BMS 300 Lecture Notes - Lecture 19: Nuclear Bag Fiber, Intrafusal Muscle Fiber, Gamma Motor Neuron

• School: Quinnipiac University
• Department: Biomedical Sciences
• Course: BMS 300
• Professor: Thomas Martin

Document Summary

Internal stretch of muscle spindle: activating the gamma motor neurons that stimulates distal ends of the intrafusal fibers to contract, thereby stretching the spindle, muscle contraction: must have coactivation of the alpha motor and gamma motor neurons. Important: send signals to brain when levels of oxygen and co2 change to get more resources to that muscle. Immediate but not delicate or precise: visceral reflexes, autonomic reflexes, control or adjust the activities of smooth and cardiac, complexity of circuit muscles, glands etc, monosynaptic reflex. Involves one synapse in the cns: direct connection between the sensory and motor neurons, motor neuron serves as the processing site, faster reflexes, polysynaptic reflexes, majority of reflexes, longer delay between stimulus and response. Involve at least one interneuron: reflexes, some reflexes involve excitatory neurons, result in a response, ex: muscle contraction, some reflexes involve inhibitory neurons, result in inhibition of a response, ex: relaxation of muscle, spinal somatic reflexes.