GA: Basal Ganglia Flashcards
These components form what?
- Caudate
- Putamen
- Globus Pallidus
- Subthalamic nucleus
- Substantia nigra
Basal Ganglia
What is the function of the caudate?
eye mvmts + cognition
What is the function of the putamen?
motor function
What is the function of the globus pallidus?
-has internus (medius) & externus (lateralis)
Main output
The substantia nigra has 2 parts: pars reticulata + pars compacta, what are there functions?
In general: substantia nigra = input/output
pars reticulata = output
pars compacta = input
What makes up the striatum in the basal ganglia?
Caudate (eyes) + Putamen (motor)
What makes up the lenticular nucleus in the basal ganglia?
Putamen (motor) + Globus Pallidus (output)
What makes up the ventral striatum (input) in the basal ganglia?
Nucleus accumbens (emotion) + Olfactory tubercle
What makes up the ventral pallidum in the basal nuclei?
Substantia innominata
Where is:
- head of caudate nucleus
- internal capsule
- putamen
- globus pallidus
- ventral striatum
- ventral pallidum
What passes through the post. limb? and under?
Through = lenticular fasciculus
Under = ansa lenticularis
What 3 things make up the input nuclei of the basal ganglia?
- caudate nucleus
- Putamen
- Nucleus acumbens
What is the function of the nucleus accumbens?
Mediates emotions
What 3 things make up the output nuclei of the basal ganglia?
- Internal segment of globus pallidus (motor - limb + trunk control)
- Substantia nigra pars reticulate (cognition + eye control)
- Ventral pallidum (emotions)
Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas. The basal ganglia are associated with a variety of functions, including control of voluntary motor movements, procedural learning, habit learning, eye movements, cognition, and emotion.
What is the order of which information flows in the basal ganglia?
What is the direct pathway of the basal ganglia?
What is the indirect pathway for the basal ganglia?
- what is inhibitory?
- striatum = putamen
Ex. of indirect pathway = If you are kicking a ball, it prevents all that unwanted mvmt from coming through
The Direct + indirect pathways are part of what parallel circuit?
Skeletomotor loop
-Role in the control of facial, limb, and trunk musculature
Which parallel circuit controls saccadic eye movements?
Oculomotor loop
Which parallel circuit has a role in ocgnition + executive behavior functions?
Associative loop
Which parellel circuit participates i the motivational regulation of behavior and in emotion + motivation?
Limbic loop
-Ventral striatum = nucleus accumbens
What causes Parkinsons Disease?
Neurons from the substantia nigra do not release enough dopamine onto basal ganglia and the cells die
Possibly treat with dopamine?
-In picture the substantia niagra has died
Is Parkinson’s a hypo- or hyper- disorder?
hypo
- hypokinesia (decreasing range of mvmt)
- bradykinesia (slow mvmt)
- A mask-like facial expresion
- Pill-rolling tremor
- Flexion of trunk
- slow, shuffiling mvmts
- rigidity
- visuoperceptive impairments
Parkinson’s
What causes the hypokinetic effect of Parkinsons’s?
Too little direct pathway or too much indirect pathway
When does Parkinsons’s start?
Progressive disease striking victims at age 60
When do you see symptoms of Huntingtons? Is it genetic?
Huntington’s = HOUSE
Huntington;s is a progressive disease with onset at age 45.
It is AD! (not good)
What causes Huntington’s?
Degeneration of neurons in the striatum (caudate + putamen) + cerebral cortex resulting in decreased GABA. –> can’t inhibit mvmts
Involuntary, jerky, rapid movements, and dementia describe what disease?
-also they can’t stick out their tongue
Huntington’s
How do you treat Huntington’s?
Tetrabenazine (seratonin antagonist)
What other things can cause hyperkinetic disorders besides huntington’s?
Sydenham chorea (untreated strep)
-Graves (thyrotoxicosis
Chorea
Athetosis
Ballismus
Dystonia
All describe what type of disorder?
Hyperkinetic movement disorders
Spontaneous, rapid, jerky, arrhythmic involuntary mvmts which are not on purpose describe what?
Chorea
Inability to sustain the body part in one position, or continual slow “snake-like” mvmts describes?
Athetosis
Uncontrolled flailing/flinging of an extremity often seen in lesions of the contralateral subthalamic nucleus describes?
Ballismus
An arm getting “stuck” in one position describes?
Dystonia
Why do hyperkinetic disorders occur?
When there is not enough indirect pathway effect
