Flashcards in Lecture 22: Locomotion Deck (44)
an activity leading to a change in the location of the body in external space.
Examples of locomotion
walking, running, hopping, swimming, flying, crawling, etc.
Important characteristics of locomotion
-relation between the support and swing phases
-relative timing of the extremities (gait)
Two different views of Locomotion
1. Motor Programming
2. Dynamic Systems
Central Pattern Generator: hypothetical neural structure that generates a neural activity, activity is transformed into rhythmic muscle activity, leading to rhythmic behavior
rhythmicity of locomotion is caused by interaction of neural activity and the periphery
Early Views of Locomotion
-Locomotion was a pattern produced by alternating reflex responses.
-Voluntary movement is a result of modulating reflexes
Rhythmic motor pattern of locomotion was produced by a special neural network(CPG) that could produce activity even in the absence of reflexes
A CPG is
a hypothetical structure in the central nervous system that can generate patterned (rhythmical) activity
CPG can be driven by _______ as well as by peripheral information
-Both sources of information can lead to gait changes
CPG involves ______ types of cells.
CPG: Cells of two types act on each other and ________.
suppress each other's activity.
CPG: Cells either fatigue quickly or turn off after a brief period of activity, allowing _____.
the other group to be released from inhibition and take over.
Cycle continues until an external influence turns off both groups of cells.
Neurons of the 3rd group provide ___________.
input that can both excite and suppress the cells of the 1st two groups
Problems w/CPG: ______ higher center
Problems w/CPG: ______ input could change the pattern of gait activity
Problems w/CPG: Difficult to determine if changes in ____ are produced by higher center or peripheral input.
Problems w/CPG: Many important variable lack _____.
a good definition
Problems w/CPG: This drove the development of _____.
dynamic systems approach
Stimulating _____ of cats led to rhythmic moments of the cat's limbs
Different levels of stimulation could _________ locomotion.
slow down or speed up
Locomotor Strip is in the ____.
upper cervical region of the spinal cord
________ of certain brain areas can induce locomotion
______ changes with the strength of the stimulation.
Locomotion and gait changed can also be induced by ______.
treadmill motion and by intraspinal drugs
________ locomotion can be see.
Graham Brown v. Sherrington: The spinal is likely to contain one, two, to even four _________.
Central Pattern Generators
Graham Brown v. Sherrington: A CPG can be driven by _____.
descending and ascending signals.