title: Action of the sympathetic system on skeletal muscle.
abstract: The action exerted by the sympathetic system on skeletal muscle is briefly reviewed with regard to the effects induced by the adrenergic mediator on extra-fusal muscle fibre contractility and on muscle spindle receptor organs. In particular, the different responses of slow - and fast - contracting muscles to catecholamine administration and to sympathetic stimulation are reported. Also, the sympathetically--induced effects on muscle spindle afferent activity are discussed on the basis of recent anatomical and functional data suggesting the existence of a direct action exerted by noradrenergic axons on intrafusal muscle fibres. Some of the possible implications of these data are then briefly mentioned.
authors.affiliation: Istituto di Fisiologia Umana-Università Cattolica S. Cuore, Roma.
authors.forename: C
authors.initials: C
authors.lastname: Grassi
authors.forename: M
authors.initials: M
authors.lastname: Passatore
mesh_terms: D006801:Humans; D009119:Muscle Contraction; D009470:Muscle Spindles / Q000502:physiology; D009132:Muscles / Q000294:innervation / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*