Voluntary activation. A muscle is activated voluntarily when force is produced by the recruitment of motoneurons through increased descending drive from the motor cortex. This activation is usually deliberate and is accompanied by a sense of effort. There are many other influences on motoneurons at rest and during voluntary contractions that may alter the response of motoneurons to descending d...

Voluntary activation. A muscle is activated voluntarily when force is produced by the recruitment of motoneurons through increased descending drive from the motor cortex. This activation is usually deliberate and is accompanied by a sense of effort. There are many other influences on motoneurons at rest and during voluntary contractions that may alter the response of motoneurons to descending d...

sarcomere shortening, by the "isovelocity release" technique. Contractile activation was varied by changing the calcium concentration in the bathing medium ([Ca2+J0). Slack SL was 1.85 ±0.04 ,m. When length of the muscle was held constant, the sarcomeres in the central region of the muscle shortened during the twitch by up to 21%. Both peak sarcomere isometric twitch force and unloaded velocity...

We studied the effect of aminophylline on twitch tension (TT) and intracellular pH (pHi) in isolated rat diaphragm strips that were fatigued, hypercapnic, or hypoxic. Superfused muscles were directly stimulated at 0.5 Hz. The pHi was measured from distribution volumes of dimethyl-oxazolidinedione. Fatigue was induced by intermittent tetanic stimulation. Hypercapnia and hypoxia were produced by ...

Localization microscopy is a fairly recently introduced super-resolution fluorescence imaging modality capable of achieving nanometre-scale resolution. We have applied the dSTORM variation of this method to image intracellular molecular assemblies in skeletal muscle fibres which are large cells that critically rely on nanoscale signalling domains, the triads. Immunofluorescence staining in fixe...

The aim of this study was to compare the mechanical and electromyographic (EMG) characteristics of soleus motor units activated during maximal H reflex and direct M response among subjects with different histories of physical activity. Power-trained athletes produced stronger twitches, with a higher rate of twitch tension buildup and relaxation, than their endurance counterparts for both maxima...

Abstract Goose meat is increasingly popular among consumers because of its good quality. The fiber characteristics have been well demonstrated to be key contributing factors quality, and the marketable ages are also closely related However, little known about effect different on quality goose through characteristics. Here, Yangzhou geese (70, 90, 120 d) their were investigated. results showed t...

The form, function and fibre-type profiles of the ilio-marsupialis muscles, branches of which insert on to the skin of the nipples and pouch, have been investigated in the small dasyurid marsupial Sminthopsis douglasi. Single fibres from the branches of muscles associated with unsuckled nipples in non-lactating females and with both unsuckled and suckled nipples at four stages during the 70-day...

BARNARD, R. JAMES, V. REGGIE EDGERTON, TETSUO FURUKAWA, AND J. B. PETER. Histochemical, biochemical, and contractile properties of red, white, and intermediate jibers. Am. J. Physiol. 220 (2) : 41 O-41 4. 197 1 .-Individual fibers from guinea pig muscles (soleus, flexor hallucis longus (FHL), flexor digitorium longus (FDL), medial gastrocnemius (MG) and the portion of the vastus lateralis (RV) ...