The length of the thick filament is the A band. The A band contains both thick and thin filament because they are overlapping each other. The H band is thick filament only, however, it only covers a portion of width of the thick filament.
A lamp with a thick filament will draw more current. What restricts the current flow in the filament is the resistance of the filament which increases as the temperature of the filament increases. A thin filament requires less energy to get heated up that a thick one so less current to achieve threshold resistance. Also a thick filament provides a broader path for current so there is less resistance per increase in degree centigrade. For these two (closely related but distinct) reasons it will require more current for the filament to get heated up to threshold resistance.
A lamp with a thick filament will draw more current. What restricts the current flow in the filament is the resistance of the filament which increases as the temperature of the filament increases. A thin filament requires less energy to get heated up that a thick one so less current to achieve threshold resistance. Also a thick filament provides a broader path for current so there is less resistance per increase in degree centigrade. For these two (closely related but distinct) reasons it will require more current for the filament to get heated up to threshold resistance.
the filament is neither too thick nor too light
thin
Myofilaments Two types: actin (thin filament) & myosin (thick filament)
myosin
the myofilaments themselves do not contract, they slide, this is called the Sliding Filament theory, in which the thick filament (Myosin) slides over the thin filament (Actin).
The thick filament is composed of the myosin molecule. The thin filament is composed of the actin molecule. Flexing the head of myosin provides the powerstroke.
thick filaments
The thin filament sites remain open to the binding and stroke of the thick filament and there would be no muscle relaxation without the reuptake of Ca 2+ so the thin filament sites are closed.
Calcium ions bind to the thin filament ( actin ), turn it and expose the binding site to the thick filament (myosin ).