Tracts: motor/descending

Question 1

Origin of anterior roots

Answer 1

anterior horn of spinal cord, lamina IX, Lower motor neurons

Question 2

target for anterior roots

Answer 2

skeletal muscle

Question 3

Function for anterior roots

Answer 3

direct voluntary control of skeletal muscle

Question 4

Signs/Symptoms of Injury to Anterior Roots

Answer 4

Weakness, Atrophy, Hyporeflexia, Fasciculation

Question 5

Major Inputs for Lateral Corticospinal Tract

Answer 5

Premotor, Striatum, VA/VL Thalamus

Question 6

Origin of Lateral Corticospinal Tract

Answer 6

Cortex (primary motor, somatosensory and premotor)

Question 7

Course of Lateral Corticospinal Tract

Answer 7

Internal capsule, Crus cerebri, basilar pons, pyramids, spinal cord

Question 8

Where does Lateral Corticospinal Tract Decussate

Answer 8

Pyramidal decussation (medulla), 90% of axons

Question 9

Target of Lateral Corticospinal Tract

Answer 9

ALL spinal cord levels; end mostly interneurons in the anterior horn; some on alpha motor

Question 10

Function of Lateral Corticospinal Tract

Answer 10

voluntary motor control, esp distal limbs

Question 11

S&S of injury to Lateral corticospinal tract

Answer 11

weakness, spasticity, hyper-reflexia, clonus, pronator drift and babinski

Question 12

Where Anterior Corticospinal Tract decussates

Answer 12

Anterior white commissure at level of termination

Question 13

Target for Anterior Corticospinal Tract

Answer 13

End at thoracic levels; fwe to lumbar levels

Question 14

Fx of Anterior Corticospinal Tract

Answer 14

Voluntary Motor Control, Trunk

Question 15

Course of Corticonuclear (bulbar) Tract

Answer 15

Internal capsule, cerebral peduncles, basilar pons, pyramids

Question 16

Corticonuclear (bulbar) tract decussates where?

Answer 16

Brainstem (most axons partake in a broad, diffuse crossing)

Question 17

voluntary control of motor cranial nerves

Answer 17

Corticonuclear (bulbar) tract

Question 18

CL input from Corticonuclear (bulbar) tract

Answer 18

1. Facial nucleus neurons innervating muscles of lower face
2. Neurons innervating genioglossus
3. Neurons innervating the soft palate and uvula in the nucleus ambiguus

Question 19

S&S from Corticonuclear (bulbar) tract

Answer 19

Lower facial paralysis (contralateral to lesion), tongue hemiparesis (deviates to contralateral side), sagging palate (contralateral), dysphagia

Question 20

Where does the corticopontine tract decussate

Answer 20

basilar pons and run in middle cerebellar peduncle

Question 21

Target of Corticopontine Tract

Answer 21

Dentate Nucleus

Question 22

Tract associated with motor programming/planning

Answer 22

Corticopontine tract

Question 23

Lesion to Corticopontine tract

Answer 23

asynergy, dysdiadochkinesia, dysmetria, decomposition of movements

Question 24

Origin of Rubrospinal Tract

Answer 24

Red nucleus (Magnocellular)

Question 25

Decussates at anterior tegmental decussation

Answer 25

Rubrospinal Tract

Question 26

Flexor tone in UL

Answer 26

Rubrospinal Tract

Question 27

Facilitates extensor tone

Answer 27

Pontine [Medial] Reticulospinal

Question 28

Origin of Medullary (lateral) reticulospinal tract

Answer 28

Gigantocellular nucleus

Question 29

inhibits externsor tone, respiratory, cardiovascular

Answer 29

Medullary (lateral) reticulospinal tract

Question 30

Tract that stabilizes the head

Answer 30

medial vestibulospinal tract

Question 31

facilitates extensors of trunk/proximal limbs

Answer 31

Lateral Vestibulospinal tract

Question 32

2 Tracts associated with orienting to aud/visual stimuli

Answer 32

Tectospinal and Tectobulbar tract

Question 33

Lesion to hypothalamospinal tract

Answer 33

Horner Syndrome