Final answer:
Muscle contraction and its electrical properties are determined by factors such as the sliding filament model, ATP, calcium ions, neurotransmitters, and the nervous system.
Step-by-step explanation:
The specific contractile and electrical properties of muscles are determined by several factors. In general, the sliding filament model of muscle contraction explains how muscle fibers generate force and shorten to produce movement. This involves the interaction between actin and myosin filaments, as well as the release of calcium ions (Ca2+). ATP provides the energy for cross-bridge formation and filament sliding. Additionally, the electrical properties of muscles, such as the ability to initiate an electrical potential and propagate it rapidly, are influenced by factors like neurotransmitters and the involvement of the nervous system.