Where is myoglobin found?

Bone-dissolving cells are known as..........

Muscle fatigue occurs due to the accumulation of . . . . . . .

At which site do muscle fibers receive stimulation from a motor neuron?

What are $P, Q,$ and $R$ in the given diagram?
$P \quad\quad Q \quad \quad R$

In the thin filament of skeletal muscle fibre,a small globular protein that masks the active sites for myosin on the $F-$actin,is