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The basic reflex arc and spinal cord circuitry. Basic Spinal Anatomy. Transversal cut of the spinal cord. Basic Spinal Anatomy. Muscle spindles. Motoneurons targetting muscles. Golgi tendon organs. Soma of the motoneurons. Sensory information. Tactile, pain, thermic receptors on the skin.
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Basic Spinal Anatomy Transversal cut of the spinal cord
Basic Spinal Anatomy Muscle spindles Motoneurons targetting muscles Golgi tendon organs Soma of the motoneurons Sensory information Tactile, pain, thermic receptors on the skin
How is the sensory-motor circuitry organized? ? Sensory input Motor output
Stretch reflex • Reciprocal innervation and synergist connections
Stretch reflex • Reciprocal innervation and synergist connections • Simplify the commands from higher levels necessary to control of voluntary movements • Corticospinal connexions can modulate the reciprocal connectivity
Stretch reflex • Reciprocal innervation and synergist connections • Simplify the commands from higher levels necessary to control of voluntary movements • Corticospinal connexions can modulate the reciprocal connectivity
Withdrawal reflex • Reciprocal innervation and synergist connections • Simplify the commands from higher levels necessary to control of voluntary movements • Corticospinal connexions can modulate the reciprocal connectivity • Cross-connections • Coordination necessary for the control of posture
Vertical Connections • Reciprocal innervation and synergist connections • Simplify the commands from higher levels necessary to control of voluntary movements • Corticospinal connexions can modulate the reciprocal connectivity • Cross-connections • Coordination necessary for the control of posture
Convergence of sensory informations • Reciprocal innervation and synergist connections • Simplify the commands from higher levels necessary to control of voluntary movements • Corticospinal connexions can modulate the reciprocal connectivity • Cross-connections • Coordination necessary for the control of posture • Convergence of sensory input
Are reflexes streotyped ? Corticospinal connections can shape the reflexes in order to adapt to different contexts
Conclusion Spinal cord circuitry forms the infrastructure that is exploited by supraspinal areas in order to coordinat different muscle The input output relation is far from a streotyped relation Since it can be shaped in order to adapt to the behavioral states of the organism