During contractions, regulation of microvascular oxygen partial pressure (Pmv(O2)), which drives blood-myocyte O2 flux, is a function of skeletal muscle fiber type and oxidative capacity and can be altered by exercise training. The kinetics of Pmv(O2) during contractions in predominantly fast-twitch muscles evinces a more rapid fall to far lower levels compared with slow-twitch counterparts. Pe...

Birds utilize one of two hindlimb postures during flight: an extended posture (with the hip and knee joints flexed, while the ankle joint is extended caudally) or a flexed posture (with the hip, knee, and ankle joints flexed beneath the body). American Avocets (Recurvirostra americana) and Black-necked Stilts (Himantopus mexicanus) extend their legs caudally during flight and support them for e...

Twitch fiber bundles from a slow (soleus) and a fast (extensor digitorum longus) mammalian muscle after mild chemical treatment were activated with calcium and relaxed in calcium-free solution. Like the electrically activated whole muscles, the force-velocity relationship was such that, at each relative load, the steady speed of shortening for the fast fibers was about two times greater than th...

The jaw muscles of a turtle [Mauremys (Clemmys) japonica (MCJ)], have been analyzed for the histochemical characteristics of their fiber types. Six jaw muscles of the MCJ have been analyzed for histochemical characteristics of their fiber types. In this study, fiber types in two groups of muscles are classified; 1) fast twitch glycolytic (FG), fast twitch oxidative glycolytic (FOG), slow twitch...

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...

Aerobic Power (VO2 max) and anaerobic power were estimated in medical students before and after six weeks of yogic training. A significant increase in aerobic power and a significant decrease in anaerobic power was observed. This may be due to conversion of some of the Fast Twitch (F.T.) muscle fibres into Slow Twitch fibres (S.T.) during yogic training.

The sarco-endoplasmic reticulum Ca2+ ATP-ase (SERCA) and myosin heavy chain (MyHC) levels were measured in hindlimb-denervated and selectively denervated rat soleus muscles. Selective denervation allowed passive movement of the soleus, whereas hindlimb denervation rendered it to passivity. To minimize chronic effects, we followed the changes only for 2 weeks. Selective denervation resulted in l...