucleus)

Question 3

Reticulospinal Tract

Answer 3

Origin: pontine (excitatory from ascending spinoreticular sources) and medullary reticular formation, Side: , Influence: excitatory to extensor gamma motorneurons, General Facts:

Question 4

Rubrospinal Tract

Answer 4

Origin: red nucleus, Side:crosses in midbrain, only goes to cervical level of the spinal cord, Influence: excitatory to flexor motorneuron pools of the upper extremities, General Facts: minor in humans, for humans output from the red nucleus is mainly associated with parvocellular projections to the inferior olive

Question 5

Tectospinal Tract

Answer 5

Origin: deep layers of the superior colliculus, Side: crosses in midline of midbrain descends in the contralateral tectospinal tract, Influence: head and trunk positioning in response to visual stimulus, General Facts: works as the superior colliculus receives visual input

Question 6

UMN lesion clinical presentation

Answer 6

muscle stretch reflexes increased, muscle tone increased, muscle tissue maintained, muscles strength maintained, fine motor control markedly diminished, pathological reflexes present

Question 7

LMN lesion clinical presentation

Answer 7

Muscle stretch reflexes decreased, muscle tone decreased, muscle tissue atrophied, muscle strength diminished, fine motor control MINIMALLY diminished, pathological reflexes absent

Question 8

UMN “spasticity”

Answer 8

hyper-reflexia, increased muscle tone (resistance to passive movement at joint), babinski sign (involuntary extension of the great toe when the sole of the foot is scratched)