Last minute Flashcards
(26 cards)
The cell bodies of the UMN that form the descending motor pathways to the brainstem and spinal cord are known as the?
Layer V internal pyramidal layer of the cerebral cortex.
Where do the UMN of the corticospinal tract dessecate?
Dessecates within the pyramids of the medulla to form the lateral corticospinal tract and the anterior cortico spinal tract.
NOT ALL DESSECATE, 10% CONTINUE AS THE ANTERIOR CORTCOSPINAL TRACT TO AXILA.
Which side of the body do the corticospinal tracts control?
The contralateral side after passing through the medulary pyramids!
Fasciculations and fibrulations are part of what motor neuron sign?
Part of a lower motor neuron sign.
Broadmans area 3,1,2 refers to what?
Precentral gyrus home of the primary somatosensory cortex.
What is the order of the cortcospinal pathway?
Cortex Corona Radiata Posterior limb of internal capsule Basis Perduncle Pons Medulla (pyramid)
What deficits are seen in a loss of the lenticulate artery?
Motor deficits in the contralateral side of the body.
What blood supplies the basis pedunculi?
Posterior cerebral artery.
Where is the corticotecto nuclei located and where does it travel?
Located in the occipital lobe and travels to occulomotor acessory nuclei and the superior colliculus.
Where is the tectospinal tract nuclei located and what is its path.
Tectospinal tract is in the superior colliculi and travels to the upper cervical spine for reactive movment.
The corticotectal tract has its origins in which bragman areas?
Visual association corted areas 18 and 19.
Where does the rubrospinal nerve cross?
Crosses in the midbrain and then descends to upper spinal cord.
What is the pathway for the corticoreticulo tract
From the motor cortex to the brainstem reticular formation (within the pins and medulla)
Where does the medial reticulospinal tract flow?
Arises from the pontine nuclei that descends ipsilaterally to all spinal cord levels within the anterior faniculis.
Where does the reticulospinal tract cross?
It never crosses!
Descends in anterior funiculus and synapses in the gray matter with interneurons and gamma neurons stimulating extensors and inhibiting flexors.
What is the path of the lateral reticulospinal tract?
from the medulary nucleus and Descends ipsilaterally and inhibits the limb extensors!
Medial vs lateral vestibulospinal tracts
Lateral - Excitatory to antigravity muscles terminating ipsilaterally at all levels.
Medial - Bi-lateral termination at cervical and upper
controls head movements.
Lateral vs. Medial reticulospinal tracts
MEdial - ipsilateral descendance in anterior funiculus excitiatory to paravertebral limb extensors.
-Lateral - Inhibitory on paravertebral extensors.
Polymyeltis affects which nerves?
Affects the LMN and will display LMN signs.
Viral infection.
Combined systems disease?
Lack of B12
Degenerates dorsal funiculus (FG and FC)
and the
Lateral funiculus ( Motor fibers of the corticospinal tract) will display UMN signs.
Brown Sequard syndrome?
Hemisection -
Loss of discriminative at and below ispilaterally.
Loss of pain and temp 2 segments below contralaterally.
oss of reflex ipsilaterally
UMN signs below level of lesion ipsilaterall
LMN signs at the level ipsilaterally.
The nucleus ambigus serves which cranial nerves?
Serves cranial nerves 9 and 10 bilaterally.
The acessory nucleus serves the acessory nerve from which side of body?
Serves ipsilaterally!
Where do the motor fibers to CN 3,4,6 receive nervous information from?
DO NOT RECIVE CORTICONUCLEAR INNERVATION.
Nervous supply comes from frontal and parietal motor eye fields and make a stop in reticular formation that projects to these nuclei.
