The extrapyramidal system is the system involved in execution of movement.
The planning area for movement is a region of the cortex anterior to the primary motor cortex.
In the somatosensory cortex homunculus, the neurons that initate movement in the ❌ lie in the medial cortex and the neurons that initiate movement in the ❌ lie in the lateral cortex.
Which area is not represented with an increase in size in the somatosensory homunculus?
Tongue
Fingers
Trunk
Nose
A single anterior horn cell (AHC) and all the muscle fibers it innervates is called a "motor unit."
Label Corticospinal tract
Neurons in the primary motor cortex initiate movement of the contralateral side of the body.
A lesion of the lateral corticospinal tract at the upper cervical cord results in ipsilateral contralateral( ipsilateral, contralateral ) weakness of the whole left side of the body. A lesion involving the corticospinal tract in the right hemisphere of the brain results in right-sided left-sided( right-sided, left-sided ) weakness.
Upper motor neuron lesions result in:
Babinsky sign
Spasticity
Hypotonia and hyporeflexia
Hypertonia and hyperreflexia
Clonus
Fasciculations
Which of the following is NOT a typical result of a lower motor neuron lesion?
Fasciculations and fibrillations
Can affect a single muscle
Toe goes up on touching bottom of foot
Decreased muscle tone
Extrapyramidal motor system is similar to the pyramidal system in that both send projections to anterior horn cells in the spinal cord.
Nuclei in the extrapyramidal motor system include:
Medial pre-optic area
Substantia nigra
Subthalamic nucleus
Basal ganglia
Septal nuclei
What is an autosomal dominant genetic disease that causes a loss of neurons in the caudate and putamen involved in the indirect pathway?
Huntington's chorea
Hemiballismus
Parkinson's disease
Myasthenia gravis
Hemiballismus is caused by:
A decreased excitatory drive of the cortex
The subthalamic nucleus stops working resulting in less activation of the globus pallidus, less inhibition of the motor nuclei of the thalamus (VA/VL), and excessive excitatory input to the motor cortex
Disinhibition via decrease in GABA and increase in glutamate in the motor cortex
Loss of dopamine from substantia nigra can result in which of the following clinical features?
Bradykinesia
Resting tremor
Flinging arm movements
Shuffling gait
Transcortical motor aphasia
Decreased affect
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