Module 18

Question 0

Where does the cerebellum get input from?

Answer 0

Muscles spindles

GTO

Question 1

Where does the cortex sends output from motor systems to where?

Answer 1

Cerebellum

BG

Question 2

What are the two descending motor pathways?

Answer 2

Pyramidal system (direct)

Extrapyramidal system (indirect)

Question 3

Describe the pyramidal motor system

Answer 3

Carries only UMNs

Descend through:
Corona radiate
Internal capsule
Cerebral peduncles

Question 4

Where does the fibers of the pyramidal system come from?

Answer 4

1/3 come from area 4
1/3 come from area 6
1/3 come from 3-1-2 & 5

Question 5

What are the difference between LMN & UMN?

Answer 5

LMN- innervate voluntary muscles
UMN- innervate/influence LMNs

LMN- from BS/SC to muscles
UMN- from cortex to BS/SC LMN

UMN- direct/indirect connection to LMN

Question 6

In the Corticobulbar pathway, the UMN synapse on which nerves?

Answer 6

Cranial nerves

LMN INNERVATE HEAD & face

Question 7

In the Corticospinal pathway, the UMN synapse on which nerves?

Answer 7

Spinal nerves

Innervate limbs and trunk

Question 8

What does the lateral corticospinal do? What about the anterior corticospinal do?

Answer 8

Lateral: SKILLED movement of limbs
Creates flexor behavior
Inhibits extensor behavior

Anterior: control of axial musculature
(Neck, shoulder, trunk)

Question 9

What is the extrapyramidal system?

Answer 9

Indirect motor system

Question 10

Name the pathways of the extrapyramidal system

Answer 10

cortico- reticulospinal

Cortico- rubrospinal

Vestibulospinal

Cortico- tectospinal

Question 11

Where do the fiber from the corticoreticulospinal pathways originate? Where do they go?

Answer 11

In area 6

crossed/uncrossed go to the brainstem

Question 12

What’s the role of the extrapyramidal system?

Answer 12

Innervate with axial/proximal musculature (limbs/trunk/neck)

Question 13

What is the role of the reticulospinal pathway?

Answer 13

Maintaining upright posture

Facilitate/inhibit reflex AND voluntary movements

Question 14

Where do the corticorubrospinal pathway originate? Where do they go?

Answer 14

Originate from area 4 and 6

Go to red nucleus of the midbrain

Question 15

What is the role of the corticorubrospinal pathway?

Answer 15

Facilitates flexor muscle contraction

Inhibits extensor muscle contraction (upper body extremities)

Question 16

Where do the lateral/medial components of the vestibulospinal pathways originate? Where do they go?

Answer 16

Lateral: pons/medulla junction (from lateral nucleus)

Medial: medial nucleus of BS

Question 17

Where do the vestibular nuclei receive input and where does it go?

Answer 17

From inner ear/cerebellum

To: cerebellum/SC/BS Nuclei

Question 18

What is the role of the vestibulospinal pathway?

Answer 18

Excite stretch receptors
Maintain tone of extensor muscles of trunk/back/limbs
Maintain posture/balance( same as corticoreticulospinal)

Question 19

Where do the corticotectospinal pathway originate? Where does it go?

Answer 19

From: 18/19

To tectum

Question 20

What is the role of the corticotectospinal?

Answer 20

Coordinate eye movement during balance activities (like dancing)

Question 21

What are the 3 functional groups of motor (direct/indirect) pathways?

Answer 21

Lateral group (lateral descending) 
Anteromedial group (medial descending) 
Aminegic group

Question 22

Which extrapyramidal pathways are a part of the lateral group?

Answer 22

Lateral corticospinal and rubrospinal pathways

Question 23

Does lateral group influence the IPSILATERAL side or contralateral side?

Answer 23

Contralateral side

Question 24

Which extrapyramidal pathways are apart of the anteromedial group?

Answer 24

Anterior corticospinal

Lateral/medial reticulospinal
Lateral/medial vestibulospinal

Question 25

What are the roles of the 3 functional groups?

Answer 25

Lateral: make independent finger movements

Anteromedial: coordination axial & Lomb girdle muscles during postural movements

Aminergic: modulates LMN excitability