1 Voltage can be thought of as the driving force (although it is not really a force.) behind current. 2  Things like batteries are voltage sources. 3  The voltage across the terminals of a battery tends to stay pretty constant. 4  When you connect a device across the battery terminals a current flows through the device.
Three types of muscles. The muscular system can be broken down into three types of muscles: skeletal, smooth and cardiac, according to the NIH. Skeletal muscles are the only voluntary muscle tissue in the human body and control every action that a person consciously performs. Most skeletal muscles are attached to two bones across a joint, so the muscle serves to move parts of those bones closer to each other, according to The Merck Manual.
Muscular system has the following important functions in human body; 1  MOVEMENTS OF BODY PARTS: Skeletal muscles are responsible for all voluntary movements of human body parts.2  They provide the force by contracting actively at the expense of energy. MOVEMENTS OF BODY PARTS: Skeletal muscles are responsible for all voluntary movements of human body parts. 2  They provide the force by contracting actively at the expense of energy.