Nervous System Physiology Part 10 Flashcards
In Parkinson Disease;
• Input to the basal nuclei is diminished.
• Interplay of excitatory and inhibitory circuits is unbalanced.
• Activation of the motor cortex (via basal nuclei–thalamus circuit) is reduced.
Parkinson disease is characterized by;
• Akinesia (reduced movement)
• Bradykinesia (slow movement)
• Rigidity
• Resting tremor
Parkinson Disease symptoms
• Parkinsonian gait
• Mask-like face
• Slowed movement
• Reduced arm swing
• Rigidity
• Asymmetric resting tremor
• Freezing
• Postural instability
• Shuffling steps
What are the Cerebellum Subdivisions?
• Vestibulocerebellum – Balance and eye movements
• Spinocerebellum – Body and limb movement coordination
• Corticocerebellum – Planning and timing of movements
Function of Vestibulocerebellum
Controls equilibrium
In people with Vestibulocerebellum dysfunction:
Equilibrium is far more disturbed during performance of rapid motions than during stasis, especially when these movements involve changes in direction of movement and stimulate the semicircular ducts.
Spinocerebellum: Info Types when a movement is formed
- Info from cerebral motor cortex & midbrain red nucleus → Intended sequential plan of movement the next few fractions of a second.
Feedback info from peripheral parts of the body (especially distal proprioceptors of the limbs) → what Actual movements result
Functions of Spinocerebellum
• Compares intended movement with actual performance
• Detects discrepancies between them
• Sends error signals to motor cortex & subcortical centers
• Allows for real-time correction of movements
What does the planning of sequential movements require?
That the corticocerebellum communicates with both the premotor and sensory portions of the cerebral cortex, and it requires two–way communication between these cerebral cortex areas with corresponding areas of the basal ganglia.
Function of Corticocerebellum
Corticocerebellum plays important roles in planning and
“timing” of sequential movements, which makes sure the individual can progress smoothly from one movement to the next in orderly succession.
What is ANS?
Autonomic nervous system (ANS) is the system of motor neurons that innervates smooth and cardiac muscle and glands.
What is the function of the ANS?
At every moment, signals stream from visceral organs into the CNS, and autonomic nerves make adjustments as necessary to ensure optimal support for body activities.
What is the ANS made up of?
Two neurons in series that connect the CNS and the effector cells.
Where is the cell body of the first Neuron in the ANS found?
• The first neuron has its cell body in the CNS.
Where is the synapse between the two neurons that make up the ANS?
The synapse between the two neurons is outside the CNS in a cell cluster called an autonomic ganglion.
What are the names of the neurons passing between the CNS and the ganglia?
preganglionic neurons
What are the names of neurons passing between the ganglia and the effector cells ?
postganglionic neurons.
Do the neurons of the sympathetic and parasympathetic divisions leave the CNS at the same levels?
different levels
Sympathetic divisions leave the CNS from the…..
thoracic (chest) and lumbar
regions of the spinal cord.
The parasympathetic division leaves the CNS from the….
the brainstem and the sacral portion of the spinal cord.
Where does most of the sympathetic ganglia lie?
close to the spinal cord and form the two chains of ganglia known as the sympathetic trunks.
What are the few other sympathetic ganglia called?
collateral ganglia
What are the few ganglia that make up the collateral ganglia?
celiac, superior mesenteric, and inferior mesenteric ganglia
