Movement Flashcards
Final common pathway
skeletal muscles can only be reached through the spinal or brainstem motoneuron
Somatotopy
topography in the somatosensory and motor system
Intrafusal fiber
modified muscle fiber in the muscle spindle
Extrafusal fiber
muscle fibers outside the muscle spindle
Annulospiral ending
terminal of the Ia fiber on the intrafusal fiber
Miotatic reflex (stretch reflex)
monosynaptic reflex starting from the muscle spindle and causing contraction of the muscle on stretching
Inverse miotatic reflex (tendon reflex)
bisynaptic reflex starting from the tendon organ
Motor unit
collection of muscle fibers innervated by the same motoneuron
Motoneuron pool
collection of motoneurons innervating muscle units in the same muscle
Red muscle fiber
muscle fiber characterized by good blood supply, many mitochondria, high myoglobin content and slow fatigue
White muscle fiber
muscle fiber characterized by few mitochondria, low myoglobin content, quick fatigue, but very fast contraction
Renshaw neuron
inhibitory neuron in the spinal cord excited by a collateral of the alpha motoneuron and providing negative feedback to the motoneuron
Decerebrate rigidity
increase of the muscle tone caused by the transection of the brain stem above the Deiter´s nucleus
Muscle tone
continuous, slight contraction of the skeletal muscles important in the maintenance of the posture
Purkinje neuron
GABAergic inhibitory neuron providing the main output of the cerebellum