Module 18 Flashcards
Where does the cerebellum get input from?
Muscles spindles
GTO
Where does the cortex sends output from motor systems to where?
Cerebellum
BG
What are the two descending motor pathways?
Pyramidal system (direct)
Extrapyramidal system (indirect)
Describe the pyramidal motor system
Carries only UMNs
Descend through:
Corona radiate
Internal capsule
Cerebral peduncles
Where does the fibers of the pyramidal system come from?
1/3 come from area 4
1/3 come from area 6
1/3 come from 3-1-2 & 5
What are the difference between LMN & UMN?
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
In the Corticobulbar pathway, the UMN synapse on which nerves?
Cranial nerves
LMN INNERVATE HEAD & face
In the Corticospinal pathway, the UMN synapse on which nerves?
Spinal nerves
Innervate limbs and trunk
What does the lateral corticospinal do? What about the anterior corticospinal do?
Lateral: SKILLED movement of limbs
Creates flexor behavior
Inhibits extensor behavior
Anterior: control of axial musculature
(Neck, shoulder, trunk)
What is the extrapyramidal system?
Indirect motor system
Name the pathways of the extrapyramidal system
cortico- reticulospinal
Cortico- rubrospinal
Vestibulospinal
Cortico- tectospinal
Where do the fiber from the corticoreticulospinal pathways originate? Where do they go?
In area 6
crossed/uncrossed go to the brainstem
What’s the role of the extrapyramidal system?
Innervate with axial/proximal musculature (limbs/trunk/neck)
What is the role of the reticulospinal pathway?
Maintaining upright posture
Facilitate/inhibit reflex AND voluntary movements
Where do the corticorubrospinal pathway originate? Where do they go?
Originate from area 4 and 6
Go to red nucleus of the midbrain
What is the role of the corticorubrospinal pathway?
Facilitates flexor muscle contraction
Inhibits extensor muscle contraction (upper body extremities)
Where do the lateral/medial components of the vestibulospinal pathways originate? Where do they go?
Lateral: pons/medulla junction (from lateral nucleus)
Medial: medial nucleus of BS
Where do the vestibular nuclei receive input and where does it go?
From inner ear/cerebellum
To: cerebellum/SC/BS Nuclei
What is the role of the vestibulospinal pathway?
Excite stretch receptors
Maintain tone of extensor muscles of trunk/back/limbs
Maintain posture/balance( same as corticoreticulospinal)
Where do the corticotectospinal pathway originate? Where does it go?
From: 18/19
To tectum
What is the role of the corticotectospinal?
Coordinate eye movement during balance activities (like dancing)
What are the 3 functional groups of motor (direct/indirect) pathways?
Lateral group (lateral descending) Anteromedial group (medial descending) Aminegic group
Which extrapyramidal pathways are a part of the lateral group?
Lateral corticospinal and rubrospinal pathways
Does lateral group influence the IPSILATERAL side or contralateral side?
Contralateral side
Which extrapyramidal pathways are apart of the anteromedial group?
Anterior corticospinal
Lateral/medial reticulospinal
Lateral/medial vestibulospinal
What are the roles of the 3 functional groups?
Lateral: make independent finger movements
Anteromedial: coordination axial & Lomb girdle muscles during postural movements
Aminergic: modulates LMN excitability
