Function of Reticular Formation?
- -Integrates incoming sensory info
- -activates/arouses cerebral cortex
- -regulate muscle reflexes
What 4 brain structures comprise the motor related areas of the cerebral cortex?
- Primary motor cortex (B4)
- Premotor cortex (B6
- Supplementary motor cortex (B6)
- Pre-supplementary motor cortex
What is the function of the primary motor cortex?
Voluntary movement, humunculus, contralateral movement
What does a lesion to the primary motor cortex do?
Paralysis of "ordered"/planned movement
What is the function of the premotor cortex?
Coordination of complex movement & orientation towards target
What happens when a lesion of the premotor cortex occurs?
No spatial awareness
What is the function of the supplementary motor cortex
Programming of complex tasks and bilateral motions.
What symptoms occur after a lesion of the supplementary motor cortex?
No paralysis, but a decrease in performance of complex tasks.
What are the functions of the pre-supplementary cortex?
Initiates unconsciously, voluntary movement.
What happens if a transection is made between the red nucleus and cerebral cortex in the rubio/reticular spinal tract?
Patient looses fine movements, but retains coarse movements.
Name the three structures of the cerebellum involved in movement. Give their function
- -Vestibulocerebellum: Important for balance and eye movements. Allows the eye to see moving objects while moving.
- -Cerebrocerebellum: Planing and initiating voluntary movement by providing input to cortical motor areas and stores procedural memories. Also, sends info back to the cortex through the thalmus
- -Spinocerebellum: enhances muscle tone and coordinates skilled, control and correction of ongoing movements. Actively compares "orders" to actual movements.
What is observed when a patient's spinocerebellum has been lesioned?
- Intentional tremors: only present during voluntary movement.
- Dysmetria: lack of coordination due to the inability to judge distances.
What is the function of the thalamus?
A relay station. A synaptic integrating center for all sensory input heading to the cortex. Positively reinforces voluntary motor behavior from the cortex
initiation, planning, and programming of movements. inhibits muscle tone and unwanted movements. Monitor but not directly influence efferent neurons
What are the 4 parts of the basal ganglia and what are their functions?
- -striatum: caudate nucleus and putamen.
- -globus pallidus: external and internal part. all output goes through internal g.p.
- -subthalamic nucleus
- -substantia nigra: (Parkinsons) releases dopamine and Noradrenaline/norepineephrine into striatum.
What is the pathophysiology of Parkinson's?
degeneration of substantia nigra, raphe nuclei, locus coeruleus, and the vagus motor nucleus.
What is are the chemical changes associated with Parkinson's?
Decrease in serotonin, dopamine, and noradrenaline. Dysfunction due to imbalance of glutamate and dopamine.
What are the clinical manifestations (symptoms) of Parkinson's?
Slowly progressive. Most common neurological disorder. Bradykinesia= slow movement. Tremors and rigidity.
What treatment is used for Parkinson's and why doesn't administering dopamine work?
L-dopa (precursor). Dopamine can't cross the blood:brain barrier.