Basal Ganglia Flashcards
Basal Ganglia
the basal ganglia are a group of nuclei of ?
-mostly
in the brains of vertebrates that act as a?
variety of functions including?
basal ganglia exert an ? on a number of motor systems and ?
varied origin
- telencephalon, embryological origin, with some diencephalon and mesencephalon elements
- cohesive functional unit
- voluntary motor control, procedural learning, and cognitive and emotional functions
- inhibitory influence/ release of this inhibition permits a motor system to become active
Primary functions of the BG
modulate?
- regulate
- make
- suppress
what contributions ?
movement
- amplitude, velocity, and initiation of movements
- postural adjustments during skilled movements
- unnecessary movements
cognitive and behavioral
… motor programs that you don’t want
… motor programs that you do want
inhibit
activate
Response Selection
response selection involves a ?
various? help resolve
competitive process between potential responses
sources of info/ competition
BG direct and indirect pathways
direct
indirect
excites the appropriate motor pathway
inhibits the other motor pathways
Pathways + neurotransmitters
neurotransmitters are what
activate each component of the pathways— some excite the system some inhibit
Two main outcomes for damage to the BG
reduced movement
failure to inhibit involuntary movement
Parkinson’s Disease
PD is a ?
neurodegenerative process that occurs in the basal ganglia and results in hypo kinetic movement disorder
The cause of Parkinson’s disease is?
-current consensus is that PD involves a ? in combo with ?
pathphysiology: lesions of the ? leads to degenerations of ?
chemical changes: reduction in
unknown
-genetic susceptibility/ undetermined environmental factors
substantia nigra/ dopaminergic neurons in the substantial nigra
dopamine
Parkinson disease symptoms:
tremor rigidity stooped posture postural imbalance mask-like face imprecise speech low volume
Diagnosis of PD is based on the presence of 4 major signs
- 4.
resting tremor
rigidity
bradykinesia
loss of postural reflexes
PD resting tremor
usually see in ? but may see in
rhythmic movements of a body part
- pill rolling
- limbs and head/ jaw, lips, tongue
PD rigidity
increased ?
in rigidity movements are ? and may be ?
.. rigidity (jerky resistance to ? ) is common
involuntary resistance to passive movement
- slow and tiff/ initiated or stopped with difficulty
- cogwheel/ passive stretch
Bradykinesia:?
hypokinesia:
-… facial expression
-reduced
-
-festinating ?
akinesia:
slowness of movement; delayed initiation of movement
reduced movement
- mask like facial expression
- arm swing, gestures during speech
- micrographia
- gait; short rapid shuffling steps
absence of movement; impaired initiation of movement
Loss of postural reflexes:
poor adjustment to ?
.. posture
falling, difficulty moving from a sitting to standing position, unsteady gait
stooped posture (flexed head and trunk)
