Descending Tracts

Question 1

Pontine Reticulospinal Tract function? Descends?

Answer 1

Facilitates motor neurons to axial and limb Extensors; IPSILATERAL

Question 2

Medullary Reticulospinal Tract function? Descends?

Answer 2

Inhibit/ excite motor neurons to cervical muscles and excites motor neurons to back muscles; BILATERALLY

Question 3

Reticuloformation receies input from motor cortex, cerebellum, and brain stem nuclei. Functions?

Answer 3

Fixing a posture, Stabilization of proximal limb joints so voluntary movement of distal limbs can occur.

Question 4

Lateral Vestibulospinal tracts terminates _____ in the ventral horn. Effects _____ muscles (maintains blance and upright posture)

Answer 4

Ipsilaterally; antigravity

Question 5

Does Lateral Vestibulospinal tract cross?

Answer 5

NO

Question 6

Medial Vestibulospinal tract descends _____ within MLF

Answer 6

Bilaterally

Question 7

Is Lateral Vestibulospinal tract found in all cord segments?

Answer 7

Yes, ALL

Question 8

Is Medial Vestibulospinal tract found in all cord segments?

Answer 8

NO; cervical and thoracic levels (maintains head position in response to VESTIBULAR RESPONSE when moving)

Question 9

Tectospinal tract originates in the superior colliculus of _____

Answer 9

Midbrain

Question 10

Tectospinal tract crosses in the ______.

Answer 10

Dorsal tegmental decussation

Question 11

Tectospinal tract terminates in _____ segments.

Answer 11

Cervical cord

Question 12

Tectospinal tract function?

Answer 12

Reflex head movements in response to visual, auditory, cutaneous stimuli. (TRACKING A VISUAL STIMULUS)

Question 13

Rubrospinal tract originates in?

Answer 13

Red nucleus of the midbrain

Question 14

Rubrospinal tract crosses at the ______.

Answer 14

Ventral tegmental decussation

Question 15

Rubrospinal tract extends to _____ cord in humans. (Not found in all cord segments)

Answer 15

Cervical

Question 16

Rubrospinal tract function?

Answer 16

Facilatates flexor and inhibits extensor motor neurons. (Flexion)

Question 17

Descending autonomic fibers originate from _____ and brain stem nuclei.

Answer 17

Hypothalamus

Question 18

Descending autonomic fibers terminates on _____ neurons

Answer 18

Preganglionic

Question 19

Aminergic pathways (raphespinal) originate in_____ formation

Answer 19

Reticular

Question 20

Aminergic pathways (raphespinal) terminates in?

Answer 20

Dorsal horn

Question 21

Corticospinal tract is part of _____ system

Answer 21

pyramidal

Question 22

Corticospinal tract originates in? (Many)

Answer 22

Motor, premotor, supplementary, postcentral gyrus, paracentral lobule

Question 23

Corticospinal tract function?

Answer 23

Provides skill, precision, speed, and agility during voluntary movements.

Question 24

Corticospinal tract 85-90% cross in the _____ decussation. 10-15% descend uncrossed as ventral corticospinal tract but cross before terminate in gray of cervical and upper thoracic segments.

Answer 24

Pyramidal

Question 25

Corticospinal tract terminates on ___ and ___ motor neurons and on interneurons.

Answer 25

Alpha and gamma motor neurons