Descending Pathways

Question 1

The lateral corticospinal tract controls what muscles?

Answer 1

Distal limb muscles

Question 2

What descending pathway controls distal limbs?

Answer 2

Lateral CS tract

Question 3

What descending pathway controls the axial muscles?

Answer 3

Anterior CS tract

Question 4

Descending tract responsible for fine motor movements

Answer 4

Lateral CS tract

Question 5

Descending tract responsible for gross motor movements

Answer 5

Anterior CS tract

Question 6

Descending tract responsible for activating alpha motor neurons that supply the neck

Answer 6

ACST

Question 7

Wherdo ACST fibers end?

Answer 7

Spinal cord segment T1

Question 8

What percentage of CST fibers decussate at the pyramids (aka are apart of the LCST)?

Answer 8

85%

Question 9

When CST fibers synapse w/ pontine nuclei or synapse w/ motor nuclei of cranial nerves, they are what kind of tract?

Answer 9

Corticobulbar

Question 10

Corticobulbar tract fibers can synapse w/ what 2 things?

Answer 10

Pontine nuclei

or

cranial nerves

Question 11

Where do corticobulbar tract fibers go when they synapse w/ pontine nuclei?

Answer 11

Contralateral cerebellum

Question 12

What tract decussates at the pyramids?

Answer 12

LCST

Question 13

What tract doesn’t decussate at the pyramids, rather at the spinal cord itself

Answer 13

ACST

Question 14

Another name for the medial reticulospinal tract

Answer 14

Pontine reticulospinal tract

Question 15

Another name for the lateral reticulospinal tract

Answer 15

Medullary reticulospinal tract

Question 16

Reticulospinal tracts synapse w/ what type of neurons?

Answer 16

Gamma

Question 17

The ______ reticulospinal tract is excitatory to gamma motor neurons

Answer 17

medial reticulospinal tract

Question 18

The ______ reticulospinal tract is inhibatory to gamma motor neurons

Answer 18

lateral reticulospinal tract

Question 19

What muscles do the reticulospinal tract effect?

Answer 19

Anti-gravity muscles

Question 20

What pathway begins at the inner ear?

Answer 20

Vestibulospinal tract

Question 21

What tract innervates extensor muscles and inhibits flexor muslces in ipsilateral upper and lower limbs

Answer 21

Lateral vestibulospinal tract

Question 22

What tract innervates extensor muscles in the cervical region and stops at T1

Answer 22

Medial vestibulospinal tract (descending portion)

Question 23

What nuclei inhibit vestibulospinal tract extensor m. stimulation?

Answer 23

Red nuclei

Question 24

What tract controls the eyes during body movement?

Answer 24

Medial vestibulospinal tract (ascending portion)

aka

Medial Longitudinal Fasciculus tract

Question 25

What tract synapses w/ motor nuclei of CN III, IV, and VI?

Answer 25

Medial Longitudinal Fasiculus tract aka Medial vestibulospinal tract (ascending portion)

Question 26

What tract innervates flexor muscles of upper limb and terminate at T7-T8?

Answer 26

Rubrospinal tract

Question 27

What tract crosses in the venture tegmental decussation?

Answer 27

Rubrospinal tract

Question 28

What tract originates in the superior/inferior colliculi?

Answer 28

Tectospinal tract

Question 29

What muscles does the tectospinal tract effect?

Answer 29

Cervical (neck) muscles