Parkinson's Disease Flashcards
What is declarative memory?
Factual information.
Life events.
Available to consciousness.
Easily formed and forgotten.
What is non-declarative memory?
Procedural memory.
Motor skills.
Not available to consciousness.
Less easily formed, but harder to forget.
What is ballistic movement?
Movement based on pre-programmed instructions.
Rapid - but at the expense of accuracy.
What are Pursuit Visual feedback movements?
Motor command is continually updated according to sensory feedback (visual).
Highly accurate as can be modified in progress, but slow.
What is the function of the prefrontal cortex? Where is it located?
Makes the decision to make a movement.
Found at the front of the frontal lobe.
What is the function of the primary motor cortex? Where is it located?
Generates impulses to control the execution of movement.
In the frontal lobe in the precentral gyrus.
Motor homunculus.
What is the function of the supplementary and premotor cortex? Where are they located?
For planning movements.
Anterior to the primary motor cortex.
In a finger moving task, which areas of the brain would exhibit activity?
If just mentally rehearsing the movement, where would activity be seen?
SMA, M1 and S1.
SMA only.
Explain how sensory information is important for co-ordinated movement.
Proprioception: feedback from sensory receptors (muscle spindles) about the position and movements of limbs.
Vision: Eyes, visual system and visual cortex.
Vesibular: Feedback from organs of balance.
What is the main non-cortical structures involved in movement?
The basal ganglia.
What is the main input of the basal ganglia?
Prefrontal cortex.
What is the main output of the basal ganglia?
Pre-motor area via the thalamus.
What are the functions of the basal ganglia?
Grey matter nuclei deep beneath the cerebral cortex.
Initiation of movement by putting the motor plan into action.
Planning of complex voluntary movement.
Inhibit unwanted movments.
Posture and muscle tone.
What is the main input of the cerebellum?
Input from the sensory cortex.
What is the main output of the cerebellum?
Primary motor cortex via thalamus.
What are the functions of the cerebellum?
Coordination and smooth execution of movements.
Motor learning and error detection.
What are the lateral descending pathways for motor movement?
What is there function and location?
Corticospinal and ruberospinal tract.
Control voluntary movement e.g. fine movement of hand.
Run in the lateral funiculus.
What are the ventromedial descending pathways for motor control function? Where do they run?
Reticulospinal and vestibulospinal.
Control axial muscles and posture.
Run in the ventral funiculus.
What is a motor unit?
A motor neuron and all the fibres it innervates.
What makes up the striatum?
Caudate nucleus and lentiform nucleus.
What makes up the lentiform nucleus?
Putamen and Globus Pallidus.
What makes up the corpus striatum?
Caudate nucleus, putamen and globus pallidus.
Describe the pathway of the lateral descending motor pathways?
Prefrontal cortex Thalamus Basal Ganglia Thalamus Premotor Area 6 Primary Motor cortex 4 Spinal cord lateral funiculus - Ruberospinal and Corticospinal tracts.
Describe the pathway of ventromedial descending motor pathways?
Sensory cortex Cerebellum Thalamus Primary Motor cortex 4 Spinal cord in ventral funiculus as Reticulospinal and Vesibulospinal tracts.
Name the extra-pyramidal tracts.
Vestibulospinal, Reticulospinal, Rubrospinal and Tectospinal.
How is Dopamine synthesised?
Tyrosine enters the neuron via active transport.
In the cytoplasm, tyrosine is converted to DOPA via tyrosine hydroxylase.
DOPA is then converted to dopamine by DOPA de-carboxylase.
Dopamine is then actively transported into storage vesicles by the vesicular transport system.
How is dopamine released and what is its fate?
Dopamine is released to the synaptic cleft.
It is then either actively transported to the neurone terminal - reuptake 1.
FINISH
Name the 4 main dopaminergic pathways in the brain?
Nigrostriatal pathway
Mesolimbic pathway
Mesocortical pathway
Tuberohypophyseal System
Descibe the Nigrostriatal pathway?
Accounts for 75% of dopamine in the brain.
Cell bodies are mainly in the Substansia Nigra.
Axons terminat in the corpus striatum.
Fibres run in the medial forebrain bundle.
Describe the Mesolimbic pathway?
Cell bodies are in the midbrain ventral tegmental area adjacent to the substania nigra. Project via the medial forebrain bundle to parts of the limbic system (nucleus accumbens and the amygdaloid nucleus).