PSB Exam 3 Study Guide final 2023

PSB Exam 3 Study Guide final 2023 Voluntary movements require the interaction of which cortical loops (diagram the major structures for each loop and interactions)? - CORRECT ANSWER Cerebellum, Primary and secondary motor cortex, & basal ganglia: ALL IN THE Thalamocortical loop Alpha-gamma co-activation is critical for what? - CORRECT ANSWER -maintain appropriate tension on the spindle organ during contraction of extrafusal fibers -lifting heavy object In the basal ganglia, what is the cascade that follows activation? - CORRECT ANSWER • Motivation and movement selection • At rest, GP inhibits "striatum" thalamic activation of cortex • When striatum is activated, GP is inhibited, allowing thalamus to activate cortex What is the relationship between motor unit size and motor control? - CORRECT ANSWER the smaller the motor unit, the greater the fine motor control What makes up a motor unit? - CORRECT ANSWER Consists of a motor neuron and all the muscle fibers it connects -motor neurons -branches of motor neurons -myofibrils -muscle fiber Mirror neurons are especially interesting to researchers because appear to fire under what conditions - CORRECT ANSWER They appear to trigger specific movements, they fire when a monkey sees another monkey (or human) performing a simple movement previously performed by the monkey itself, they might be part of a neural system for empathy • When the observer is doing the same action • Specific movements • May be for empathy How do muscle spindles work? - CORRECT ANSWER When a skeletal muscle is stretched (carries or lifts a weight) or when antagonistic muscles contract, the muscle spindle's sensory neurons send impulses at a higher frequency than when the muscle is at rest Parkinson's disease is linked to what change in the brain? - CORRECT ANSWER - Degeneration of substantia nigra -Loss of Dopamine → inhibition of thalamocortical loop → less movement Both the basal ganglia and the cerebellum function as generators of spatio-temporal patterns of movement. However, their individual contributions are quite different. Answer the following questions about basal ganglia and cerebellar control of complex movement: - CORRECT ANSWER Basal Ganglia: Function • Controls amplitude and direction of movement • Selection and initiation of slow, continuous, voluntary movements - e.g., smooth pursuit Cerebellum: Function • Error correction of ongoing movement • Motor learning - especially critical in programming rapid movements • Timing • Maintains muscle tone • Balance two symptoms associated with basal ganglia damage - CORRECT ANSWER - uncontrollable arm movements -facial twitches -writhing movements of limbs -tremors -dementia two symptoms associated with cerebellar damage. - CORRECT ANSWER o Muscle weakness (lose tone) o Tremors o Ataxia: balance, posture, coordination problems central pattern generators - CORRECT ANSWER translate brain input into locomotor programs reciprocal inhibition - CORRECT ANSWER antagonist is inhibited when muscle contracts