CorticoSpinal and Cortico Bulbar fibers-1

Question 1

Artery supply of hip and below on Primary motor cortex

Answer 1

Anterior Cerebral artery

Question 2

Broadman’s area 4 overlaps largely with

Answer 2

the precentral gyrus and the anterior paracentral, lobule

Question 3

Premotor cortex receives projections from

Answer 3

posterior parietal area BA-5,7 Basal Ganglia via thalamus cerebellumvia thalamus

Question 4

primary motor cortex receives input from

Answer 4

PSC - BA-3,1,2 Poterior parietal cortex BA-5,7(integrates sensory info for motor planning in concert with frontal areas Basal ganglia via thalamus and premotor area Cerebellum via thalamus

Question 5

the lateral aspects of the premotor cortex project to _______ and also contribute to ____________

Answer 5

pirmary motor cortex, corticospinal and coritcobulbar tracts.

Question 6

main function of the lateral corticopsinal tract is

Answer 6

voluntary contraction and relaxation of muscles but has a stronger influence over flexor muscles.

Question 7

mental rehearsing of a sequence is done by the

Answer 7

supplementary motor area

Question 8

finger flexion is done by the

Answer 8

motor cortex and somatosensory cortex

Question 9

sequence of finger flexions shows activity in

Answer 9

both supplementary and motor/somatosensory regions

Question 10

Lateral corticospinal tract originates in

Answer 10

pyramidal somata of layer 5 of the precentral gyrus and paracentral lobule (Broadman’s area 4)

Question 11

End of the corticospinal tract is

Answer 11

the contralateral spinal ventral horn where the axons of upper motor neurons synapse with the alpha and gamma lower motor neurons

Question 12

route of the corticospinal tract

Answer 12

cortex, corona radiata, internal capsule, crus cerebri, basilar pons, pyramids(medulla), pyramidal decussation, corticospinal tracts in spinal cord, synapses in alpha and motor neurons ins spinal ventral horn

Question 13

upper motor neurons commonly release

Answer 13

glutamate onto AMPA receptors either directly or indirectly sitmulating alpha and gamma lower motor neurons

Question 14

damage to corticospinal rostral to the pyramidal decussation produces

Answer 14

contralateral paresis

Question 15

damage to corticospinal tract caudal to the decussation produces

Answer 15

ipslateral paresis

Question 16

bilateral damage to the motor cortex or corticospinal and corticobulbar axons and initially lead to

Answer 16

muscular flaccidity and arreflexia which is called shock, (spinal shock if arising from spinal injury

Question 17

generally shock riddled spinal circuits caudal to lesion regain

Answer 17

function after a few weeks

Question 18

upper motor neuron lesion sumptoms

Answer 18

above DEC-contralateral below DEC-ipsilateral -Hyperreflexia- brisker than normal reflex -Extensor plantar response -first flaccid paralysis and later spastic paralysis(hypertonia) -no wasting muscle because 2nd motor neuron is not impaired -Clonus

Question 19

Lower motor neuron lesion

Answer 19

ipsilateral Hyporeflexia/areflexia- due to disruption of the eferent motor limb of the sensory motor reflex arcs. Hypotonia or atonia flaccid paralysis or paresis wasting of muscles Fasiculations fibrillations Examples ALS, Peripheral nerve trauma.

Question 20

Brown Sequard Syndrome

Answer 20

-CS tract- below lesion, upper motor syndrome usually occurs ipsilaterally ALS- contralateral loss of pain and temp DCML- loss of touch, vibration, proprioception ipslaterally below lesion LMN- Segmental syndrome occurs at the level of the lesion

Question 21

Paraplegia

Answer 21

ALL BILATERAL -Hyper reflexia -Extensor plantar response -transient flaccid paralysis below level of lesion followd by spastic paralysis -increased clonus -early transient retention of urin with painless destension of the bladder and overflow -paraplegia in flexion -loss of all somatosensation from below the lesion.

Question 22

Motor Homonuculus man

Answer 22