BIOS1171 Lecture Notes - Lecture 20: Noxious Stimulus, Golgi Tendon Organ, Hyporeflexia

• School: University of Sydney
• Department: Biomedical Science
• Course: BIOS1171
• Professor: Jin Huang

Document Summary

Tonic & phasic inputs to mu: locomotor (movement): Precision depends on number of muscle fibres innervated. Ia = afferent = wraps around muscle spindle, brings information in & synapses onto the lmn. Ib = gto afferent (come from golgi tendon organ) & adjusts muscle contraction: synapse onto inhibitory motor neuron which releases inhibitory neurotransmitter to prevent firing & cause muscle relaxation. Muscle tone: amount of stiffness in a resting muscle, clinically assessed using passive range of motion, tone is maintained by small motor units that are tonically active. Lmn lesion: muscle tone, voluntary muscle activity, tendon reflex activity, hypotonia floppy muscles, low tone in muscle, cannot move muscles (paresis lose voluntary control) lose all input to muscle, hypo-reflexia (or absence of reflexes) Umn lesion: muscle tone, hypertonia stiff muscles. Increases reflexes due to increased tone in muscle: tendon reflex activity, hyper-reflexia, voluntary muscle activity, cannot move muscles (paresis); no voluntary muscle activity.