Functional anatomy of the association between motor units and muscle receptors
TLDR
Consideration of the functional anatomy of the association between motor units and muscle receptors suggests the need for detailed structural-functional analyses of those muscles with specializations in architecture, fiber-type composition and distribution, and in the number and distribution of their muscle spindles and tendon organs.Abstract:
Muscle spindles and tendon organs occur in most somatic muscles of the mammal and are particularly concentrated in muscles subserving fine movements, including postural muscles and small muscles of the distal extremities. In those mixed muscles in which the different fiber and motor unit types are “compartmentalized,” the spindles, and perhaps tendon organs also, are virtually limited to those compartments predominated by “oxidative” muscle fibers. These morphological observations based on a broad array of muscles in many species, complement electrophysiological studies which have emphasized that (1) the “oxidative” motor units have low reflex thresholds and (2) segmental proprioceptive reflexes may be primarily concerned with the control of finely graded contractions. Consideration of the functional anatomy of the association between motor units and muscle receptors suggests the need for detailed structural-functional analyses of those muscles with specializations in architecture, fiber-type composition and distribution, and in the number and distribution of their muscle spindles and tendon organs. An electrophysiological analysis of the relationship between the spinal cord and such muscles might also reveal certain strategies and mechanisms underlying segmental motor control which are either absent or obscured in the analysis of that select number of “homogenously-mixed” muscles conventionally used in the study of the mammalian segmental motor control system.read more
Citations
More filters
OtherDOI
Motor Units: Anatomy, Physiology, and Functional Organization
TL;DR: The sections in this article are: Motor Unit Types: Histochemical Profiles and Ultrastructural Correlations, Anatomical Considerations, and Control of Muscular Action: Recruitment and Rate Modulation.
Book
Speech Perception By Ear and Eye: A Paradigm for Psychological Inquiry
TL;DR: In this paper, the processing of information in face-to-face communication when a speaker makes both audible and visible information available to a perceiver is discussed. But the evaluation of the information source provides information about the strength of alternative interpretations, rather than just all-or-none categorical information, as claimed by "categorical perception" theory.
Journal ArticleDOI
Does the nervous system use equilibrium-point control to guide single and multiple joint movements?
TL;DR: The hypothesis that the central nervous system generates movement as a shift of the limb's equilibrium posture has been corroborated experimentally in studies involving single- and multijoint motions and can now be investigated in the neurophysiological machinery of the spinal cord.
Journal ArticleDOI
What muscle variable(s) does the nervous system control in limb movements
TL;DR: It is concluded that different physical variables can be controlled depending on the type of limb movement required, and the concept of stiffness regulation should probably be extended to the regulation of the visco-elastic properties of a muscle or joint.
Journal ArticleDOI
Selfishness examined: Cooperation in the absence of egoistic incentives.
TL;DR: In a series of experimental social dilemmas, subjects were instructed to make single, anonymous choices about whether or not to contribute money for a shared "bonus" that would be provided only if enough other people in the group also contributed their money as discussed by the authors.
References
More filters
Journal ArticleDOI
Metabolic profiles of three fiber types of skeletal muscle in guinea pigs and rabbits.
Journal ArticleDOI
Mammalian muscle receptors and their central actions
Journal ArticleDOI
Improvement in linearity and regulation of stiffness that results from actions of stretch reflex.
T. R. Nichols,James C. Houk +1 more
TL;DR: The results support two complementary hypotheses: a) stiffness may be the regulated property of the stretch reflex, and b) the main function of autogenetic reflexes may be to conpensate for variations in the properties of skeletal muscle rather than to oppose changes in load.
Journal ArticleDOI
Relations between structure and function in the design of skeletal muscles.
Elwood Henneman,Camille B. Olson +1 more
TL;DR: It is shown that the excitability of motoneurons is an inverse function of their size, and the participation of a motor unit in graded motor activity is dictated by the size of its neuron.
Journal ArticleDOI
Regulatory actions of human stretch reflex
TL;DR: It is confirmed that most subjects can suppress triggered reactions when the instruction calls for no intervention, leaving an unmodified reflex response, which implies the existence of and compensation for nonlinear muscle mechanical properties.
Related Papers (5)
Morphology and distribution of muscle spindles in dorsal muscles of the cat neck.
F. J. Richmond,V. C. Abrahams +1 more
Forces produced by medial gastrocnemius and soleus muscles during locomotion in freely moving cats.
The sensitivity of muscle spindle afferents to small sinusoidal changes of length
P. B. C. Matthews,R. B. Stein +1 more