UMNs

Question 1

Cell bodies are located where?

Answer 1

Motor Cortex
OR
Brainstem

Question 2

UMNs that arise from Brainstem project to…

Answer 2

Medial ventral horn

Question 3

UMNs that arise from Motor Cortex project to

Answer 3

Lateral ventral horn

Question 4

Which pathways go Brainstem –> Medial horn (3)

Answer 4

Vestibulospinal
Reticulospinal
Colliculospinal

Question 5

Which pathway goes Cortex –> Lateral horn

Answer 5

Lateral Corticospinal

Question 6

Which pathway goes Brainstem –> Lateral horn

Answer 6

Rubrospinal

Question 7

Vestibulospinal Tract function

Answer 7

Balance & posture

Question 8

Medial Vestibulospinal Pathway

Answer 8

1. Semi Canals & Otolith –> Vestibular Nuclei (CN 8).

2. Vestibular –> Medial cord (BILATERAL)

Question 9

Reticulospinal Tract function

Answer 9

Balance & posture

Question 10

Reticulospinal Pathway

Answer 10

Reticular Formation (pons + medulla) –> Medial cord

Question 11

Difference between Vestibulospinal & Reticulospinal

Answer 11

Vestibulo uses FeedBack - responds to postural changes.

Reticulo uses FeedForward - postural adjustments to stabilize before/during movement.

Question 12

Colliculospinal Tract function

Answer 12

Head/neck movement

Question 13

Colliculospinal Pathway

Answer 13

1. Optic tracts –> Superior Colliculus (midbrain)

2. Superior Colliculus –> Medial C-spinal cord

Question 14

Rubrospinal Tract function

Answer 14

Arm/shoulder movement

Question 15

Rubrospinal Pathway

Answer 15

1. Red Nucleus (midbrain) –> intermediate & lateral C-spinal cord

Question 16

Motor Cortex receives input from (3)

Answer 16

Basal Ganglia
Cerebellum
Sensory

Question 17

Corticospinal projects from Cortex –>

Answer 17

Spinal Cord

Question 18

Corticobulbar projects from Cortex –>

Answer 18

Brainstem

Question 19

Primary Motor Cortex fires when?

Answer 19

During movement

Question 20

Premotor Cortex fires when?

Answer 20

Before movement

Question 21

Lateral Premotor Cortex (PMA) invx which muscles? Selects movements based on what?

Answer 21

Proximal

Based on external events

Question 22

Medial Premotor Cortex (SMA) invx which muscles? Selects movements based on what?

Answer 22

Distal

Based on internal cues

Question 23

Corticospinal Tract function

Answer 23

Trunk/extremity movement

Question 24

Lateral Corticospinal Pathway

Answer 24

1. Axons –> Internal Capsule –> Cerebral Peduncles –> Pons –> Medulla.
2. Cross in Caudal Medualla.
3. Synapse on alpha-Motor N in lateral ventral horn.

Question 25

Ventral Corticospinal Pathway

Answer 25

1. Axons --> Internal Capsule --> Cerebral Peduncles --> Pons --> Medulla. 2. Some do not cross. 3. Synapse on axial muscle N pools. 4. Some send collaterals that cross over for bilateral trunk motion.

Question 26

Corticobulbar Tract function

Answer 26

Head/neck movement

Question 27

Corticobulbar Pathway

Answer 27

1. Axons synapse on CN Motor Nuclei | Some CN receive bilateral, others receive from contralateral Cortex

Question 28

Upper Facial Motor Nucleus: receives bilateral or contralateral invx?

Answer 28

Bilateral

Question 29

Lower Facial Motor Nucleus: receives bilateral or contralateral invx?

Answer 29

Contralateral

Question 30

Facial Paralysis symptoms

Answer 30

Lower muscles on contralateral side - weak/paralyzed. | Upper muscles on both sides - intact.

Question 31

UMN Syndrome Phase 1

Answer 31

Acute/Spinal Shock Flaccidy & hypotonia on contralateral side. Muscle activity & reflexes temporarily lost.

Question 32

UMN Syndrome Phase 2

Answer 32

``` Consistent Pattern After several days, circuits regain function. Babinski & Clonus. Hypertonia & Hyperreflexia. Loss of fine motor movement. ```