Biomaterial Database

Regularity of muscle spindle receptor discharges at a different muscle length. 1984

V I Zalkind

The regularity of receptor discharges of passive muscle spindles adapted to a different length of the triceps of the calf of narcotized cats was investigated in the range of average frequencies from 5.6 to 40 impulses/sec. The values of the coefficients of variation of the impulse intervals in discharges of the primary endings are distributed in the range from 2.5 to 18.0% and of the secondary from 1.2 to 12%. The discharges of the primary endings are less variable than the discharges of the primary. Among the latter are found receptors with less, moderately, and more regular discharges at any length of the muscle. The shape of the "average impulse interval vs. coefficient of variation" relationship is nonlinear and differs for different units. For samples of receptors having approximately the same variability of the impulse intervals the average values of the coefficients of variation decrease significantly with muscle tension and increase of the rate of impulse flow. In some cases a decrease of the values of the coefficients of variation occurs due to a decrease of the dispersion at the same rate of flow and in other cases both parameters change simultaneously. A decrease of the dispersion of the intervals in receptor discharges apparently reflects an increase of the number of uniformly depolarized endings as their tension increases.

UI	MeSH Term	Description	Entries
D009470	Muscle Spindles	Skeletal muscle structures that function as the MECHANORECEPTORS responsible for the stretch or myotactic reflex (REFLEX, STRETCH). They are composed of a bundle of encapsulated SKELETAL MUSCLE FIBERS, i.e., the intrafusal fibers (nuclear bag 1 fibers, nuclear bag 2 fibers, and nuclear chain fibers) innervated by SENSORY NEURONS.	Muscle Stretch Receptors,Neuromuscular Spindles,Receptors, Stretch, Muscle,Stretch Receptors, Muscle,Muscle Spindle,Muscle Stretch Receptor,Neuromuscular Spindle,Receptor, Muscle Stretch,Receptors, Muscle Stretch,Spindle, Muscle,Spindle, Neuromuscular,Spindles, Muscle,Spindles, Neuromuscular,Stretch Receptor, Muscle
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor