Workshop 5 BSG/PD Flashcards
(38 cards)
Upper Motor Neuron Cell Bodies situated where?
Pre-Central Gryus- Motor Cortex
LMNs located?
ventral horn of the gray matter
Motor nucluei of cranial nerves in the brainsteam
BSG Def
group of subcortical nuclei, base of forebrain
BSG and Cerebellum are Diff to other motor system as
they modulate movement
other functions in addition to modulating motor control
Damaged BSG leads to
damaged in primary motor structures
BSG Functions-
Dont directly LMNS
Regulate activity of UMNs
Prevenet UMNs from iniating unwanted movements
Prepare motor cirucits for initation
Regulate transition from 1 pattern to another of voluntary movements
BG Anatomy
Striatum(forebrain)
Dorsal Stratium
Caudate Nuclues & Ventral Straitum=Nucleus Accumbens)
Globus Pallidus: Base of forebrain:
Internal, External Segment
Subthalamic Nucleus
Susbtantia nigra
Functional Classification Intrinsic Nuclei:
Globus Pallidus(external)
Subthalamic Nucleus
Substantia nigra
Functional Classification Intrinsic Nuclei:
Globus Pallidus(external)
Subthalamic Nucleus
Substantia nigra
Functional Classification- Striatum(Input Nuclei)
Caudate Nucleus
Putamen
Nucleus Accumbens
BSG Functions
-Modulate and Regulate Activity
Goal Directed Movement
Motor Learning
Motor Pattern Selection
Fine tuning the starting and stopping voluntary movements
Preventing unwanted movements
Procedural Learning ie: complex patterns/sequences of movement
Planning and controlling movement intensiitees an directions
eye movements
cognition
emotions
Motor Loops
BG work with other CNS regions to modulate movements both before and during their execution
Actions effected via body movements and Oculomotor
Putamen
acts as a reservoir for learning motor programs
assembles an approipiate motor sequence for desired movements
info is sent to the Supplementary Motor Area
Damage to the Substania Nigra
inhibition of the direct pathways and dishibition of the indirect pathway
Functional Classification Output Nuclei:
Globus Pallidus (internal)
Subthalamic Nucleus
Substania Nigra
BG: Functional Connections Step by Step
Cerebral Cortex, Thalamus, Limbic System send excitatory information to input nuclei
Information is processed and sent to the intrinsic nuclei
Input Nuclei process & pass info output nuclei
Output Nuclei send info to thalamus
Thalamus relays info to motor cortex
Resting State
Globus Pallidus Internal inhibits the motor thalamic neurons hence no output to upper motor neurons in the motor cortex
Direct Pathway:
Reduced Inhibition of Thalamic Neurons
Increased Thalamic Output to Cortex
Increased Motor Cortex Output
Increased Motor Activity in Corticospinal tract
Increased Movement
Indirect Pathway
Increased Inhibition of Thalamic Neurons
Reduced thalamic Output to Cortex
Inhibition of Motor Cortex
Reduced Motor activity in corticospinal tract
Reduced Movement
Role of the Substantia Nigra
Turns up the Direct and Turns Down the Indirect
Less Thalamic Inhibition
Increased thalamic Output to Motor Cortex
Increased Activity in the Motor Cortex
Increased Output in the Corticospinal Tract
Increased Movement
Motor learning involves what structures?
Prefrontal (cognitive)
Head of Caudate Nucleus receives projections from the prefrontal cortex and appears to participate in motor learning
Limbic Loop role?
giving motor expression to emotions
High in dopamine
PD Etiology
idiopathic degeneration of the dopamine producing cells in the substantia nigra resulting in reduced dopamine production
PD Initial Motor Stages
Akinesia
Bradykinesia
Rigidity
Resting tremor
Decreased mm power
Impaired automatic postural responses to position and movement
