Gaps in spindle physiology: Why the tandem spindle?
Most reviews of spindle structure and function have focussed on the operation of a “model” muscle spindle, which exists as a single encapsulated receptor with a single sensory zone and a predictable pattern of nerve supply. The description accurately depicts the majority of muscle spindles in cat limb muscles where most studies of muscle spindles have been carried out. It also provides a model which fits many of our developing concepts about the role of the muscle spindle in motor control. Why, then, are there muscle spindles which do not exist as single encapsulations but as groups of receptors in different types of assemblages? One such muscle spindle, the tandem muscle spindle, has been recently examined in detailed anatomical studies. The results suggest that the tandem spindle may be a specialized proprioceptive organ, but neither the physiology nor the central projections of this receptor are yet understood.
KeywordsMuscle Spindle Medial Gastrocnemius Neck Muscle Sensory Innervation Intrafusal Fibre
Unable to display preview. Download preview PDF.
- Bakker, G. J. and Richmond, F. J. R. (1981) Two types of muscle spindles in cat neck muscles: a histochemical study of intrafusal fiber composition. J. Neurophysiol. 45: 973–986.Google Scholar
- Bakker, D.A. and Richmond, F.J.R. (1982) Muscle spindle complexes in muscles around upper cervical vertebrae in the cat. J. Neurophysiol. 48: 62–74.Google Scholar
- Banks, R.W. (1981) A histological study of the motor innervation of the cat’s muscle spindle. J. Anat. 133: 571–579.Google Scholar
- Banks, R.W., Ellaway, P.H. and Scott, J.J. (1980) Responses of de-efferented muscle spindles of peroneus brevis and tertius muscles in the cat. J. Physiol. (Lond.) 310: 53P.Google Scholar
- Banks, R.W., Barker, D. and Stacey, M.J. (1982) Form and distribution of sensory terminals in cat hindlimb muscle spindles. Phil. Trans. R. Soc. Lond., B 299: 329–364.Google Scholar
- Barker, D. and Ip, M.C. (1961) A study of single and tandem types of muscle-spindle in the cat. Proc. Roy. Soc., B 154: 377–397Google Scholar
- Boyd, I.A. (1981) The action of the three types of intrafusal fibre in isolated cat muscle spindles on the dynamic and length sensitivities of primary and secondary sensory endings. In: Muscle Receptors and Movement. Taylor, A. and Prochazka, A. eds., London: Macmillan pp. 17–32.CrossRefGoogle Scholar
- Cooper, S. and Daniel, P.M. (1963) Muscle spindles in man; their morphology in the lumbricals and the deep muscles of the neck. Brain 86: 563–586.Google Scholar
- Goldfinger, M.D. and Fukami, Y. (1982) Distribution, density and size of muscle receptors in cat tail dorsolateral muscles. J. Anat. 135: 371–384.Google Scholar
- Keane, J.M. (1981) Peripheral organization of the trapezius muscle complex in the cat. M.Sc. Thesis. Queen’s University, Kingston. p. 76.Google Scholar
- Kucera, J. (1982) One-bag-fiber muscle spindles in tenuissimus muscles of the cat. Histochem. 76: 315–328.Google Scholar
- Matthews, P.B.C. (1981) Muscle spindles: their messages and their fusimotor supply. In: Handbook of Physiology — The Nervous System II., V.B. Brooks ed., Bethesda: Amer. Physiol. Soc. pp. 189–228.Google Scholar
- Richmond, F.J.R. and Abrahams, V.C. (1975) Morphology and distribution of’ muscle spindles in dorsal muscles of the cat neck. J. Neurophysiol. 38: 1322–1339.Google Scholar
- Richmond, F.J.R. and Abrahams, V.C. (1979) Physiological properties of muscle spindles in dorsal neck muscles of the cat. J. Neurophysiol. 42: 604–617.Google Scholar
- Swett, J.E. and Eldred, E. (1960a) Distribution and numbers of stretch receptors in medial gastrocnemius and soleus muscles of the cat. Anat. Rec. 137: 453460.Google Scholar
- Swett, J.E. and Eldred, E. (1960b) Comparisons in structure of stretch receptors in medial gastrocnemius and soleus muscles of the cat. Anat. Rec. 137: 461–473.Google Scholar
- Thompson, J. (1970) Parallel spindle systems in the small muscles of the rat tail. J. Physiol. (Lond.)n 211: 781–799.Google Scholar