SPLH 620 Test Three Questions With Verified Answers

Two types of motor neurons contained by the central nervous system - Answer 1. Upper motor neuron (UMN) -cerebrum 2. Lower motor neuron (LMN) -brainstem and spinal cord What is the pyramidal system? - Answer -The system responsible for controlling voluntary motor movements (fine controlled, skilled, rapid, etc) -Direct activation pathway, direct motor system -Has only one axonal synapse Two major motor pathways within the pyramidal system - Answer 1. Spinal motor pathway 2. Bulbar motor pathway ???? What does the pyramidal system consist of? - Answer -Cerebral cortex (UMN) -Spinal cord (LMN) Characteristics of UMN damage - Answer -Muscle weakness (decreased ROM) -Decreased control of active movement (slowed movement) -Increased muscle tone (spasticity) -Clonus -"Spastic paralysis" -Contralateral side Characteristics of LMN damage - Answer -Muscle weakness (decreased ROM) -Decreased control of active movement (slowed movement) -Decreased muscle tone (flaccidity) -Decreased reflexes -Fasciculation, fibrillation -Atrophy -"Flaccid dysarthria" -Ipsilateral side Fill in the blank: 1. CN ___: Trigeminal controls ___ 2. CN ___: Facial controls ___ 3. CN ___: Glossopharyngeal controls ___ 4. CN ___: Vagus controls ___ 5. CN ___: Accessory controls ___ 6. CN ___: Hypoglossal controls ___ 7. If there is damage to one of more of these cranial nerves it will lead to ___ dysarthria - Answer 1. V; jaw movement 2. VII; facial movement 3. IX; pharynx 4. X; pharynx and larynx movement 5. XI; neck movement 6. XII; tongue movement 7. Flaccid What is the pathway of the spinal motor pathway? - Answer -UMN: cerebral cortex to spinal cord, descent through internal capsule, decussates in medulla (brainstem), synapse in anterior horn of spinal cord: corticospinal tract, does not go through the thalamus -LMN: cell body in anterior born of SC, synapse with muscle fibers to make a motor unit What is the function of the spinal motor pathway? - Answer - Which pathway is involved in direct motor control of body movements (limb and trunk movement)? - Answer -Spinal motor pathway What is the pathway of the bulbar motor pathway? - Answer -UMN: cerebral cortex to brain, descent through internal capsule, synapse on cranial nerve nuclei: corticobulbar tract, does not go through thalamus -LMN: cell body in cranial nerve nuclei, synapse with muscle fibers to make a motor unit -Specialized for direct control of cranial facial movement (speech and swallowing) How is the bulbar motor pathway organized? - Answer -Corticospinal tract is organized contralaterally -Corticobulbar tract is more complex- bilaterally but there are two exceptions that are organized contralaterally -LMN related to facial nerve (exception) -Genioglossus muscle related to the functioning of the hypoglossal nerve (exception) What is the function of the bulbar motor pathway? - Answer - What do the dorsal and ventral rootles of the spinal cord control? - Answer -Dorsal → sensory -Ventral → motor What is the difference between the spinal cords' horns and its funiculi? - Answer -Horns are the grey matter structure -Funiculi is the white matter surrounding it What is a motor unit? - Answer -Motor neuron + muscle fiber -Motor neuron "activate" with action potential and releases acetylcholine (ACh) -ACh is an excitatory neurotransmitter of the peripheral nervous system What are small vs large motor units in charge of? How are motor units arranged? - Answer -Small: fine control, low force -Large: gross control, high first -Smallest to largest according to needs, managed by the central nervous system What are the three cortical areas for motor control in the pyramidal system? - Answer 1. Premotor 2. Supplementary 3. Broca's What is the internal capsule? - Answer -White matter structure consisting of both ascending and descending fibers for the motor and sensory pathways -Contains a collection of axons What is the extrapyramidal system? - Answer -Provides framework on which skilled actions can be accomplished, controls posture and tone, regulates reflexes (involuntary) -Indirect activation pathway -Source of input to LMNs via multiple synapses -Smaller, short, "local," circuits What are the three structures within the extrapyramidal system? - Answer 1. Basal ganglia 2. Cerebellum 3. Brainstem After motor commands are generated they are sent to the - Answer -Basal ganglia The basal ganglia functions to ___ and the outcome is to ___ - Answer -Issue authorization commands to initiate or inhibit speech motor actions -Generate speech motor movements like pharynx and larynx Order of basal ganglia direct pathway - Answer -Cortex -- straitum (excitatory +1) -Straitum -- GPi and SNr (inhibitory -1) -GPi and SNr -- thalamus (inhibitory -1) -Thalamus -- cortex excitatory +1) Order of basal ganglia indirect pathway - Answer -Cortex -- straitum (excitatory +1) -Straitum -- GPe (inhibitory -1) -GPe -- sunthalic nucleus (inhibitory -1) -Sunthalic nucleus -- GPi (excitatory +1) -GPi -- thalamus (inhibitory -1) What are the three parts of the basal ganglion that send input and output? - Answer 1. Striatum: receives input from cortex 2. Globus pallidus: sends output to thalamus 3. Substantia nigra: sends output to superior colliculus